Developer Guide
Red Hat JBoss Data Grid 6.3
For use with Red Hat JBoss Data Grid 6.3.2
Abstract
An advanced guide intended for developers using Red Hat JBoss Data Grid 6.3.2
Part I. Programmable APIs
Red Hat JBoss Data Grid provides the following programmable APIs:
- Cache
- Batching
- Grouping
- Persistence (formerly CacheStore)
- ConfigurationBuilder
- Externalizable
- Notification (also known as the Listener API because it deals with Notifications and Listeners)
Chapter 1. The Cache API
The Cache interface provides simple methods for the addition, retrieval and removal of entries, which includes atomic mechanisms exposed by the JDK's
ConcurrentMap interface. How entries are stored depends on the cache mode in use. For example, an entry may be replicated to a remote node or an entry may be looked up in a cache store.
The Cache API is used in the same manner as the JDK Map API for basic tasks. This simplifies the process of migrating from Map-based, simple in-memory caches to Red Hat JBoss Data Grid's cache.
Note
This API is not available in JBoss Data Grid's Remote Client-Server Mode
1.1. Using the ConfigurationBuilder API to Configure the Cache API
Red Hat JBoss Data Grid uses a ConfigurationBuilder API to configure caches.
Caches are configured programmatically using the
ConfigurationBuilder helper object.
The following is an example of a synchronously replicated cache configured programmatically using the ConfigurationBuilder API:
Example 1.1. Programmatic Cache Configuration
Configuration c = new ConfigurationBuilder().clustering().cacheMode(CacheMode.REPL_SYNC).build();
String newCacheName = "repl";
manager.defineConfiguration(newCacheName, c);
Cache<String, String> cache = manager.getCache(newCacheName);
Configuration Explanation:
An explanation of each line of the provided configuration is as follows:
Configuration c = new ConfigurationBuilder().clustering().cacheMode(CacheMode.REPL_SYNC).build();
In the first line of the configuration, a new cache configuration object (namedc) is created using theConfigurationBuilder. Configurationcis assigned the default values for all cache configuration options except the cache mode, which is overridden and set to synchronous replication (REPL_SYNC).String newCacheName = "repl";
In the second line of the configuration, a new variable (of typeString) is created and assigned the valuerepl.manager.defineConfiguration(newCacheName, c);
In the third line of the configuration, the cache manager is used to define a named cache configuration for itself. This named cache configuration is calledrepland its configuration is based on the configuration provided for cache configurationcin the first line.Cache<String, String> cache = manager.getCache(newCacheName);
In the fourth line of the configuration, the cache manager is used to obtain a reference to the unique instance of thereplthat is held by the cache manager. This cache instance is now ready to be used to perform operations to store and retrieve data.
Note
JBoss EAP includes its own underlying JMX. This can cause a collision when using the sample code with JBoss EAP and display an error such as
org.infinispan.jmx.JmxDomainConflictException: Domain already registered org.infinispan.
To avoid this, configure global configuration as follows:
GlobalConfiguration glob = new GlobalConfigurationBuilder()
.clusteredDefault()
.globalJmxStatistics()
.allowDuplicateDomains(true)
.enable()
.build();
1.2. Per-Invocation Flags
Per-invocation flags can be used with data grids in Red Hat JBoss Data Grid to specify behavior for each cache call. Per-invocation flags facilitate the implementation of potentially time saving optimizations.
1.2.1. Per-Invocation Flag Functions
The
putForExternalRead() method in Red Hat JBoss Data Grid's Cache API uses flags internally. This method can load a JBoss Data Grid cache with data loaded from an external resource. To improve the efficiency of this call, JBoss Data Grid calls a normal put operation passing the following flags:
- The
ZERO_LOCK_ACQUISITION_TIMEOUTflag: JBoss Data Grid uses an almost zero lock acquisition time when loading data from an external source into a cache. - The
FAIL_SILENTLYflag: If the locks cannot be acquired, JBoss Data Grid fails silently without throwing any lock acquisition exceptions. - The
FORCE_ASYNCHRONOUSflag: If clustered, the cache replicates asynchronously, irrespective of the cache mode set. As a result, a response from other nodes is not required.
Combining the flags above significantly increases the efficiency of the operation. The basis for this efficiency is that
putForExternalRead calls of this type are used because the client can retrieve the required data from a persistent store if the data cannot be found in memory. If the client encounters a cache miss, it retries the operation.
1.2.2. Configure Per-Invocation Flags
To use per-invocation flags in Red Hat JBoss Data Grid, add the required flags to the advanced cache via the
withFlags() method call.
Example 1.2. Configuring Per-Invocation Flags
Cache cache = ...
cache.getAdvancedCache()
.withFlags(Flag.SKIP_CACHE_STORE, Flag.CACHE_MODE_LOCAL)
.put("local", "only");Note
The called flags only remain active for the duration of the cache operation. To use the same flags in multiple invocations within the same transaction, use the
withFlags() method for each invocation. If the cache operation must be replicated onto another node, the flags are also carried over to the remote nodes.
1.2.3. Per-Invocation Flags Example
In a use case for Red Hat JBoss Data Grid, where a write operation, such as
put(), must not return the previous value, the IGNORE_RETURN_VALUES flag is used. This flag prevents a remote lookup (to get the previous value) in a distributed environment, which in turn prevents the retrieval of the undesired, potential, previous value. Additionally, if the cache is configured with a cache loader, this flag prevents the previous value from being loaded from its cache store.
Example 1.3. Using the IGNORE_RETURN_VALUES Flag
Cache cache = ...
cache.getAdvancedCache()
.withFlags(Flag.IGNORE_RETURN_VALUES)
.put("local", "only")1.3. The AdvancedCache Interface
Red Hat JBoss Data Grid offers an
AdvancedCache interface, geared towards extending JBoss Data Grid, in addition to its simple Cache Interface. The AdvancedCache Interface can:
- Inject custom interceptors
- Access certain internal components
- Apply flags to alter the behavior of certain cache methods
The following code snippet presents an example of how to obtain an
AdvancedCache:
AdvancedCache advancedCache = cache.getAdvancedCache();
1.3.1. Flag Usage with the AdvancedCache Interface
Flags, when applied to certain cache methods in Red Hat JBoss Data Grid, alter the behavior of the target method. Use
AdvancedCache.withFlags() to apply any number of flags to a cache invocation.
Example 1.4. Applying Flags to a Cache Invocation
advancedCache.withFlags(Flag.CACHE_MODE_LOCAL, Flag.SKIP_LOCKING)
.withFlags(Flag.FORCE_SYNCHRONOUS)
.put("hello", "world");1.3.2. Custom Interceptors and the AdvancedCache Interface
The
AdvancedCache Interface provides a mechanism that allows advanced developers to attach custom interceptors. Custom interceptors can alter the behavior of the Cache API methods and the AdvacedCache Interface can be used to attach such interceptors programmatically at run time.
1.3.3. Custom Interceptors
Custom interceptors can be added to Red Hat JBoss Data Grid declaratively or programmatically. Custom interceptors extend JBoss Data Grid by allowing it to influence or respond to cache modifications. Examples of such cache modifications are the addition, removal or updating of elements or transactions.
1.3.3.1. Custom Interceptor Design
To design a custom interceptor in Red Hat JBoss Data Grid, adhere to the following guidelines:
- A custom interceptor must extend the
CommandInterceptor. - A custom interceptor must declare a public, empty constructor to allow for instantiation.
- A custom interceptor must have JavaBean style setters defined for any property that is defined through the
propertyelement.
1.3.3.2. Adding Custom Interceptors Declaratively
Each named cache in Red Hat JBoss Data Grid has its own interceptor stack. As a result, custom interceptors can be added on a per named cache basis.
A custom interceptor can be added using XML. Use the following procedure to add custom interceptors.
Procedure 1.1. Adding Custom Interceptors
Define Custom Interceptors
All custom interceptors must extend org.jboss.cache.interceptors.base.CommandInterceptor. Use the customInterceptors method to add custom interceptors to the cache:<namedCache name="cacheWithCustomInterceptors"> <customInterceptors>
Define the Position of the New Custom Interceptor
Interceptors must have a defined position. Valid options are:FIRST- Specifies that the new interceptor is placed first in the chain.LAST- Specifies that the new interceptor is placed last in the chain.OTHER_THAN_FIRST_OR_LAST- Specifies that the new interceptor can be placed anywhere except first or last in the chain.
<namedCache name="cacheWithCustomInterceptors"> <customInterceptors> <interceptor position="FIRST" class="com.mycompany.CustomInterceptor1">Define Interceptor Properties
Define specific interceptor properties.<namedCache name="cacheWithCustomInterceptors"> <customInterceptors> <interceptor position="FIRST" class="com.mycompany.CustomInterceptor1"> <properties> <property name="attributeOne" value="value1" /> <property name="attributeTwo" value="value2" /> </properties> </interceptor>
Apply Other Custom Interceptors
In this example, the next custom interceptor is called CustomInterceptor2.<namedCache name="cacheWithCustomInterceptors"> <customInterceptors> <interceptor position="FIRST" class="com.mycompany.CustomInterceptor1"> <properties> <property name="attributeOne" value="value1" /> <property name="attributeTwo" value="value2" /> </properties> </interceptor> <interceptor position="LAST" class="com.mycompany.CustomInterceptor2"/>Define the
index,before, andafterAttributes.- The
indexidentifies the position of this interceptor in the chain, with 0 being the first position. This attribute is mutually exclusive withposition,before, andafter. - The
aftermethod places the new interceptor directly after the instance of the named interceptor specified via its fully qualified class name. This attribute is mutually exclusive withposition,before, andindex. - The
beforemethod places the new interceptor directly before the instance of the named interceptor specified via its fully qualified class name. This attribute is mutually exclusive withposition,after, andindex.
<namedCache name="cacheWithCustomInterceptors"> <customInterceptors> <interceptor position="FIRST" class="com.mycompany.CustomInterceptor1"> <properties> <property name="attributeOne" value="value1" /> <property name="attributeTwo" value="value2" /> </properties> </interceptor> <interceptor position="LAST" class="com.mycompany.CustomInterceptor2"/> <interceptor index="3" class="com.mycompany.CustomInterceptor1"/> <interceptor before="org.infinispan.interceptors.CallInterceptor" class="com.mycompany.CustomInterceptor2"/> <interceptor after="org.infinispan.interceptors.CallInterceptor" class="com.mycompany.CustomInterceptor1"/> </customInterceptors> </namedCache>
Note
This configuration is only valid for JBoss Data Grid's Library Mode.
1.3.3.3. Adding Custom Interceptors Programmatically
To add a custom interceptor programmatically in Red Hat JBoss Data Grid, first obtain a reference to the
AdvancedCache.
Example 1.5. Obtain a Reference to the AdvancedCache
CacheManager cm = getCacheManager();
Cache aCache = cm.getCache("aName");
AdvancedCache advCache = aCache.getAdvancedCache();
Then use an
addInterceptor() method to add the interceptor.
Example 1.6. Add the Interceptor
advCache.addInterceptor(new MyInterceptor(), 0);
1.3.4. Other Management Tools and Operations
Managing Red Hat JBoss Data Grid instances requires exposing significant amounts of relevant statistical information. This information allows administrators to get a clear view of each JBoss Data Grid node's state. A single installation can comprise of tens or hundreds of JBoss Data Grid nodes and it is important to provide this information in a clear and concise manner. JBoss Operations Network is one example of a tool that provides runtime visibility. Other tools, such as JConsole can be used where JMX is enabled.
1.3.4.1. Accessing Data via URLs
Caches that have been configured with a REST interface have access to Red Hat JBoss Data Grid using RESTful HTTP access.
The RESTful service only requires a HTTP client library, eliminating the need for tightly coupled client libraries and bindings.
HTTP
put() and post() methods place data in the cache, and the URL used determines the cache name and key(s) used. The data is the value placed into the cache, and is placed in the body of the request.
A Content-Type header must be set for these methods.
GET and HEAD methods are used for data retrieval while other headers control cache settings and behavior.
Note
It is not possible to have conflicting server modules interact with the data grid. Caches must be configured with a compatible interface in order to have access to JBoss Data Grid.
1.3.4.2. Limitations of Map Methods
Specific Map methods, such as
size(), values(), keySet() and entrySet(), can be used with certain limitations with Red Hat JBoss Data Grid as they are unreliable. These methods do not acquire locks (global or local) and concurrent modification, additions and removals are excluded from consideration in these calls. Furthermore, the listed methods are only operational on the local cache and do not provide a global view of state.
If the listed methods acted globally, it would result in a significant impact on performance and would produce a scalability bottleneck. As a result, it is recommended that these methods are used for informational and debugging purposes only.
Performance Concerns
From Red Hat JBoss Data Grid 6.3 onwards, the map methods size(), values(), keySet(), and entrySet() include entries in the cache loader by default whereas previously these methods only included the local data container. The underlying cache loader directly affects the performance of these commands. As an example, when using a database, these methods run a complete scan of the table where data is stored which can result in slower processing. Use Cache.getAdvancedCache().withFlags(Flag.SKIP_CACHE_LOAD).values() to maintain the old behavior and not loading from the cache loader which would avoid the slower performance.
Chapter 2. The Batching API
The Batching API is used when the Red Hat JBoss Data Grid cluster is the sole participant in a transaction. However, Java Transaction API (JTA) transactions (which use the Transaction Manager) are used when multiple systems are participants in the transaction.
Note
The Batching API cannot be used in JBoss Data Grid's Remote Client-Server mode.
2.1. About Java Transaction API
Red Hat JBoss Data Grid supports configuring, use of, and participation in Java Transaction API (JTA) compliant transactions.
JBoss Data Grid does the following for each cache operation:
- First, it retrieves the transactions currently associated with the thread.
- If not already done, it registers an
XAResourcewith the transaction manager to receive notifications when a transaction is committed or rolled back.
2.2. Batching and the Java Transaction API (JTA)
In Red Hat JBoss Data Grid, the batching functionality initiates a JTA transaction in the back end, causing all invocations within the scope to be associated with it. For this purpose, the batching functionality uses a simple Transaction Manager implementation at the back end. As a result, the following behavior is observed:
- Locks acquired during an invocation are retained until the transaction commits or rolls back.
- All changes are replicated in a batch on all nodes in the cluster as part of the transaction commit process. Ensuring that multiple changes occur within the single transaction, the replication traffic remains lower and improves performance.
- When using synchronous replication or invalidation, a replication or invalidation failure causes the transaction to roll back.
- When a cache is transactional and a cache loader is present, the cache loader is not enlisted in the cache's transaction. This results in potential inconsistencies at the cache loader level when the transaction applies the in-memory state but (partially) fails to apply the changes to the store.
- All configurations related to a transaction apply for batching as well.
Example 2.1. Configuring a Transaction that Applies for Batching
<transaction syncRollbackPhase="false" syncCommitPhase="false" useEagerLocking="true" eagerLockSingleNode="true" />
The configuration attributes can be used for both transactions and batching, using different values.
Note
Batching functionality and JTA transactions are only supported in JBoss Data Grid's Library Mode.
2.3. Using the Batching API
2.3.1. Enable the Batching API
Red Hat JBoss Data Grid's Batching API uses the JBoss Enterprise Application Platform syntax to enable invocation batching in your cache configuration.
Example 2.2. Enable Invocation Batching
<distributed-cache name="default" batching="true" statistics="true"> ... </distributed-cache>
In JBoss Data Grid, invocation batching is disabled by default and batching can be used without a defined Transaction Manager.
2.3.2. Configure the Batching API
To use the Batching API, enable invocation batching in the cache configuration.
XML Configuration
To configure the Batching API in the XML file:
<invocationBatching enabled="true" />
Programmatic Configuration
To configure the Batching API programmatically use:
Configuration c = new ConfigurationBuilder().invocationBatching().enable().build();
In Red Hat JBoss Data Grid, invocation batching is disabled by default and batching can be used without a defined Transaction Manager.
Note
Programmatic configurations can only be used with JBoss Data Grid's Library mode.
2.3.3. Use the Batching API
After the cache is configured to use batching, call
startBatch() and endBatch() on the cache as follows to use batching:
Cache cache = cacheManager.getCache();
Example 2.3. Without Using Batch
cache.put("key", "value");
When the
cache.put(key, value); line executes, the values are replaced immediately.
Example 2.4. Using Batch
cache.startBatch();
cache.put("k1", "value");
cache.put("k2", "value");
cache.put("k3", "value");
cache.endBatch(true);
cache.startBatch();
cache.put("k1", "value");
cache.put("k2", "value");
cache.put("k3", "value");
cache.endBatch(false);
When the line
cache.endBatch(true); executes, all modifications made since the batch started are replicated.
When the line
cache.endBatch(false); executes, changes made in the batch are discarded.
2.3.4. Batching API Usage Example
A simple use case that illustrates the Batching API usage is one that involves transferring money between two bank accounts.
Example 2.5. Batching API Usage Example
Red Hat JBoss Data Grid is used for a transaction that involves transferring money from one bank account to another. If both the source and destination bank accounts are located within JBoss Data Grid, a Batching API is used for this transaction. However, if one account is located within JBoss Data Grid and the other in a database, distributed transactions are required for the transaction.
Chapter 3. The Grouping API
The Grouping API can relocate groups of entries to a specified node or to a node selected using the hash of the group.
3.1. Grouping API Operations
Normally, Red Hat JBoss Data Grid uses the hash of a specific key to determine an entry's destination node. However, when the Grouping API is used, a hash of the group associated with the key is used instead of the hash of the key to determine the destination node.
Each node can use an algorithm to determine the owner of each key. This removes the need to pass metadata (and metadata updates) about the location of entries between nodes. This approach is beneficial because:
- Every node can determine which node owns a particular key without expensive metadata updates across nodes.
- Redundancy is improved because ownership information does not need to be replicated if a node fails.
When using the Grouping API, each node must be able to calculate the owner of an entry. As a result, the group cannot be specified manually and must be either:
- Intrinsic to the entry, which means it was generated by the key class.
- Extrinsic to the entry, which means it was generated by an external function.
3.2. Grouping API Use Case
This feature allows logically related data to be stored on a single node. For example, if the cache contains user information, the information for all users in a single location can be stored on a single node.
The benefit of this approach is that when seeking specific (logically related) data, the Distributed Executor task is directed to run only on the relevant node rather than across all nodes in the cluster. Such directed operations result in optimized performance.
Example 3.1. Grouping API Example
Acme, Inc. is a home appliance company with over one hundred offices worldwide. Some offices house employees from various departments, while certain locations are occupied exclusively by the employees of one or two departments. The Human Resources (HR) department has employees in Bangkok, London, Chicago, Nice and Venice.
Acme, Inc. uses Red Hat JBoss Data Grid's Grouping API to ensure that all the employee records for the HR department are moved to a single node (Node AB) in the cache. As a result, when attempting to retrieve a record for a HR employee, the
DistributedExecutor only checks node AB and quickly and easily retrieves the required employee records.
Storing related entries on a single node as illustrated optimizes the data access and prevents time and resource wastage by seeking information on a single node (or a small subset of nodes) instead of all the nodes in the cluster.
3.3. Configure the Grouping API
Use the following steps to configure the Grouping API:
- Enable groups using either the declarative or programmatic method.
- Specify either an intrinsic or extrinsic group. For more information about these group types, see Section 3.1, “Grouping API Operations”
- Register all specified groupers.
3.3.1. Enable Groups
The first step to set up the Grouping API is to enable groups. In Red Hat JBoss Data Grid, groups are enabled declaratively or programmatically as follows:
Example 3.2. Declaratively Enable Groups
Use the following configuration to enable groups using XML:
<clustering>
<hash>
<groups enabled="true" />
</hash>
</clustering>Example 3.3. Programmatically Enable Groups
Use the following to enable groups programmatically:
Configuration c = new ConfigurationBuilder().clustering().hash().groups().enabled().build();
3.3.2. Specify an Intrinsic Group
Use an intrinsic group with the Grouping API if:
- the key class definition can be altered, that is if it is not part of an unmodifiable library.
- if the key class is not concerned with the determination of a key/value pair group.
Use the
@Group annotation in the relevant method to specify an intrinsic group. The group must always be a String, as illustrated in the example:
Example 3.4. Specifying an Intrinsic Group Example
class User {
...
String office;
...
public int hashCode()) {
// Defines the hash for the key, normally used to determine location
...
}
// Override the location by specifying a group, all keys in the same
// group end up with the same owner
@Group
String getOffice() {
return office;
}
}3.3.3. Specify an Extrinsic Group
Specify an extrinsic group for the Grouping API if:
- the key class definition cannot be altered, that is if it is part of an unmodifiable library.
- if the key class is concerned with the determination of a key/value pair group.
An extrinsic group is specified using an implementation of the
Grouper interface. This interface uses the computeGroup method to return the group.
In the process of specifying an extrinsic group, the
Grouper interface acts as an interceptor by passing the computed value to computeGroup. If the @Group annotation is used, the group using it is passed to the first Grouper. As a result, using an intrinsic group provides even greater control.
Example 3.5. Specifying an Extrinsic Group Example
The following is an example that consists of a simple
Grouper that uses the key class to extract the group from a key using a pattern. Any group information specified on the key class is ignored in such a situation.
public class KXGrouper implements Grouper<String> {
// A pattern that can extract from a "kX" (e.g. k1, k2) style key
// The pattern requires a String key, of length 2, where the first character is
// "k" and the second character is a digit. We take that digit, and perform
// modular arithmetic on it to assign it to group "1" or group "2".
private static Pattern kPattern = Pattern.compile("(^k)(\\d)$");
public String computeGroup(String key, String group) {
Matcher matcher = kPattern.matcher(key);
if (matcher.matches()) {
String g = Integer.parseInt(matcher.group(2)) % 2 + "";
return g;
} else
return null;
}
public Class<String> getKeyType() {
return String.class;
}
}3.3.4. Register Groupers
After creation, each grouper must be registered to be used.
Example 3.6. Declaratively Register a Grouper
<clustering>
<hash>
<groups enabled="true">
<grouper class="com.acme.KXGrouper" />
</groups>
</hash>
</clustering>Example 3.7. Programmatically Register a Grouper
Configuration c = new ConfigurationBuilder().clustering().hash().groups().addGrouper(new KXGrouper()).enabled().build();
Chapter 4. The Persistence SPI
In Red Hat JBoss Data Grid, persistence can configure external (persistent) storage engines. These storage engines complement JBoss Data Grid's default in-memory storage.
Persistent external storage provides several benefits:
- Memory is volatile and a cache store can increase the life span of the information in the cache, which results in improved durability.
- Using persistent external stores as a caching layer between an application and a custom storage engine provides improved Write-Through functionality.
- Using a combination of eviction and passivation, only the frequently required information is stored in-memory and other data is stored in the external storage.
4.1. Persistence SPI Benefits
The Red Hat JBoss Data Grid implementation of the Persistence SPI offers the following benefits:
- Alignment with JSR-107 (http://jcp.org/en/jsr/detail?id=107). JBoss Data Grid's
CacheWriterandCacheLoaderinterfaces are similar to the JSR-107 writer and reader. As a result, alignment with JSR-107 provides improved portability for stores across JCache-compliant vendors. - Simplified transaction integration. JBoss Data Grid handles locking automatically and so implementations do not have to coordinate concurrent access to the store. Depending on the locking mode, concurrent writes on the same key may not occur. However, implementors expect operations on the store to originate from multiple threads and add the implementation code accordingly.
- Reduced serialization, resulting in reduced CPU usage. The new SPI exposes stored entries in a serialized format. If an entry is fetched from persistent storage to be sent remotely, it does not need to be serialized (when reading from the store) and then serialized again (when writing to the wire). Instead, the entry is written to the wire in the serialized format as fetched from the storage.
4.2. Programmatically Configure the Persistence SPI
The following is a sample programmatic configuration for a Single File Store using the Persistence SPI:
Example 4.1. Configure the Single File Store via the Persistence SPI
ConfigurationBuilder builder = new ConfigurationBuilder();
builder.persistence()
.passivation(false)
.addSingleFileStore()
.preload(true)
.shared(false)
.fetchPersistentState(true)
.ignoreModifications(false)
.purgeOnStartup(false)
.location(System.getProperty("java.io.tmpdir"))
.async()
.enabled(true)
.threadPoolSize(5)
.singleton()
.enabled(true)
.pushStateWhenCoordinator(true)
.pushStateTimeout(20000);Note
Programmatic configurations can only be used with Red Hat JBoss Data Grid's Library mode.
Chapter 5. The ConfigurationBuilder API
The ConfigurationBuilder API is a programmatic configuration API in Red Hat JBoss Data Grid.
The ConfigurationBuilder API is designed to assist with:
- Chain coding of configuration options in order to make the coding process more efficient
- Improve the readability of the configuration
In JBoss Data Grid, the ConfigurationBuilder API is also used to enable CacheLoaders and configure both global and cache level operations.
5.1. Using the ConfigurationBuilder API
5.1.1. Programmatically Create a CacheManager and Replicated Cache
Programmatic configuration in Red Hat JBoss Data Grid almost exclusively involves the ConfigurationBuilder API and the CacheManager. The following is an example of a programmatic CacheManager configuration:
Example 5.1. Configure the CacheManager Programmatically
EmbeddedCacheManager manager = new DefaultCacheManager("my-config-file.xml");
Cache defaultCache = manager.getCache();
Configuration c = new ConfigurationBuilder().clustering().cacheMode(CacheMode.REPL_SYNC)
.build();
String newCacheName = "repl";
manager.defineConfiguration(newCacheName, c);
Cache<String, String> cache = manager.getCache(newCacheName);
An explanation of each line of the provided configuration is as follows:
Procedure 5.1. Steps for Programmatic Configuration in JBoss Data Grid
- Create a CacheManager as a starting point in an XML file. If required, this CacheManager can be programmed in runtime to the specification that meets the requirements of the use case. The following is an example of how to create a CacheManager:
EmbeddedCacheManager manager = new DefaultCacheManager("my-config-file.xml"); Cache defaultCache = manager.getCache(); - Create a new synchronously replicated cache programmatically.
- Create a new configuration object instance using the ConfigurationBuilder helper object:
Configuration c = new ConfigurationBuilder().clustering().cacheMode(CacheMode.REPL_SYNC) .build();
In the first line of the configuration, a new cache configuration object (namedc) is created using theConfigurationBuilder. Configurationcis assigned the default values for all cache configuration options except the cache mode, which is overridden and set to synchronous replication (REPL_SYNC). - Set the cache mode to synchronous replication:
String newCacheName = "repl";
In the second line of the configuration, a new variable (of typeString) is created and assigned the valuerepl. - Define or register the configuration with a manager:
manager.defineConfiguration(newCacheName, c);
In the third line of the configuration, the cache manager is used to define a named cache configuration for itself. This named cache configuration is calledrepland its configuration is based on the configuration provided for cache configurationcin the first line. Cache<String, String> cache = manager.getCache(newCacheName);
In the fourth line of the configuration, the cache manager is used to obtain a reference to the unique instance of thereplthat is held by the cache manager. This cache instance is now ready to be used to perform operations to store and retrieve data.
Note
Programmatic configurations can only be used with JBoss Data Grid's Library mode.
5.1.2. Create a Customized Cache Using the Default Named Cache
The default cache configuration (or any customized configuration) can serve as a starting point to create a new cache.
As an example, if the
infinispan-config-file.xml specifies the configuration for a replicated cache as a default and a distributed cache with a customized lifespan value is required. The required distributed cache must retain all aspects of the default cache specified in the infinispan-config-file.xml file except the mentioned aspects.
Example 5.2. Configuring Customized Default Cache
EmbeddedCacheManager manager = new DefaultCacheManager("infinispan-config-file.xml");
Configuration dcc = cacheManager.getDefaultCacheConfiguration();
Configuration c = new ConfigurationBuilder().read(dcc).clustering()
.cacheMode(CacheMode.DIST_SYNC).l1().lifespan(60000L).enable()
.build();
manager.defineConfiguration(newCacheName, c);
Cache<String, String> cache = manager.getCache(newCacheName);
An explanation of the provided configuration is as follows:
Procedure 5.2. Customize the Default Cache
- Read an instance of a default Configuration object to get the default configuration:
EmbeddedCacheManager manager = new DefaultCacheManager("infinispan-config-file.xml"); Configuration dcc = cacheManager.getDefaultCacheConfiguration(); - Use the ConfigurationBuilder to construct and modify the cache mode and L1 cache lifespan on a new configuration object:
Configuration c = new ConfigurationBuilder().read(dcc).clustering() .cacheMode(CacheMode.DIST_SYNC).l1().lifespan(60000L).enable() .build();
- Register/define your cache configuration with a cache manager, where cacheName is name of cache specified in
infinispan-config-file.xml:manager.defineConfiguration(newCacheName, c);
- Get default cache with custom configuration changes:
Cache<String, String> cache = manager.getCache(newCacheName);
5.1.3. Create a Customized Cache Using a Non-Default Named Cache
A situation can arise where a new customized cache must be created using a named cache that is not the default. The steps to accomplish this are similar to those used when using the default named cache for this purpose.
The difference in approach is due to taking a named cache called
replicatedCache as the base instead of the default cache.
Example 5.3. Creating a Customized Cache Using a Non-Default Named Cache
EmbeddedCacheManager manager = new DefaultCacheManager("infinispan-config-file.xml");
Configuration rc = cacheManager.getCacheConfiguration("replicatedCache");
Configuration c = new ConfigurationBuilder().read(rc).clustering()
.cacheMode(CacheMode.DIST_SYNC).l1().lifespan(60000L).enable()
.build();
manager.defineConfiguration(newCacheName, c);
Cache<String, String> cache = manager.getCache(newCacheName);
An explanation of the provided example is as follows:
Procedure 5.3. Create a Customized Cache Using a Non-Default Named Cache
- Read the
replicatedCacheto get the default configuration:EmbeddedCacheManager manager = new DefaultCacheManager("infinispan-config-file.xml"); Configuration rc = cacheManager.getCacheConfiguration("replicatedCache"); - Use the ConfigurationBuilder to construct and modify the desired configuration on a new configuration object:
Configuration c = new ConfigurationBuilder().read(rc).clustering() .cacheMode(CacheMode.DIST_SYNC).l1().lifespan(60000L).enable() .build();
- Register/define your cache configuration with a cache manager where newCacheName is the name of cache specified in
infinispan-config-file.xmlmanager.defineConfiguration(newCacheName, c);
- Get a default cache with custom configuration changes:
Cache<String, String> cache = manager.getCache(newCacheName);
5.1.4. Using the Configuration Builder to Create Caches Programmatically
As an alternative to using an xml file with default cache values to create a new cache, use the ConfigurationBuilder API to create a new cache without any XML files. The ConfigurationBuilder API is intended to provide ease of use when creating chained code for configuration options.
The following new configuration is valid for global and cache level configuration. GlobalConfiguration objects are constructed using GlobalConfigurationBuilder while Configuration objects are built using ConfigurationBuilder.
5.1.5. Global Configuration Examples
5.1.5.1. Globally Configure the Transport Layer
A commonly used configuration option is to configure the transport layer. This informs Red Hat JBoss Data Grid how a node will discover other nodes:
Example 5.4. Configuring the Transport Layer
GlobalConfiguration globalConfig = new GlobalConfigurationBuilder() .globalJmxStatistics().enable() .build();
5.1.5.2. Globally Configure the Cache Manager Name
The following sample configuration allows you to use options from the global JMX statistics level to configure the name for a cache manager. This name distinguishes a particular cache manager from other cache managers on the same system.
Example 5.5. Configuring the Cache Manager Name
GlobalConfiguration globalConfig = new GlobalConfigurationBuilder()
.globalJmxStatistics()
.cacheManagerName("SalesCacheManager")
.mBeanServerLookup(new JBossMBeanServerLookup())
.enable()
.build();5.1.5.3. Globally Customize Thread Pool Executors
Some Red Hat JBoss Data Grid features are powered by a group of thread pool executors. These executors can be customized at the global level as follows:
Example 5.6. Customize Thread Pool Executors
GlobalConfiguration globalConfig = new GlobalConfigurationBuilder()
.replicationQueueScheduledExecutor()
.factory(new DefaultScheduledExecutorFactory())
.addProperty("threadNamePrefix", "RQThread")
.build();5.1.6. Cache Level Configuration Examples
5.1.6.1. Cache Level Configuration for the Cluster Mode
The following configuration allows the use of options such as the cluster mode for the cache at the cache level rather than globally:
Example 5.7. Configure Cluster Mode at Cache Level
Configuration config = new ConfigurationBuilder()
.clustering()
.cacheMode(CacheMode.DIST_SYNC)
.sync()
.l1().lifespan(25000L).enable()
.hash().numOwners(3)
.build();5.1.6.2. Cache Level Eviction and Expiration Configuration
Use the following configuration to configure expiration or eviction options for a cache at the cache level:
Example 5.8. Configuring Expiration and Eviction at the Cache Level
Configuration config = new ConfigurationBuilder()
.eviction()
.maxEntries(20000).strategy(EvictionStrategy.LIRS).expiration()
.wakeUpInterval(5000L)
.maxIdle(120000L)
.build();5.1.6.3. Cache Level Configuration for JTA Transactions
To interact with a cache for JTA transaction configuration, configure the transaction layer and optionally customize the locking settings. For transactional caches, it is recommended to enable transaction recovery to deal with unfinished transactions. Additionally, it is recommended that JMX management and statistics gathering is also enabled.
Example 5.9. Configuring JTA Transactions at Cache Level
Configuration config = new ConfigurationBuilder()
.locking()
.concurrencyLevel(10000).isolationLevel(IsolationLevel.REPEATABLE_READ)
.lockAcquisitionTimeout(12000L).useLockStriping(false).writeSkewCheck(true)
.transaction()
.transactionManagerLookup(new GenericTransactionManagerLookup())
.recovery().enable()
.jmxStatistics().enable()
.build();5.1.6.4. Cache Level Configuration Using Chained Persistent Stores
The following configuration can be used to configure one or more chained persistent stores at the cache level:
Example 5.10. Configuring Chained Persistent Stores at Cache Level
Configuration config = new ConfigurationBuilder()
.persistence()
.passivation(false)
.addSingleFileStore().shared(false).preload(false).location("/tmp").async().enable().threadPoolSize(20).build();5.1.6.5. Cache Level Configuration for Advanced Externalizers
An advanced option such as a cache level configuration for advanced externalizers can also be configured programmatically as follows:
Example 5.11. Configuring Advanced Externalizers at Cache Level
GlobalConfiguration globalConfig = new GlobalConfigurationBuilder()
.serialization()
.addAdvancedExternalizer(new PersonExternalizer())
.addAdvancedExternalizer(999, new AddressExternalizer())
.build();Chapter 6. The Externalizable API
An
Externalizer is a class that can:
- Marshall a given object type to a byte array.
- Unmarshall the contents of a byte array into an instance of the object type.
Externalizers are used by Red Hat JBoss Data Grid and allow users to specify how their object types are serialized. The marshalling infrastructure used in JBoss Data Grid builds upon JBoss Marshalling and provides efficient payload delivery and allows the stream to be cached. The stream caching allows data to be accessed multiple times, whereas normally a stream can only be read once.
The Externalizable interface uses and extends serialization. This interface is used to control serialization and deserialization in JBoss Data Grid.
6.1. Customize Externalizers
As a default in Red Hat JBoss Data Grid, all objects used in a distributed or replicated cache must be serilizable. The default Java serialization mechanism can result in network and performance inefficiency. Additional concerns include serialization versioning and backwards compatibility.
For enhanced throughput, performance or to enforce specific object compatibility, use a customized externalizer. Customized externalizers for JBoss Data Grid can be used in one of two ways:
- Use an Externalizable Interface. For details, see the Red Hat JBoss Data Grid Developer Guide's The Externalizable API chapter.
- Use an advanced externalizer.
6.2. Annotating Objects for Marshalling Using @SerializeWith
Objects can be marshalled by providing an Externalizer implementation for the type that needs to be marshalled or unmarshalled, then annotating the marshalled type class with
@SerializeWith indicating the Externalizer class to use.
Example 6.1. Using the @SerializeWith Annotation
import org.infinispan.commons.marshall.Externalizer;
import org.infinispan.commons.marshall.SerializeWith;
@SerializeWith(Person.PersonExternalizer.class)
public class Person {
final String name;
final int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public static class PersonExternalizer implements Externalizer<Person> {
@Override
public void writeObject(ObjectOutput output, Person person)
throws IOException {
output.writeObject(person.name);
output.writeInt(person.age);
}
@Override
public Person readObject(ObjectInput input)
throws IOException, ClassNotFoundException {
return new Person((String) input.readObject(), input.readInt());
}
}
}
In the provided example, the object has been defined as marshallable due to the
@SerializeWith annotation. JBoss Marshalling will therefore marshall the object using the Externalizer class passed.
This method of defining externalizers is user friendly, however it has the following disadvantages:
- The payload sizes generated using this method are not the most efficient. This is due to some constraints in the model, such as support for different versions of the same class, or the need to marshall the Externalizer class.
- This model requires the marshalled class to be annotated with
@SerializeWith, however an Externalizer may need to be provided for a class for which source code is not available, or for any other constraints, it cannot be modified. - Annotations used in this model may be limiting for framework developers or service providers that attempt to abstract lower level details, such as the marshalling layer, away from the user.
Advanced Externalizers are available for users affected by these disadvantages.
Note
To make Externalizer implementations easier to code and more typesafe, define type <t> as the type of object that is being marshalled or unmarshalled.
6.3. Using an Advanced Externalizer
Using a customized advanced externalizer helps optimize performance in Red Hat JBoss Data Grid.
- Define and implement the
readObject()andwriteObject()methods. - Link externalizers with marshaller classes.
- Register the advanced externalizer.
6.3.1. Implement the Methods
To use advanced externalizers, define and implement the
readObject() and writeObject() methods. The following is a sample definition:
Example 6.2. Define and Implement the Methods
import org.infinispan.commons.marshall.AdvancedExternalizer;
public class Person {
final String name;
final int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public static class PersonExternalizer implements AdvancedExternalizer<Person> {
@Override
public void writeObject(ObjectOutput output, Person person)
throws IOException {
output.writeObject(person.name);
output.writeInt(person.age);
}
@Override
public Person readObject(ObjectInput input)
throws IOException, ClassNotFoundException {
return new Person((String) input.readObject(), input.readInt());
}
@Override
public Set<Class<? extends Person>> getTypeClasses() {
return Util.<Class<? extends Person>>asSet(Person.class);
}
@Override
public Integer getId() {
return 2345;
}
}
}Note
This method does not require annotated user classes. As a result, this method is valid for classes where the source code is not available or cannot be modified.
6.3.2. Link Externalizers with Marshaller Classes
Use an implementation of
getTypeClasses() to discover the classes that this externalizer can marshall and to link the readObject() and writeObject() classes.
The following is a sample implementation:
import org.infinispan.util.Util;
...
@Override
public Set<Class<? extends ReplicableCommand>> getTypeClasses() {
return Util.asSet(LockControlCommand.class, GetKeyValueCommand.class,
ClusteredGetCommand.class, MultipleRpcCommand.class,
SingleRpcCommand.class, CommitCommand.class,
PrepareCommand.class, RollbackCommand.class,
ClearCommand.class, EvictCommand.class,
InvalidateCommand.class, InvalidateL1Command.class,
PutKeyValueCommand.class, PutMapCommand.class,
RemoveCommand.class, ReplaceCommand.class);
}
In the provided sample, the
ReplicableCommandExternalizer indicates that it can externalize several command types. This sample marshalls all commands that extend the ReplicableCommand interface but the framework only supports class equality comparison so it is not possible to indicate that the classes marshalled are all children of a particular class or interface.
In some cases, the class to be externalized is private and therefore the class instance is not accessible. In such a situation, look up the class with the provided fully qualified class name and pass it back. An example of this is as follows:
@Override
public Set<Class<? extends List>> getTypeClasses() {
return Util.<Class<? extends List>>asSet(
Util.<List>loadClass("java.util.Collections$SingletonList", null));
}6.3.3. Register the Advanced Externalizer (Declaratively)
After the advanced externalizer is set up, register it for use with Red Hat JBoss Data Grid. This registration is done declaratively (via XML) as follows:
Procedure 6.1. Register the Advanced Externalizer
- Add the
globalelement to theinfinispanelement:<infinispan> <global /> </infinispan>
- Add the
serializationelement to theglobalelement as follows:<infinispan> <global> <serialization /> </global> </infinispan> - Add the
advancedExternalizerselement to add information about the new advanced externalizer as follows:<infinispan> <global> <serialization> <advancedExternalizers /> </serialization> </global> </infinispan> - Define the externalizer class using the
externalizerClassattribute as follows:<infinispan> <global> <serialization> <advancedExternalizers> <advancedExternalizer externalizerClass="org.infinispan.marshall.AdvancedExternalizerTest$IdViaAnnotationObj$Externalizer"/> </advancedExternalizers> </serialization> </global> </infinispan>Replace the $IdViaAnnotationObj and $AdvancedExternalizer values as required.
6.3.4. Register the Advanced Externalizer (Programmatically)
After the advanced externalizer is set up, register it for use with Red Hat JBoss Data Grid. This registration is done programmatically as follows:
Example 6.3. Registering the Advanced Externalizer Programmatically
GlobalConfigurationBuilder builder = ... builder.serialization() .addAdvancedExternalizer(new Person.PersonExternalizer());
Enter the desired information for the GlobalConfigurationBuilder in the first line.
6.3.5. Register Multiple Externalizers
Alternatively, register multiple advanced externalizers because
GlobalConfiguration.addExternalizer() accepts varargs. Before registering the new externalizers, ensure that their IDs are already defined using the @Marshalls annotation.
Example 6.4. Registering Multiple Externalizers
builder.serialization()
.addAdvancedExternalizer(new Person.PersonExternalizer(),
new Address.AddressExternalizer());6.4. Custom Externalizer ID Values
Advanced externalizers can be assigned custom IDs if desired. Some ID ranges are reserved for other modules or frameworks and must be avoided:
Table 6.1. Reserved Externalizer ID Ranges
| ID Range | Reserved For |
|---|---|
| 1000-1099 | The Infinispan Tree Module |
| 1100-1199 | Red Hat JBoss Data Grid Server modules |
| 1200-1299 | Hibernate Infinispan Second Level Cache |
| 1300-1399 | JBoss Data Grid Lucene Directory |
| 1400-1499 | Hibernate OGM |
| 1500-1599 | Hibernate Search |
| 1600-1699 | Infinispan Query Module |
| 1700-1799 | Infinispan Remote Query Module |
6.4.1. Customize the Externalizer ID (Declaratively)
Customize the advanced externalizer ID declaratively (via XML) as follows:
Procedure 6.2. Customizing the Externalizer ID (Declaratively)
- Add the
globalelement to theinfinispanelement:<infinispan> <global /> </infinispan>
- Add the
serializationelement to theglobalelement as follows:<infinispan> <global> <serialization /> </global> </infinispan> - Add the
advancedExternalizerelement to add information about the new advanced externalizer as follows:<infinispan> <global> <serialization> <advancedExternalizer /> </serialization> </global> </infinispan> - Define the externalizer ID using the
idattribute as follows:<infinispan> <global> <serialization> <advancedExternalizers> <advancedExternalizer id="$ID" /> </advancedExternalizers> </serialization> </global> </infinispan>Ensure that the selected ID is not from the range of IDs reserved for other modules. - Define the externalizer class using the
externalizerClassattribute as follows:<infinispan> <global> <serialization> <advancedExternalizers> <advancedExternalizer id="$ID" externalizerClass="org.infinispan.marshall.AdvancedExternalizerTest$IdViaConfigObj$Externalizer"/> </advancedExternalizers> </serialization> </global> </infinispan>Replace the $IdViaAnnotationObj and $AdvancedExternalizer values as required.
6.4.2. Customize the Externalizer ID (Programmatically)
Use the following configuration to programmatically assign a specific ID to the externalizer:
Example 6.5. Assign an ID to the Externalizer
GlobalConfiguration globalConfiguration = new GlobalConfigurationBuilder()
.serialization()
.addAdvancedExternalizer($ID, new Person.PersonExternalizer())
.build();
Replace the $ID with the desired ID.
Chapter 7. The Notification/Listener API
Red Hat JBoss Data Grid provides a listener API that provides notifications for events as they occur. Clients can choose to register with the listener API for relevant notifications. This annotation-driven API operates on cache-level events and cache manager-level events.
7.1. Listener Example
The following example defines a listener in Red Hat JBoss Data Grid that prints some information each time a new entry is added to the cache:
Example 7.1. Configuring a Listener
@Listener
public class PrintWhenAdded {
@CacheEntryCreated
public void print(CacheEntryCreatedEvent event) {
System.out.println("New entry " + event.getKey() + " created in the cache");
}
}7.2. Cache Entry Modified Listener Configuration
In a cache entry modified listener event, The
getValue() method's behavior is specific to whether the callback is triggered before or after the actual operation has been performed. For example, if event.isPre() is true, then event.getValue() would return the old value, prior to modification. If event.isPre() is false, then event.getValue() would return new value. If the event is creating and inserting a new entry, the old value would be null. For more information about isPre(), see the Red Hat JBoss Data Grid API Documentation's listing for the org.infinispan.notifications.cachelistener.event package.
Listeners can only be configured programmatically by using the methods exposed by the Listenable and FilteringListenable interfaces (which the Cache object implements).
7.3. Listener Notifications
Each cache event triggers a notification that is dispatched to listeners. A listener is a simple POJO annotated with
@Listener. A Listenable is an interface that denotes that the implementation can have listeners attached to it. Each listener is registered using methods defined in the Listenable.
A listener can be attached to both the cache and Cache Manager to allow them to receive cache-level or cache manager-level notifications.
7.3.1. About Cache-level Notifications
In Red Hat JBoss Data Grid, cache-level events occur on a per-cache basis, and are global and cluster-wide. Examples of cache-level events include the addition, removal and modification of entries, which trigger notifications to listeners registered on the relevant cache.
7.3.2. Cache Manager-level Notifications
Examples of events that occur in Red Hat JBoss Data Grid at the cache manager-level are:
- Nodes joining or leaving a cluster;
- The starting and stopping of caches
Cache manager-level events are located globally and used cluster-wide, but are restricted to events within caches created by a single cache manager.
7.3.3. About Synchronous and Asynchronous Notifications
By default, notifications in Red Hat JBoss Data Grid are dispatched in the same thread that generates the event. Therefore the listener must be written in a way that does not block or prevent the thread's progression.
Alternatively, the listener can be annotated as asynchronous, which dispatches notifications in a separate thread and prevents blocking the operations of the original thread.
Annotate listeners using the following:
@Listener (sync = false)
public class MyAsyncListener { .... }
Use the
<asyncListenerExecutor/> element in the configuration file to tune the thread pool that is used to dispatch asynchronous notifications.
7.4. NotifyingFutures
Methods in Red Hat JBoss Data Grid do not return Java Development Kit (JDK)
Futures, but a sub-interface known as a NotifyingFuture. Unlike a JDK Future, a listener can be attached to a NotifyingFuture to notify the user about a completed future.
Note
NotifyingFutures are only available in JBoss Data Grid Library mode.
7.4.1. NotifyingFutures Example
The following is an example depicting how to use
NotifyingFutures in Red Hat JBoss Data Grid:
Example 7.2. Configuring NotifyingFutures
FutureListener futureListener = new FutureListener() {
public void futureDone(Future future) {
try {
future.get();
} catch (Exception e) {
// Future did not complete successfully
System.out.println("Help!");
}
}
};
cache.putAsync("key", "value").attachListener(futureListener);Part II. Securing Data in Red Hat JBoss Data Grid
In Red Hat JBoss Data Grid, data security can be implemented in the following ways:
Role-based Access Control
JBoss Data Grid features role-based access control for operations on designated secured caches. Roles can be assigned to users who access your application, with roles mapped to permissions for cache and cache-manager operations. Only authenticated users are able to perform the operations that are authorized for their role.
In Library mode, data is secured via role-based access control for CacheManagers and Caches, with authentication delegated to the container or application. In Remote Client-Server mode, JBoss Data Grid is secured by passing identity tokens from the Hot Rod client to the server, and role-based access control of Caches and CacheManagers.
Node Authentication and Authorization
Node-level security requires new nodes or merging partitions to authenticate before joining a cluster. Only authenticated nodes that are authorized to join the cluster are permitted to do so. This provides data protection by preventing authorized servers from storing your data.
Encrypted Communications Within the Cluster
JBoss Data Grid increases data security by supporting encrypted communications between the nodes in a cluster by using a user-specified cryptography algorithm, as supported by Java Cryptography Architecture (JCA).
JBoss Data Grid also provides audit logging for operations, and the ability to encrypt communication between the Hot Rod Client and Server using Transport Layer Security (TLS/SSL).
Chapter 8. Red Hat JBoss Data Grid Security: Authorization and Authentication
8.1. Red Hat JBoss Data Grid Security: Authorization and Authentication
Red Hat JBoss Data Grid is able to perform authorization on CacheManagers and Caches. JBoss Data Grid authorization is built on standard security features available in a JDK, such as JAAS and the SecurityManager.
If an application attempts to interact with a secured CacheManager and Cache, it must provide an identity which JBoss Data Grid's security layer can validate against a set of required roles and permissions. Once validated, the client is issued a token for subsequent operations. Where access is denied, an exception indicating a security violation is thrown.
When a cache has been configured for with authorization, retrieving it returns an instance of
SecureCache. SecureCache is a simple wrapper around a cache, which checks whether the "current user" has the permissions required to perform an operation. The "current user" is a Subject associated with the AccessControlContext.
JBoss Data Grid maps Principals names to roles, which in turn, represent one or more permissions. The following diagram represents these relationships:
Figure 8.1. Roles and Permissions Mapping
8.2. Permissions
Access to a CacheManager or a Cache is controlled using a set of required permissions. Permissions control the type of action that is performed on the CacheManager or Cache, rather than the type of data being manipulated. Some of these permissions can apply to specifically name entities, such as a named cache. Different types of permissions are available depending on the entity.
Table 8.1. CacheManager Permissions
| Permission | Function | Description |
|---|---|---|
| CONFIGURATION | defineConfiguration | Whether a new cache configuration can be defined. |
| LISTEN | addListener | Whether listeners can be registered against a cache manager. |
| LIFECYCLE | stop, start | Whether the cache manager can be stopped or started respectively. |
| ALL | A convenience permission which includes all of the above. |
Table 8.2. Cache Permissions
| Permission | Function | Description |
|---|---|---|
| READ | get, contains | Whether entries can be retrieved from the cache. |
| WRITE | put, putIfAbsent, replace, remove, evict | Whether data can be written/replaced/removed/evicted from the cache. |
| EXEC | distexec, mapreduce | Whether code execution can be run against the cache. |
| LISTEN | addListener | Whether listeners can be registered against a cache. |
| BULK_READ | keySet, values, entrySet,query | Whether bulk retrieve operations can be executed. |
| BULK_WRITE | clear, putAll | Whether bulk write operations can be executed. |
| LIFECYCLE | start, stop | Whether a cache can be started / stopped. |
| ADMIN | getVersion, addInterceptor*, removeInterceptor, getInterceptorChain, getEvictionManager, getComponentRegistry, getDistributionManager, getAuthorizationManager, evict, getRpcManager, getCacheConfiguration, getCacheManager, getInvocationContextContainer, setAvailability, getDataContainer, getStats, getXAResource | Whether access to the underlying components/internal structures is allowed. |
| ALL | A convenience permission which includes all of the above. | |
| ALL_READ | Combines READ and BULK_READ. | |
| ALL_WRITE | Combines WRITE and BULK_WRITE. |
Note
Some permissions may need to be combined with others in order to be useful. For example, EXEC with READ or with WRITE.
8.3. Role Mapping
In order to convert the Principals in a Subject into a set of roles used for authorization, a
PrincipalRoleMapper must be specified in the global configuration. Red Hat JBoss Data Grid ships with three mappers, and also allows you to provide a custom mapper.
Table 8.3. Mappers
| Mapper Name | Java | XML | Description |
|---|---|---|---|
| IdentityRoleMapper | org.infinispan.security.impl.IdentityRoleMapper | <identity-role-mapper /> | Uses the Principal name as the role name. |
| CommonNameRoleMapper | org.infinispan.security.impl.CommonRoleMapper | <common-name-role-mapper /> | If the Principal name is a Distinguished Name (DN), this mapper extracts the Common Name (CN) and uses it as a role name. For example the DN cn=managers,ou=people,dc=example,dc=com will be mapped to the role managers. |
| ClusterRoleMapper | org.infinispan.security.impl.ClusterRoleMapper | <cluster-role-mapper /> | Uses the ClusterRegistry to store principal to role mappings. This allows the use of the CLI’s GRANT and DENY commands to add/remove roles to a Principal. |
| Custom Role Mapper | <custom-role-mapper class="a.b.c" /> | Supply the fully-qualified class name of an implementation of org.infinispan.security.impl.PrincipalRoleMapper |
8.4. Configuring Authentication and Role Mapping using JBoss EAP Login Modules
When using Red Hat JBoss EAP log in module for querying roles from LDAP, you must implement your own mapping of Principals to Roles, as JBoss EAP uses its own custom classes. The following example demonstrates how to map a principal obtained from JBoss EAP login module to a role. It maps user principal name to a role, performing a similar action to the
IdentityRoleMapper:
Example 8.1. Mapping a Principal from JBoss EAP's Login Module
public class SimplePrincipalGroupRoleMapper implements PrincipalRoleMapper {
@Override
public Set<String> principalToRoles(Principal principal) {
if (principal instanceof SimpleGroup) {
Enumeration<Principal> members = ((SimpleGroup) principal).members();
if (members.hasMoreElements()) {
Set<String> roles = new HashSet<String>();
while (members.hasMoreElements()) {
Principal innerPrincipal = members.nextElement();
if (innerPrincipal instanceof SimplePrincipal) {
SimplePrincipal sp = (SimplePrincipal) innerPrincipal;
roles.add(sp.getName());
}
}
return roles;
}
}
return null;
}
}Example 8.2. Example of JBoss EAP LDAP login module configuration
<security-domain name="ispn-secure" cache-type="default">
<authentication>
<login-module code="org.jboss.security.auth.spi.LdapLoginModule" flag="required">
<module-option name="java.naming.factory.initial" value="com.sun.jndi.ldap.LdapCtxFactory"/>
<module-option name="java.naming.provider.url" value="ldap://localhost:389"/>
<module-option name="java.naming.security.authentication" value="simple"/>
<module-option name="principalDNPrefix" value="uid="/>
<module-option name="principalDNSuffix" value=",ou=People,dc=infinispan,dc=org"/>
<module-option name="rolesCtxDN" value="ou=Roles,dc=infinispan,dc=org"/>
<module-option name="uidAttributeID" value="member"/>
<module-option name="matchOnUserDN" value="true"/>
<module-option name="roleAttributeID" value="cn"/>
<module-option name="roleAttributeIsDN" value="false"/>
<module-option name="searchScope" value="ONELEVEL_SCOPE"/>
</login-module>
</authentication>
</security-domain>Example 8.3. Example of JBoss EAP Login Module Configuration
<security-domain name="krb-admin" cache-type="default">
<authentication>
<login-module code="Kerberos" flag="required">
<module-option name="useKeyTab" value="true"/>
<module-option name="principal" value="admin@INFINISPAN.ORG"/>
<module-option name="keyTab" value="${basedir}/keytab/admin.keytab"/>
</login-module>
</authentication>
</security-domain>
When using GSSAPI authentication, this would typically involve using LDAP for role mapping, with JBoss EAP server authenticating itself to the LDAP server via GSSAPI. For more information on how to configure this, see the JBoss EAP Administration and Configuration Guide.
Important
For information about how to configure JBoss EAP login modules, see the JBoss EAP Administration and Configuration Guide and see the Red Hat Directory Server Administration Guide how to configure LDAP server, and specify users and their role mapping.
8.5. Configuring Red Hat JBoss Data Grid for Authorization
Authorization is configured at two levels: the cache container (CacheManager), and at the single cache.
CacheManager
The following is an example configuration for authorization at the CacheManager level:
Example 8.4. CacheManager Authorization (Declarative Configuration)
<cache-container name="local" default-cache="default">
<security>
<authorization>
<identity-role-mapper />
<role name="admin" permissions="ALL"/>
<role name="reader" permissions="READ"/>
<role name="writer" permissions="WRITE"/>
<role name="supervisor" permissions="ALL_READ ALL_WRITE"/>
</authorization>
</security>
</cache-container>
Each cache container determines:
- whether to use authorization.
- a class which will map principals to a set of roles.
- a set of named roles and the permissions they represent.
You can choose to use only a subset of the roles defined at the container level.
Roles
Roles for each cache can be defined as follows:
Example 8.5. Defining Roles
<local-cache name="secured">
<security>
<authorization roles="admin reader writer supervisor"/>
</security>
</local-cache>Programmatic CacheManager Authorization (Library Mode)
The following example shows how to set up the same authorization parameters for Library mode using programmatic configuration:
Example 8.6. CacheManager Authorization Programmatic Configuration
GlobalConfigurationBuilder global = new GlobalConfigurationBuilder();
global
.security()
.authorization()
.principalRoleMapper(new IdentityRoleMapper())
.role("admin")
.permission(CachePermission.ALL)
.role("supervisor")
.permission(CachePermission.EXEC)
.permission(CachePermission.READ)
.permission(CachePermission.WRITE)
.role("reader")
.permission(CachePermission.READ);
ConfigurationBuilder config = new ConfigurationBuilder();
config
.security()
.enable()
.authorization()
.role("admin")
.role("supervisor")
.role("reader");8.6. Data Security for Library Mode
8.6.1. Subject and Principal Classes
To authorize access to resources, applications must first authenticate the request's source. The JAAS framework defines the term subject to represent a request's source. The
Subject class is the central class in JAAS. A Subject represents information for a single entity, such as a person or service. It encompasses the entity's principals, public credentials, and private credentials. The JAAS APIs use the existing Java 2 java.security.Principal interface to represent a principal, which is a typed name.
During the authentication process, a subject is populated with associated identities, or principals. A subject may have many principals. For example, a person may have a name principal (John Doe), a social security number principal (123-45-6789), and a user name principal (johnd), all of which help distinguish the subject from other subjects. To retrieve the principals associated with a subject, two methods are available:
public Set getPrincipals() {...}
public Set getPrincipals(Class c) {...}
getPrincipals() returns all principals contained in the subject. getPrincipals(Class c) returns only those principals that are instances of class c or one of its subclasses. An empty set is returned if the subject has no matching principals.
Note
The
java.security.acl.Group interface is a sub-interface of java.security.Principal, so an instance in the principals set may represent a logical grouping of other principals or groups of principals.
8.6.2. Obtaining a Subject
In order to use a secured cache in Library mode, you must obtain a
javax.security.auth.Subject. The Subject represents information for a single cache entity, such as a person or a service.
Red Hat JBoss Data Grid allows a JAAS Subject to be obtained either by using your container's features, or by using a third-party library.
In JBoss containers, this can be done using the following:
Subject subject = SecurityContextAssociation.getSubject();
The Subject must be populated with a set of Principals, which represent the user and groups it belongs to in your security domain, for example, an LDAP or Active Directory.
The Java EE API allows retrieval of a container-set Principal through the following methods:
- Servlets:
ServletRequest.getUserPrincipal() - EJBs:
EJBContext.getCallerPrincipal() - MessageDrivenBeans:
MessageDrivenContext.getCallerPrincipal()
The
mapper is then used to identify the principals associated with the Subject and convert them into roles that correspond to those you have defined at the container level.
A Principal is only one of the components of a Subject, which is retrieved from the
java.security.AccessControlContext. Either the container sets the Subject on the AccessControlContext, or the user must map the Principal to an appropriate Subject before wrapping the call to the JBoss Data Grid API using a Security.doAs() method.
Once a Subject has been obtained, the cache can be interacted with in the context of a PrivilegedAction.
Example 8.7. Obtaining a Subject
import org.infinispan.security.Security;
Security.doAs(subject, new PrivilegedExceptionAction<Void>() {
public Void run() throws Exception {
cache.put("key", "value");
}
});
The
Security.doAs() method is in place of the typical Subject.doAs() method. Unless the AccessControlContext must be modified for reasons specific to your application's security model, using Security.doAs() provides a performance advantage.
To obtain the current Subject, use
Security.getSubject();, which will retrieve the Subject from either the JBoss Data Grid context, or from the AccessControlContext.
8.6.3. Subject Authentication
Subject Authentication requires a JAAS login. The login process consists of the following points:
- An application instantiates a
LoginContextand passes in the name of the login configuration and aCallbackHandlerto populate theCallbackobjects, as required by the configurationLoginModules. - The
LoginContextconsults aConfigurationto load all theLoginModulesincluded in the named login configuration. If no such named configuration exists theotherconfiguration is used as a default. - The application invokes the
LoginContext.loginmethod. - The login method invokes all the loaded
LoginModules. As eachLoginModuleattempts to authenticate the subject, it invokes the handle method on the associatedCallbackHandlerto obtain the information required for the authentication process. The required information is passed to the handle method in the form of an array ofCallbackobjects. Upon success, theLoginModules associate relevant principals and credentials with the subject. - The
LoginContextreturns the authentication status to the application. Success is represented by a return from the login method. Failure is represented through a LoginException being thrown by the login method. - If authentication succeeds, the application retrieves the authenticated subject using the
LoginContext.getSubjectmethod. - After the scope of the subject authentication is complete, all principals and related information associated with the subject by the
loginmethod can be removed by invoking theLoginContext.logoutmethod.
The
LoginContext class provides the basic methods for authenticating subjects and offers a way to develop an application that is independent of the underlying authentication technology. The LoginContext consults a Configuration to determine the authentication services configured for a particular application. LoginModule classes represent the authentication services. Therefore, you can plug different login modules into an application without changing the application itself. The following code shows the steps required by an application to authenticate a subject.
CallbackHandler handler = new MyHandler();
LoginContext lc = new LoginContext("some-config", handler);
try {
lc.login();
Subject subject = lc.getSubject();
} catch(LoginException e) {
System.out.println("authentication failed");
e.printStackTrace();
}
// Perform work as authenticated Subject
// ...
// Scope of work complete, logout to remove authentication info
try {
lc.logout();
} catch(LoginException e) {
System.out.println("logout failed");
e.printStackTrace();
}
// A sample MyHandler class
class MyHandler
implements CallbackHandler
{
public void handle(Callback[] callbacks) throws
IOException, UnsupportedCallbackException
{
for (int i = 0; i < callbacks.length; i++) {
if (callbacks[i] instanceof NameCallback) {
NameCallback nc = (NameCallback)callbacks[i];
nc.setName(username);
} else if (callbacks[i] instanceof PasswordCallback) {
PasswordCallback pc = (PasswordCallback)callbacks[i];
pc.setPassword(password);
} else {
throw new UnsupportedCallbackException(callbacks[i],
"Unrecognized Callback");
}
}
}
}
Developers integrate with an authentication technology by creating an implementation of the
LoginModule interface. This allows an administrator to plug different authentication technologies into an application. You can chain together multiple LoginModules to allow for more than one authentication technology to participate in the authentication process. For example, one LoginModule may perform user name/password-based authentication, while another may interface to hardware devices such as smart card readers or biometric authenticators.
The life cycle of a
LoginModule is driven by the LoginContext object against which the client creates and issues the login method. The process consists of two phases. The steps of the process are as follows:
- The
LoginContextcreates each configuredLoginModuleusing its public no-arg constructor. - Each
LoginModuleis initialized with a call to its initialize method. TheSubjectargument is guaranteed to be non-null. The signature of the initialize method is:public void initialize(Subject subject, CallbackHandler callbackHandler, Map sharedState, Map options) - The
loginmethod is called to start the authentication process. For example, a method implementation might prompt the user for a user name and password and then verify the information against data stored in a naming service such as NIS or LDAP. Alternative implementations might interface to smart cards and biometric devices, or simply extract user information from the underlying operating system. The validation of user identity by eachLoginModuleis considered phase 1 of JAAS authentication. The signature of theloginmethod isboolean login() throws LoginException. ALoginExceptionindicates failure. A return value of true indicates that the method succeeded, whereas a return value of false indicates that the login module should be ignored. - If the
LoginContext's overall authentication succeeds,commitis invoked on eachLoginModule. If phase 1 succeeds for aLoginModule, then the commit method continues with phase 2 and associates the relevant principals, public credentials, and/or private credentials with the subject. If phase 1 fails for aLoginModule, thencommitremoves any previously stored authentication state, such as user names or passwords. The signature of thecommitmethod is:boolean commit() throws LoginException. Failure to complete the commit phase is indicated by throwing aLoginException. A return of true indicates that the method succeeded, whereas a return of false indicates that the login module should be ignored. - If the
LoginContext's overall authentication fails, then theabortmethod is invoked on eachLoginModule. Theabortmethod removes or destroys any authentication state created by the login or initialize methods. The signature of theabortmethod isboolean abort() throws LoginException. Failure to complete theabortphase is indicated by throwing aLoginException. A return of true indicates that the method succeeded, whereas a return of false indicates that the login module should be ignored. - To remove the authentication state after a successful login, the application invokes
logouton theLoginContext. This in turn results in alogoutmethod invocation on eachLoginModule. Thelogoutmethod removes the principals and credentials originally associated with the subject during thecommitoperation. Credentials should be destroyed upon removal. The signature of thelogoutmethod is:boolean logout() throws LoginException. Failure to complete the logout process is indicated by throwing aLoginException. A return of true indicates that the method succeeded, whereas a return of false indicates that the login module should be ignored.
When a
LoginModule must communicate with the user to obtain authentication information, it uses a CallbackHandler object. Applications implement the CallbackHandler interface and pass it to the LoginContext, which send the authentication information directly to the underlying login modules.
Login modules use the
CallbackHandler both to gather input from users, such as a password or smart card PIN, and to supply information to users, such as status information. By allowing the application to specify the CallbackHandler, underlying LoginModules remain independent from the different ways applications interact with users. For example, a CallbackHandler's implementation for a GUI application might display a window to solicit user input. On the other hand, a CallbackHandler implementation for a non-GUI environment, such as an application server, might simply obtain credential information by using an application server API. The CallbackHandler interface has one method to implement:
void handle(Callback[] callbacks)
throws java.io.IOException,
UnsupportedCallbackException;
The
Callback interface is the last authentication class we will look at. This is a tagging interface for which several default implementations are provided, including the NameCallback and PasswordCallback used in an earlier example. A LoginModule uses a Callback to request information required by the authentication mechanism. LoginModules pass an array of Callbacks directly to the CallbackHandler.handle method during the authentication's login phase. If a callbackhandler does not understand how to use a Callback object passed into the handle method, it throws an UnsupportedCallbackException to abort the login call.
8.6.4. Authorization Using a SecurityManager
In Red Hat JBoss Data Grid's Remote Client-Server mode, authorization is able to work without a SecurityManager for basic cache operations. In Library mode, a SecurityManager may also be used to perform some of the more complex tasks, such as distexec, map/reduce, and query.
In order to enforce access restrictions, enable the SecurityManager in your JVM using one of the following methods:
Command Line
java -Djava.security.manager ...
Programmaticaly
System.setSecurityManager(new SecurityManager());
Using the JDK's default implementation is not required, however an appropriate policy file must be supplied. The JBoss Data Grid distribution includes an example policy file, which demonstrates the permissions required by some of JBoss Data Grid's JAR files. These permissions must be integrated with those required by your application.
8.6.5. Security Manager in Java
8.6.5.1. About the Java Security Manager
Java Security Manager
The Java Security Manager is a class that manages the external boundary of the Java Virtual Machine (JVM) sandbox, controlling how code executing within the JVM can interact with resources outside the JVM. When the Java Security Manager is activated, the Java API checks with the security manager for approval before executing a wide range of potentially unsafe operations.
The Java Security Manager uses a security policy to determine whether a given action will be permitted or denied.
8.6.5.2. About Java Security Manager Policies
Security Policy
A set of defined permissions for different classes of code. The Java Security Manager compares actions requested by applications against the security policy. If an action is allowed by the policy, the Security Manager will permit that action to take place. If the action is not allowed by the policy, the Security Manager will deny that action. The security policy can define permissions based on the location of code, on the code's signature, or based on the subject's principals.
The Java Security Manager and the security policy used are configured using the Java Virtual Machine options
java.security.manager and java.security.policy.
Basic Information
A security policy's entry consists of the following configuration elements, which are connected to the policytool:
- CodeBase
- The URL location (excluding the host and domain information) where the code originates from. This parameter is optional.
- SignedBy
- The alias used in the keystore to reference the signer whose private key was used to sign the code. This can be a single value or a comma-separated list of values. This parameter is optional. If omitted, presence or lack of a signature has no impact on the Java Security Manager.
- Principals
- A list of
principal_type/principal_namepairs, which must be present within the executing thread's principal set. The Principals entry is optional. If it is omitted, it signifies that the principals of the executing thread will have no impact on the Java Security Manager. - Permissions
- A permission is the access which is granted to the code. Many permissions are provided as part of the Java Enterprise Edition 6 (Java EE 6) specification. This document only covers additional permissions which are provided by JBoss EAP 6.
Important
Refer to your container documentation on how to configure the security policy, as it may differ depending on the implementation.
8.6.5.3. Write a Java Security Manager Policy
Introduction
An application called policytool is included with most JDK and JRE distributions, for the purpose of creating and editing Java Security Manager security policies. Detailed information about policytool is linked from http://docs.oracle.com/javase/6/docs/technotes/tools/.
Procedure 8.1. Setup a new Java Security Manager Policy
Start
policytool.Start thepolicytooltool in one of the following ways.Red Hat Enterprise Linux
From your GUI or a command prompt, run/usr/bin/policytool.Microsoft Windows Server
Runpolicytool.exefrom your Start menu or from thebin\of your Java installation. The location can vary.
Create a policy.
To create a policy, select . Add the parameters you need, then click .Edit an existing policy
Select the policy from the list of existing policies, and select the button. Edit the parameters as needed.Delete an existing policy.
Select the policy from the list of existing policies, and select the button.
8.6.5.4. Run Red Hat JBoss Data Grid Server Within the Java Security Manager
To specify a Java Security Manager policy, you need to edit the Java options passed to the domain or server instance during the bootstrap process. For this reason, you cannot pass the parameters as options to the
domain.sh or standalone.sh scripts. The following procedure guides you through the steps of configuring your instance to run within a Java Security Manager policy.
Prerequisites
- Before you following this procedure, you need to write a security policy, using the
policytoolcommand which is included with your Java Development Kit (JDK). This procedure assumes that your policy is located atJDG_HOME/bin/server.policy. As an alternative, write the security policy using any text editor and manually save it asJDG_HOME/bin/server.policy - The domain or standalone server must be completely stopped before you edit any configuration files.
Perform the following procedure for each physical host or instance in your domain, if you have domain members spread across multiple systems.
Procedure 8.2. Configure the Security Manager for JBoss Data Grid Server
Open the configuration file.
Open the configuration file for editing. This file is located in one of two places, depending on whether you use a managed domain or standalone server. This is not the executable file used to start the server or domain.Managed Domain
- For Linux:
JDG_HOME/bin/domain.conf - For Windows:
JDG_HOME\bin\domain.conf.bat
Standalone Server
- For Linux:
JDG_HOME/bin/standalone.conf - For Windows:
JDG_HOME\bin\standalone.conf.bat
Add the Java options to the file.
To ensure the Java options are used, add them to the code block that begins with:if [ "x$JAVA_OPTS" = "x" ]; then
You can modify the-Djava.security.policyvalue to specify the exact location of your security policy. It should go onto one line only, with no line break. Using==when setting the-Djava.security.policyproperty specifies that the security manager will use only the specified policy file. Using=specifies that the security manager will use the specified policy combined with the policy set in thepolicy.urlsection ofJAVA_HOME/lib/security/java.security.Important
JBoss Enterprise Application Platform releases from 6.2.2 onwards require that the system propertyjboss.modules.policy-permissionsis set to true.Example 8.8. domain.conf
JAVA_OPTS="$JAVA_OPTS -Djava.security.manager -Djava.security.policy==$PWD/server.policy -Djboss.home.dir=/path/to/JDG_HOME -Djboss.modules.policy-permissions=true"
Example 8.9. domain.conf.bat
set "JAVA_OPTS=%JAVA_OPTS% -Djava.security.manager -Djava.security.policy==\path\to\server.policy -Djboss.home.dir=\path\to\JDG_HOME -Djboss.modules.policy-permissions=true"
Example 8.10. standalone.conf
JAVA_OPTS="$JAVA_OPTS -Djava.security.manager -Djava.security.policy==$PWD/server.policy -Djboss.home.dir=$JBOSS_HOME -Djboss.modules.policy-permissions=true"
Example 8.11. standalone.conf.bat
set "JAVA_OPTS=%JAVA_OPTS% -Djava.security.manager -Djava.security.policy==\path\to\server.policy -Djboss.home.dir=%JBOSS_HOME% -Djboss.modules.policy-permissions=true"
Start the domain or server.
Start the domain or server as normal.
8.7. Data Security for Remote Client Server Mode
8.7.1. About Security Realms
A security realm is a series of mappings between users and passwords, and users and roles. Security realms are a mechanism for adding authentication and authorization to your EJB and Web applications. Red Hat JBoss Data Grid Server provides two security realms by default:
ManagementRealmstores authentication information for the Management API, which provides the functionality for the Management CLI and web-based Management Console. It provides an authentication system for managing JBoss Data Grid Server itself. You could also use theManagementRealmif your application needed to authenticate with the same business rules you use for the Management API.ApplicationRealmstores user, password, and role information for Web Applications and EJBs.
Each realm is stored in two files on the filesystem:
REALM-users.propertiesstores usernames and hashed passwords.REALM-roles.propertiesstores user-to-role mappings.mgmt-groups.propertiesstores user-to-role mapping file forManagementRealm.
The properties files are stored in the
domain/configuration/ and standalone/configuration/ directories. The files are written simultaneously by the add-user.sh or add-user.bat command. When you run the command, the first decision you make is which realm to add your new user to.
8.7.2. Add a New Security Realm
Run the Management CLI.
Start thecli.shorcli.batcommand and connect to the server.Create the new security realm itself.
Run the following command to create a new security realm namedMyDomainRealmon a domain controller or a standalone server./host=master/core-service=management/security-realm=MyDomainRealm:add()
Create the references to the properties file which will store information about the new role.
Run the following command to create a pointer a file namedmyfile.properties, which will contain the properties pertaining to the new role.Note
The newly-created properties file is not managed by the includedadd-user.shandadd-user.batscripts. It must be managed externally./host=master/core-service=management/security-realm=MyDomainRealm/authentication=properties:add(path=myfile.properties)
Result
Your new security realm is created. When you add users and roles to this new realm, the information will be stored in a separate file from the default security realms. You can manage this new file using your own applications or procedures.
8.7.3. Add a User to a Security Realm
Run the
add-user.shoradd-user.batcommand.Open a terminal and change directories to theJDG_HOME/bin/directory. If you run Red Hat Enterprise Linux or another UNIX-like operating system, runadd-user.sh. If you run Microsoft Windows Server, runadd-user.bat.Choose whether to add a Management User or Application User.
For this procedure, typebto add an Application User.Choose the realm the user will be added to.
By default, the only available realm isApplicationRealm. If you have added a custom realm, you can type its name instead.Type the username, password, and roles, when prompted.
Type the desired username, password, and optional roles when prompted. Verify your choice by typingyes, or typenoto cancel the changes. The changes are written to each of the properties files for the security realm.
8.7.4. Configuring Security Realms Declaratively
In Remote Client-Server mode, a Hot Rod endpoint must specify a security realm.
The security realm declares an <authentication> and an <authorization> section.
Example 8.12. Configuring Security Realms Declaratively
<security-realms>
<security-realm name="ManagementRealm">
<authentication>
<local default-user="$local" skip-group-loading="true"/>
<properties path="mgmt-users.properties" relative-to="jboss.server.config.dir"/>
</authentication>
<authorization map-groups-to-roles="false">
<properties path="mgmt-groups.properties" relative-to="jboss.server.config.dir"/>
</authorization>
</security-realm>
<security-realm name="ApplicationRealm">
<authentication>
<local default-user="$local" allowed-users="*" skip-group-loading="true"/>
<properties path="application-users.properties" relative-to="jboss.server.config.dir"/>
</authentication>
<authorization>
<properties path="application-roles.properties" relative-to="jboss.server.config.dir"/>
</authorization>
</security-realm>
</security-realms>
The <server-identities> parameter can also be used to specify certificates.
8.7.5. Loading Roles from LDAP for Authorization (Remote Client-Server Mode)
An LDAP directory contains entries for user accounts and groups, cross referenced by attributes. Depending on the LDAP server configuration, a user entity may map the groups the user belongs to through
memberOf attributes; a group entity may map which users belong to it through uniqueMember attributes; or both mappings may be maintained by the LDAP server.
Users generally authenticate against the server using a simple user name. When searching for group membership information, depending on the directory server in use, searches could be performed using this simple name or using the distinguished name of the user's entry in the directory.
The authentication step of a user connecting to the server always happens first. Once the user is successfully authenticated the server loads the user's groups. The authentication step and the authorization step each require a connection to the LDAP server. The realm optimizes this process by reusing the authentication connection for the group loading step. As will be shown within the configuration steps below it is possible to define rules within the authorization section to convert a user's simple user name to their distinguished name. The result of a "user name to distinguished name mapping" search during authentication is cached and reused during the authorization query when the
force attribute is set to "false". When force is true, the search is performed again during authorization (while loading groups). This is typically done when different servers perform authentication and authorization.
<authorization>
<ldap connection="...">
<!-- OPTIONAL -->
<username-to-dn force="true">
<!-- Only one of the following. -->
<username-is-dn />
<username-filter base-dn="..." recursive="..." user-dn-attribute="..." attribute="..." />
<advanced-filter base-dn="..." recursive="..." user-dn-attribute="..." filter="..." />
</username-to-dn>
<group-search group-name="..." iterative="..." group-dn-attribute="..." group-name-attribute="..." >
<!-- One of the following -->
<group-to-principal base-dn="..." recursive="..." search-by="...">
<membership-filter principal-attribute="..." />
</group-to-principal>
<principal-to-group group-attribute="..." />
</group-search>
</ldap>
</authorization>Important
These examples specify some attributes with their default values. This is done for demonstration. Attributes that specify their default values are removed from the configuration when it is persisted by the server. The exception is the
force attribute. It is required, even when set to the default value of false.
username-to-dn
The
username-to-dn element specifies how to map the user name to the distinguished name of their entry in the LDAP directory. This element is only required when both of the following are true:
- The authentication and authorization steps are against different LDAP servers.
- The group search uses the distinguished name.
- 1:1 username-to-dn
- This specifies that the user name entered by the remote user is the user's distinguished name.
<username-to-dn force="false"> <username-is-dn /> </username-to-dn>
This defines a 1:1 mapping and there is no additional configuration. - username-filter
- The next option is very similar to the simple option described above for the authentication step. A specified attribute is searched for a match against the supplied user name.
<username-to-dn force="true"> <username-filter base-dn="dc=people,dc=harold,dc=example,dc=com" recursive="false" attribute="sn" user-dn-attribute="dn" /> </username-to-dn>The attributes that can be set here are:base-dn: The distinguished name of the context to begin the search.recursive: Whether the search will extend to sub contexts. Defaults tofalse.attribute: The attribute of the users entry to try and match against the supplied user name. Defaults touid.user-dn-attribute: The attribute to read to obtain the users distinguished name. Defaults todn.
- advanced-filter
- The final option is to specify an advanced filter, as in the authentication section this is an opportunity to use a custom filter to locate the users distinguished name.
<username-to-dn force="true"> <advanced-filter base-dn="dc=people,dc=harold,dc=example,dc=com" recursive="false" filter="sAMAccountName={0}" user-dn-attribute="dn" /> </username-to-dn>For the attributes that match those in the username-filter example, the meaning and default values are the same. There is one new attribute:filter: Custom filter used to search for a user's entry where the user name will be substituted in the{0}place holder.
Important
The XML must remain valid after the filter is defined so if any special characters are used such as&ensure the proper form is used. For example&for the&character.
The Group Search
There are two different styles that can be used when searching for group membership information. The first style is where the user's entry contains an attribute that references the groups the user is a member of. The second style is where the group contains an attribute referencing the users entry.
When there is a choice of which style to use Red Hat recommends that the configuration for a user's entry referencing the group is used. This is because with this method group information can be loaded by reading attributes of known distinguished names without having to perform any searches. The other approach requires extensive searches to identify the groups that reference the user.
Before describing the configuration here are some LDIF examples to illustrate this.
Example 8.13. Principal to Group - LDIF example.
This example illustrates where we have a user
TestUserOne who is a member of GroupOne, GroupOne is in turn a member of GroupFive. The group membership is shown by the use of a memberOf attribute which is set to the distinguished name of the group of which the user (or group) is a member.
It is not shown here but a user could potentially have multiple
memberOf attributes set, one for each group of which the user is directly a member.
dn: uid=TestUserOne,ou=users,dc=principal-to-group,dc=example,dc=org objectClass: extensibleObject objectClass: top objectClass: groupMember objectClass: inetOrgPerson objectClass: uidObject objectClass: person objectClass: organizationalPerson cn: Test User One sn: Test User One uid: TestUserOne distinguishedName: uid=TestUserOne,ou=users,dc=principal-to-group,dc=example,dc=org memberOf: uid=GroupOne,ou=groups,dc=principal-to-group,dc=example,dc=org memberOf: uid=Slashy/Group,ou=groups,dc=principal-to-group,dc=example,dc=org userPassword:: e1NTSEF9WFpURzhLVjc4WVZBQUJNbEI3Ym96UVAva0RTNlFNWUpLOTdTMUE9PQ== dn: uid=GroupOne,ou=groups,dc=principal-to-group,dc=example,dc=org objectClass: extensibleObject objectClass: top objectClass: groupMember objectClass: group objectClass: uidObject uid: GroupOne distinguishedName: uid=GroupOne,ou=groups,dc=principal-to-group,dc=example,dc=org memberOf: uid=GroupFive,ou=subgroups,ou=groups,dc=principal-to-group,dc=example,dc=org dn: uid=GroupFive,ou=subgroups,ou=groups,dc=principal-to-group,dc=example,dc=org objectClass: extensibleObject objectClass: top objectClass: groupMember objectClass: group objectClass: uidObject uid: GroupFive distinguishedName: uid=GroupFive,ou=subgroups,ou=groups,dc=principal-to-group,dc=example,dc=org
Example 8.14. Group to Principal - LDIF Example
This example shows the same user
TestUserOne who is a member of GroupOne which is in turn a member of GroupFive - however in this case it is an attribute uniqueMember from the group to the user being used for the cross reference.
Again the attribute used for the group membership cross reference can be repeated, if you look at GroupFive there is also a reference to another user TestUserFive which is not shown here.
dn: uid=TestUserOne,ou=users,dc=group-to-principal,dc=example,dc=org objectClass: top objectClass: inetOrgPerson objectClass: uidObject objectClass: person objectClass: organizationalPerson cn: Test User One sn: Test User One uid: TestUserOne userPassword:: e1NTSEF9SjR0OTRDR1ltaHc1VVZQOEJvbXhUYjl1dkFVd1lQTmRLSEdzaWc9PQ== dn: uid=GroupOne,ou=groups,dc=group-to-principal,dc=example,dc=org objectClass: top objectClass: groupOfUniqueNames objectClass: uidObject cn: Group One uid: GroupOne uniqueMember: uid=TestUserOne,ou=users,dc=group-to-principal,dc=example,dc=org dn: uid=GroupFive,ou=subgroups,ou=groups,dc=group-to-principal,dc=example,dc=org objectClass: top objectClass: groupOfUniqueNames objectClass: uidObject cn: Group Five uid: GroupFive uniqueMember: uid=TestUserFive,ou=users,dc=group-to-principal,dc=example,dc=org uniqueMember: uid=GroupOne,ou=groups,dc=group-to-principal,dc=example,dc=org
General Group Searching
Before looking at the examples for the two approaches shown above we first need to define the attributes common to both of these.
<group-search group-name="..." iterative="..." group-dn-attribute="..." group-name-attribute="..." >
...
</group-search>group-name: This attribute is used to specify the form that should be used for the group name returned as the list of groups of which the user is a member. This can either be the simple form of the group name or the group's distinguished name. If the distinguished name is required this attribute can be set toDISTINGUISHED_NAME. Defaults toSIMPLE.iterative: This attribute is used to indicate if, after identifying the groups a user is a member of, we should also iteratively search based on the groups to identify which groups the groups are a member of. If iterative searching is enabled we keep going until either we reach a group that is not a member if any other groups or a cycle is detected. Defaults tofalse.
Cyclic group membership is not a problem. A record of each search is kept to prevent groups that have already been searched from being searched again.
Important
For iterative searching to work the group entries need to look the same as user entries. The same approach used to identify the groups a user is a member of is then used to identify the groups of which the group is a member. This would not be possible if for group to group membership the name of the attribute used for the cross reference changes or if the direction of the reference changes.
group-dn-attribute: On an entry for a group which attribute is its distinguished name. Defaults todn.group-name-attribute: On an entry for a group which attribute is its simple name. Defaults touid.
Example 8.15. Principal to Group Example Configuration
Based on the example LDIF from above here is an example configuration iteratively loading a user's groups where the attribute used to cross reference is the
memberOf attribute on the user.
<authorization>
<ldap connection="LocalLdap">
<username-to-dn>
<username-filter base-dn="ou=users,dc=principal-to-group,dc=example,dc=org" recursive="false" attribute="uid" user-dn-attribute="dn" />
</username-to-dn>
<group-search group-name="SIMPLE" iterative="true" group-dn-attribute="dn" group-name-attribute="uid">
<principal-to-group group-attribute="memberOf" />
</group-search>
</ldap>
</authorization>
The most important aspect of this configuration is that the
principal-to-group element has been added with a single attribute.
group-attribute: The name of the attribute on the user entry that matches the distinguished name of the group the user is a member of. Defaults tomemberOf.
Example 8.16. Group to Principal Example Configuration
This example shows an iterative search for the group to principal LDIF example shown above.
<authorization>
<ldap connection="LocalLdap">
<username-to-dn>
<username-filter base-dn="ou=users,dc=group-to-principal,dc=example,dc=org" recursive="false" attribute="uid" user-dn-attribute="dn" />
</username-to-dn>
<group-search group-name="SIMPLE" iterative="true" group-dn-attribute="dn" group-name-attribute="uid">
<group-to-principal base-dn="ou=groups,dc=group-to-principal,dc=example,dc=org" recursive="true" search-by="DISTINGUISHED_NAME">
<membership-filter principal-attribute="uniqueMember" />
</group-to-principal>
</group-search>
</ldap>
</authorization>
Here an element
group-to-principal is added. This element is used to define how searches for groups that reference the user entry will be performed. The following attributes are set:
base-dn: The distinguished name of the context to use to begin the search.recursive: Whether sub-contexts also be searched. Defaults tofalse.search-by: The form of the role name used in searches. Valid values areSIMPLEandDISTINGUISHED_NAME. Defaults toDISTINGUISHED_NAME.
Within the group-to-principal element there is a membership-filter element to define the cross reference.
principal-attribute: The name of the attribute on the group entry that references the user entry. Defaults tomember.
8.7.6. Hot Rod Interface Security
8.7.6.1. Publish Hot Rod Endpoints as a Public Interface
Red Hat JBoss Data Grid's Hot Rod server operates as a management interface as a default. To extend its operations to a public interface, alter the value of the
interface parameter in the socket-binding element from management to public as follows:
<socket-binding name="hotrod" interface="public" port="11222" />
8.7.6.2. Encryption of communication between Hot Rod Server and Hot Rod client
Hot Rod can be encrypted using TLS/SSL, and has the option to require certificate-based client authentication.
Use the following procedure to secure the Hot Rod connector using SSL.
Procedure 8.3. Secure Hot Rod Using SSL/TLS
Generate a Keystore
Create a Java Keystore using the keytool application distributed with the JDK and add your certificate to it. The certificate can be either self signed, or obtained from a trusted CA depending on your security policy.Place the Keystore in the Configuration Directory
Put the keystore in the~/JDG_HOME/standalone/configurationdirectory with thestandalone-hotrod-ssl.xmlfile from the~/JDG_HOME/docs/examples/configsdirectory.Declare an SSL Server Identity
Declare an SSL server identity within a security realm in the management section of the configuration file. The SSL server identity must specify the path to a keystore and its secret key.<server-identities> <ssl protocol="..."> <keystore path="..." relative-to="..." keystore-password="${VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::ENCRYPTED_VALUE}" /> </ssl> <secret value="..." /> </server-identities>See Section 8.7.7.4, “Configure Hot Rod Authentication (X.509)” for details about these parameters.Add the Security Element
Add the security element to the Hot Rod connector as follows:<hotrod-connector socket-binding="hotrod" cache-container="local"> <encryption ssl="true" security-realm="ApplicationRealm" require-ssl-client-auth="false" /> </hotrod-connector>Server Authentication of Certificate
If you require the server to perform authentication of the client certificate, create a truststore that contains the valid client certificates and set therequire-ssl-client-authattribute totrue.
Start the Server
Start the server using the following:bin/standalone.sh -c standalone-hotrod-ssl.xml
This will start a server with a Hot Rod endpoint on port 11222. This endpoint will only accept SSL connections.
Securing Hot Rod using SSL can also be configured programmatically. This configuration should be used in order to prevent passwords from being stored as plain text in configuration files
Example 8.17. Secure Hot Rod Using SSL/TLS
package org.infinispan.client.hotrod.configuration;
import java.util.Arrays;
import javax.net.ssl.KeyManager;
import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
public class SslConfiguration {
private final boolean enabled;
private final String keyStoreFileName;
private final char[] VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::keyStorePassword;
private final SSLContext sslContext;
private final String trustStoreFileName;
private final char[] VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::trustStorePassword;
SslConfiguration(boolean enabled, String keyStoreFileName, char[] keyStorePassword, SSLContext sslContext, String trustStoreFileName, char[] trustStorePassword) {
this.enabled = enabled;
this.keyStoreFileName = keyStoreFileName;
this.keyStorePassword = VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::keyStorePassword;
this.sslContext = sslContext;
this.trustStoreFileName = trustStoreFileName;
this.trustStorePassword = VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::trustStorePassword;
}
public boolean enabled() {
return enabled;
}
public String keyStoreFileName() {
return keyStoreFileName;
}
public char[] keyStorePassword() {
return keyStorePassword;
}
public SSLContext sslContext() {
return sslContext;
}
public String trustStoreFileName() {
return trustStoreFileName;
}
public char[] trustStorePassword() {
return trustStorePassword;
}
@Override
public String toString() {
return "SslConfiguration [enabled=" + enabled + ", keyStoreFileName="
+ keyStoreFileName + ", sslContext=" + sslContext + ", trustStoreFileName=" + trustStoreFileName + "]";
}
}
Important
To prevent plain text passwords from appearing in configurations or source codes, plain text passwords should be changed to Vault passwords. For more information about how to set up Vault passwords, see the Red Hat Enterprise Application Platform Security Guide.
8.7.7. User Authentication over Hot Rod Using SASL
User authentication over Hot Rod can be implemented using the following Simple Authentication and Security Layer (SASL) mechanisms:
PLAINis the least secure mechanism because credentials are transported in plain text format. However, it is also the simplest mechanism to implement. This mechanism can be used in conjunction with encryption (SSL) for additional security.DIGEST-MD5is a mechanism than hashes the credentials before transporting them. As a result, it is more secure than thePLAINmechanism.GSSAPIis a mechanism that uses Kerberos tickets. As a result, it requires a correctly configured Kerberos Domain Controller (for example, Microsoft Active Directory).EXTERNALis a mechanism that obtains the required credentials from the underlying transport (for example, from aX.509client certificate) and therefore requires client certificate encryption to work correctly.
8.7.7.1. Configure Hot Rod Authentication (GSSAPI/Kerberos)
Use the following steps to set up Hot Rod Authentication using the SASL GSSAPI/Kerberos mechanism:
Procedure 8.4. Configure SASL GSSAPI/Kerberos Authentication
Server-side Configuration
The following steps must be configured on the server-side:- Define a Kerberos security login module using the security domain subsystem:
<system-properties> <property name="java.security.krb5.conf" value="/tmp/infinispan/krb5.conf"/> <property name="java.security.krb5.debug" value="true"/> <property name="jboss.security.disable.secdomain.option" value="true"/> </system-properties> <security-domain name="infinispan-server" cache-type="default"> <authentication> <login-module code="Kerberos" flag="required"> <module-option name="debug" value="true"/> <module-option name="storeKey" value="true"/> <module-option name="refreshKrb5Config" value="true"/> <module-option name="useKeyTab" value="true"/> <module-option name="doNotPrompt" value="true"/> <module-option name="keyTab" value="/tmp/infinispan/infinispan.keytab"/> <module-option name="principal" value="HOTROD/localhost@INFINISPAN.ORG"/> </login-module> </authentication> </security-domain> - Configure a Hot Rod connector as follows:
<hotrod-connector socket-binding="hotrod" cache-container="default"> <authentication security-realm="ApplicationRealm"> <sasl server-name="node0" mechanisms="{mechanism_name}" qop="{qop_name}" strength="{value}"> <policy> <no-anonymous value="true" /> </policy> <property name="com.sun.security.sasl.digest.utf8">true</property> </sasl> </authentication> </hotrod-connector>- The
server-nameattribute specifies the name that the server declares to incoming clients. The client configuration must also contain the same server name value. - The
server-context-nameattribute specifies the name of the login context used to retrieve a server subject for certain SASL mechanisms (for example, GSSAPI). - The
mechanismsattribute specifies the authentication mechanism in use. See Section 8.7.7, “User Authentication over Hot Rod Using SASL” for a list of supported mechanisms. - The
qopattribute specifies the SASL quality of protection value for the configuration. Supported values for this attribute areauth(authentication),auth-int(authentication and integrity, meaning that messages are verified against checksums to detect tampering), andauth-conf(authentication, integrity, and confidentiality, meaning that messages are also encrypted). Multiple values can be specified, for example,auth-int auth-conf. The ordering implies preference, so the first value which matches both the client and server's preference is chosen. - The
strengthattribute specifies the SASL cipher strength. Valid values arelow,medium, andhigh. - The
no-anonymouselement within thepolicyelement specifies whether mechanisms that accept anonymous login are permitted. Set this value tofalseto permit andtrueto deny.
Client-side Configuration
The following steps must be configured on the client-side:- Define a login module in a login configuration file (
gss.conf) on the client side:GssExample { com.sun.security.auth.module.Krb5LoginModule required client=TRUE; }; - Set up the following system properties:
java.security.auth.login.config=gss.conf java.security.krb5.conf=/etc/krb5.conf
Note
Thekrb5.conffile is dependent on the environment and must point to the Kerberos Key Distribution Center. - Configure the Hot Rod Client:
public class MyCallbackHandler implements CallbackHandler { final private String username; final private char[] password; final private String realm; public MyCallbackHandler() { } public MyCallbackHandler (String username, String realm, char[] password) { this.username = username; this.password = password; this.realm = realm; } @Override public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException { for (Callback callback : callbacks) { if (callback instanceof NameCallback) { NameCallback nameCallback = (NameCallback) callback; nameCallback.setName(username); } else if (callback instanceof PasswordCallback) { PasswordCallback passwordCallback = (PasswordCallback) callback; passwordCallback.setPassword(password); } else if (callback instanceof AuthorizeCallback) { AuthorizeCallback authorizeCallback = (AuthorizeCallback) callback; authorizeCallback.setAuthorized(authorizeCallback.getAuthenticationID().equals( authorizeCallback.getAuthorizationID())); } else if (callback instanceof RealmCallback) { RealmCallback realmCallback = (RealmCallback) callback; realmCallback.setText(realm); } else { throw new UnsupportedCallbackException(callback); } } }} LoginContext lc = new LoginContext("GssExample", new MyCallbackHandler("krb_user", "krb_password".toCharArray()));lc.login();Subject clientSubject = lc.getSubject(); ConfigurationBuilder clientBuilder = new ConfigurationBuilder();clientBuilder .addServer() .host("127.0.0.1") .port(11222) .socketTimeout(1200000) .security() .authentication() .enable() .serverName("infinispan-server") .saslMechanism("GSSAPI") .clientSubject(clientSubject) .callbackHandler(new MyCallbackHandler());remoteCacheManager = new RemoteCacheManager(clientBuilder.build());RemoteCache<String, String> cache = remoteCacheManager.getCache("secured");
8.7.7.2. Configure Hot Rod Authentication (MD5)
Use the following steps to set up Hot Rod Authentication using the SASL using the MD5 mechanism:
Procedure 8.5. Configure Hot Rod Authentication (MD5)
- Set up the Hot Rod Connector configuration by adding the
saslelement to theauthenticationelement (for details on theauthenticationelement, see Section 8.7.4, “Configuring Security Realms Declaratively”) as follows:<hotrod-connector socket-binding="hotrod" cache-container="default"> <authentication security-realm="ApplicationRealm"> <sasl server-name="myhotrodserver" mechanisms="DIGEST-MD5" qop="auth" /> </authentication> </hotrod-connector>- The
server-nameattribute specifies the name that the server declares to incoming clients. The client configuration must also contain the same server name value. - The
mechanismsattribute specifies the authentication mechanism in use. See Section 8.7.7, “User Authentication over Hot Rod Using SASL” for a list of supported mechanisms. - The
qopattribute specifies the SASL quality of production value for the configuration. Supported values for this attribute areauth,auth-int, andauth-conf.
- Connect the client to the configured Hot Rod connector as follows:
public class MyCallbackHandler implements CallbackHandler { final private String username; final private char[] password; final private String realm; public MyCallbackHandler (String username, String realm, char[] password) { this.username = username; this.password = password; this.realm = realm; } @Override public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException { for (Callback callback : callbacks) { if (callback instanceof NameCallback) { NameCallback nameCallback = (NameCallback) callback; nameCallback.setName(username); } else if (callback instanceof PasswordCallback) { PasswordCallback passwordCallback = (PasswordCallback) callback; passwordCallback.setPassword(password); } else if (callback instanceof AuthorizeCallback) { AuthorizeCallback authorizeCallback = (AuthorizeCallback) callback; authorizeCallback.setAuthorized(authorizeCallback.getAuthenticationID().equals( authorizeCallback.getAuthorizationID())); } else if (callback instanceof RealmCallback) { RealmCallback realmCallback = (RealmCallback) callback; realmCallback.setText(realm); } else { throw new UnsupportedCallbackException(callback); } } }} ConfigurationBuilder clientBuilder = new ConfigurationBuilder();clientBuilder .addServer() .host("127.0.0.1") .port(11222) .socketTimeout(1200000) .security() .authentication() .enable() .serverName("myhotrodserver") .saslMechanism("DIGEST-MD5") .callbackHandler(new MyCallbackHandler("myuser", "ApplicationRealm", "qwer1234!".toCharArray()));remoteCacheManager = new RemoteCacheManager(clientBuilder.build());RemoteCache<String, String> cache = remoteCacheManager.getCache("secured");
8.7.7.3. Configure Hot Rod Using LDAP/Active Directory
Use the following to configure authentication over Hot Rod using LDAP or Microsoft Active Directory:
<security-realms> <security-realm name="ApplicationRealm"> <authentication> <ldap connection="ldap_connection" recursive="true" base-dn="cn=users,dc=infinispan,dc=org"> <username-filter attribute="cn" /> </ldap> </authentication> </security-realm> </security-realms> <outbound-connections> <ldap name="ldap_connection" url="ldap://my_ldap_server" search-dn="CN=test,CN=Users,DC=infinispan,DC=org" search-credential="Test_password"/> </outbound-connections>
The following are some details about the elements and parameters used in this configuration:
- The
security-realmelement'snameparameter specifies the security realm to reference to use when establishing the connection. - The
authenticationelement contains the authentication details. - The
ldapelement specifies how LDAP searches are used to authenticate a user. First, a connection to LDAP is established and a search is conducted using the supplied user name to identify the distinguished name of the user. A subsequent connection to the server is established using the password supplied by the user. If the second connection succeeds, the authentication is a success.- The
connectionparameter specifies the name of the connection to use to connect to LDAP. - The (optional)
recursiveparameter specifies whether the filter is executed recursively. The default value for this parameter isfalse. - The
base-dnparameter specifies the distinguished name of the context to use to begin the search from. - The (optional)
user-dnparameter specifies which attribute to read for the user's distinguished name after the user is located. The default value for this parameter isdn.
- The
outbound-connectionselement specifies the name of the connection used to connect to the LDAP. directory. - The
ldapelement specifies the properties of the outgoing LDAP connection.- The
nameparameter specifies the unique name used to reference this connection. - The
urlparameter specifies the URL used to establish the LDAP connection. - The
search-dnparameter specifies the distinguished name of the user to authenticate and to perform the searches. - The
search-credentialparameter specifies the password required to connect to LDAP as thesearch-dn. - The (optional)
initial-context-factoryparameter allows the overriding of the initial context factory. the default value of this parameter iscom.sun.jndi.ldap.LdapCtxFactory.
8.7.7.4. Configure Hot Rod Authentication (X.509)
The
X.509 certificate can be installed at the node, and be made available to other nodes for authentication purposes for inbound and outbound SSL connections. This is enabled using the <server-identities/> element of a security realm definition, which defines how a server appears to external applications. This element can be used to configure a password to be used when establishing a remote connection, as well as the loading of an X.509 key.
The following example shows how to install an
X.509 certificate on the node.
<security-realm name="ApplicationRealm">
<server-identities>
<ssl protocol="...">
<keystore path="..." relative-to="..." keystore-password="..." alias="..." key-password="..." />
</ssl>
</server-identities>
[... authentication/authorization ...]
</security-realms>
In the provided example, the SSL element contains the <keystore/> element, which is used to define how to load the key from the file-based keystore. The following parameters ave available for this element.
Table 8.4. <server-identities/> Options
| Parameter | Mandatory/Optional | Description |
|---|---|---|
path | Mandatory | This is the path to the keystore, this can be an absolute path or relative to the next attribute. |
relative-to | Optional | The name of a service representing a path the keystore is relative to. |
keystore-password | Mandatory | The password required to open the keystore. |
alias | Optional | The alias of the entry to use from the keystore - for a keystore with multiple entries in practice the first usable entry is used but this should not be relied on and the alias should be set to guarantee which entry is used. |
key-password | Optional | The password to load the key entry, if omitted the keystore-password will be used instead. |
Note
If the following error occurs, specify a
key-password as well as an alias to ensure only one key is loaded.
UnrecoverableKeyException: Cannot recover key
8.8. Active Directory Authentication (Non-Kerberos)
See Example 8.2, “Example of JBoss EAP LDAP login module configuration” for a non-Kerberos Active Directory Authentication configuration example.
8.9. Active Directory Authentication Using Kerberos (GSSAPI)
When using Red Hat JBoss Data Grid with Microsoft Active Directory, data security can be enabled via Kerberos authentication. To configure Kerberos authentication for Microsoft Active Directory, use the following procedure.
Procedure 8.6. Configure Kerberos Authentication for Active Directory (Library Mode)
- Configure JBoss EAP server to authenticate itself to Kerberos. This can be done by configuring a dedicated security domain, for example:
<security-domain name="ldap-service" cache-type="default"> <authentication> <login-module code="Kerberos" flag="required"> <module-option name="storeKey" value="true"/> <module-option name="useKeyTab" value="true"/> <module-option name="refreshKrb5Config" value="true"/> <module-option name="principal" value="ldap/localhost@INFINISPAN.ORG"/> <module-option name="keyTab" value="${basedir}/keytab/ldap.keytab"/> <module-option name="doNotPrompt" value="true"/> </login-module> </authentication> </security-domain> - The security domain for authentication must be configured correctly for JBoss EAP, an application must have a valid Kerberos ticket. To initiate the Kerberos ticket, you must reference another security domain using
<module-option name="usernamePasswordDomain" value="krb-admin"/>
. This points to the standard Kerberos login module described in Step 3.<security-domain name="ispn-admin" cache-type="default"> <authentication> <login-module code="SPNEGO" flag="requisite"> <module-option name="password-stacking" value="useFirstPass"/> <module-option name="serverSecurityDomain" value="ldap-service"/> <module-option name="usernamePasswordDomain" value="krb-admin"/> </login-module> <login-module code="AdvancedAdLdap" flag="required"> <module-option name="password-stacking" value="useFirstPass"/> <module-option name="bindAuthentication" value="GSSAPI"/> <module-option name="jaasSecurityDomain" value="ldap-service"/> <module-option name="java.naming.provider.url" value="ldap://localhost:389"/> <module-option name="baseCtxDN" value="ou=People,dc=infinispan,dc=org"/> <module-option name="baseFilter" value="(krb5PrincipalName={0})"/> <module-option name="rolesCtxDN" value="ou=Roles,dc=infinispan,dc=org"/> <module-option name="roleFilter" value="(member={1})"/> <module-option name="roleAttributeID" value="cn"/> </login-module> </authentication> </security-domain> - The security domain authentication configuration described in the previous step points to the following standard Kerberos login module:
<security-domain name="krb-admin" cache-type="default"> <authentication> <login-module code="Kerberos" flag="required"> <module-option name="useKeyTab" value="true"/> <module-option name="principal" value="admin@INFINISPAN.ORG"/> <module-option name="keyTab" value="${basedir}/keytab/admin.keytab"/> </login-module> </authentication> </security-domain>
8.10. The Security Audit Logger
Red Hat JBoss Data Grid includes a logger to audit security logs for the cache, specifically whether a cache or a cache manager operation was allowed or denied for various operations.
The default audit logger is
org.infinispan.security.impl.DefaultAuditLogger. This logger outputs audit logs using the available logging framework (for example, JBoss Logging) and provides results at the TRACE level and the AUDIT category.
To send the
AUDIT category to either a log file, a JMS queue, or a database, use the appropriate log appender.
8.10.1. Configure the Security Audit Logger (Library Mode)
Use the following to declaratively configure the audit logger in Red Hat JBoss Data Grid:
<infinispan> ... <global-security> <authorization audit-logger = "org.infinispan.security.impl.DefaultAuditLogger"> ... </authorization> </global-security> ... </infinispan>
Use the following to programatically configure the audit logger in JBoss Data Grid:
GlobalConfigurationBuilder global = new GlobalConfigurationBuilder();
global.security()
.authorization()
.auditLogger(new DefaultAuditLogger());8.10.2. Configure the Security Audit Logger (Remote Client-Server Mode)
Use the following code to configure the audit logger in Red Hat JBoss Data Grid Remote Client-Server Mode.
To use a different audit logger, specify it in the
<authorization> element. The <authorization> element must be within the <cache-container> element in the Infinispan subsystem (in the standalone.xml configuration file).
<cache-container name="local" default-cache="default"> <security> <authorization audit-logger="org.infinispan.security.impl.DefaultAuditLogger"> <identity-role-mapper/> <role name="admin" permissions="ALL"/> <role name="reader" permissions="READ"/> <role name="writer" permissions="WRITE"/> <role name="supervisor" permissions="ALL_READ ALL_WRITE"/> </authorization> </security> <local-cache name="default" start="EAGER"> <locking isolation="NONE" acquire-timeout="30000" concurrency-level="1000" striping="false"/> <transaction mode="NONE"/> <security> <authorization roles="admin reader writer supervisor"/> </security> </local-cache>
Note
The default audit logger for server mode is
org.jboss.as.clustering.infinispan.subsystem.ServerAuditLogger which sends the log messages to the server audit log. See the Management Interface Audit Logging chapter in the JBoss Enterprise Application Platform Administration and Configuration Guide for more information.
8.10.3. Custom Audit Loggers
Users can implement custom audit loggers in Red Hat JBoss Data Grid Library and Remote Client-Server Mode. The custom logger must implement the
org.infinispan.security.AuditLogger interface. If no custom logger is provided, the default logger (DefaultAuditLogger) is used.
Chapter 9. Security for Cluster Traffic
9.1. Node Authentication and Authorization (Remote Client-Server Mode)
Security can be enabled at node level via SASL protocol, which enables node authentication against a security realm. This requires nodes to authenticate each other when joining or merging with a cluster. For detailed information about security realms, see Section 8.7.1, “About Security Realms”.
The following example depicts the <sasl /> element, which leverages the SASL protocol. Both
DIGEST-MD5 or GSSAPI mechanisms are currently supported.
Example 9.1. Configure SASL Authentication
<management>
<security-realms>
...
<security-realm name="ClusterRealm">
<authentication>
<properties path="cluster-users.properties" relative-to="jboss.server.config.dir"/>
</authentication>
<authorization>
<properties path="cluster-roles.properties" relative-to="jboss.server.config.dir"/>
</authorization>
</security-realm>
</security-realms>
...
</security-realms>
</management>
<stack name="udp">
...
<sasl mech="DIGEST-MD5" security-realm="ClusterRealm" cluster-role="cluster">
<property name="client_name">node1</property>
<property name="client_password">password</property>
</sasl>
...
</stack>
In the provided example, the ndoes use the
DIGEST-MD5 mechanism to authenticate against the ClusterRealm. In order to join, nodes must have the cluster role.
The
cluster-role attribute determines the role all nodes must belong to in the security realm in order to JOIN or MERGE with the cluster. Unless it has been specified, the cluster-role attribute is the name of the clustered <cache-container> by default. Each node identifies itself using the client-name property. If none is specified, the hostname on which the server is running will be used.
This name can also be overridden by specifying the
jboss.node.name system property that can be overridden on the command line. For example:
$ clustered.sh -Djboss.node.name=node001
Note
JGroups AUTH protocol is not integrated with security realms, and its use is not advocated for Red Hat JBoss Data Grid.
9.1.1. Configure Node Authentication for Cluster Security (DIGEST-MD5)
The following example demonstrates how to use
DIGEST-MD5 with a properties-based security realm, with a dedicated realm for cluster node.
Example 9.2. Using the DIGEST-MD5 Mechanism
<management>
<security-realms>
<security-realm name="ClusterRealm">
<authentication>
<properties path="cluster-users.properties" relative-to="jboss.server.config.dir"/>
</authentication>
<authorization>
<properties path="cluster-roles.properties" relative-to="jboss.server.config.dir"/>
</authorization>
</security-realm>
</security-realms>
</management>
<subsystem xmlns="urn:infinispa:server:jgroups:6.1" default-stack="${jboss.default.jgroups.stack:udp}">
<stack name="udp">
<transport type="UDP" socket-binding="jgroups-udp"/>
<protocol type="PING"/>
<protocol type="MERGE2"/>
<protocol type="FD_SOCK" socket-binding="jgroups-udp-fd"/>
<protocol type="FD_ALL"/>
<protocol type="pbcast.NAKACK"/>
<protocol type="UNICAST2"/>
<protocol type="pbcast.STABLE"/>
<protocol type="pbcast.GMS"/>
<protocol type="UFC"/>
<protocol type="MFC"/>
<protocol type="FRAG2"/>
<protocol type="RSVP"/>
<sasl security-realm="ClusterRealm" mech="DIGEST-MD5">
<property name="client_password>...</property>
</sasl>
</stack>
</subsystem>
<subsystem xmlns="urn:infinispan:server:core:6.1" default-cache-container="clustered">
<cache-container name="clustered" default-cache="default">
<transport executor="infinispan-transport" lock-timeout="60000" stack="udp"/>
<!-- various clustered cache definitions here -->
</cache-container>
</subsystem>
In the provided example, supposing the hostnames of the various nodes are
node001, node002, node003, the cluster-users.properties will contain:
node001=/<node001passwordhash>/node002=/<node002passwordhash>/node003=/<node003passwordhash>/
The
cluster-roles.properties will contain:
- node001=clustered
- node002=clustered
- node003=clustered
To generate these values, the following
add-users.sh script can be used:
$ add-user.sh -up cluster-users.properties -gp cluster-roles.properties -r ClusterRealm -u node001 -g clustered -p <password>
The
MD5 password hash of the node must also be placed in the "client_password" property of the <sasl/> element.
<property name="client_password>...</property>
Note
To increase security, it is recommended that this password be stored using a Vault. For more information about vault expressions, see the Red Hat Enterprise Application Platform Security Guide
Once node security has been set up as discussed here, the cluster coordinator will validate each
JOINing and MERGEing node's credentials against the realm before letting the node become part of the cluster view.
9.1.2. Configure Node Authentication for Cluster Security (GSSAPI/Kerberos)
When using the
GSSAPI mechanism, the client_name is used as the name of a Kerberos-enabled login module defined within the security domain subsystem. For a full procedure on how to do this, see Section 8.7.7.1, “Configure Hot Rod Authentication (GSSAPI/Kerberos)”.
Example 9.3. Using the Kerberos Login Module
<security-domain name="krb-node0" cache-type="default">
<authentication>
<login-module code="Kerberos" flag="required">
<module-option name="storeKey" value="true"/>
<module-option name="useKeyTab" value="true"/>
<module-option name="refreshKrb5Config" value="true"/>
<module-option name="principal" value="jgroups/node0/clustered@INFINISPAN.ORG"/>
<module-option name="keyTab" value="${jboss.server.config.dir}/keytabs/jgroups_node0_clustered.keytab"/>
<module-option name="doNotPrompt" value="true"/>
</login-module>
</authentication>
</security-domain>
The following property must be set in the <sasl/> element to reference it:
<sasl ...>
<property name="login_module_name">...</property>
</sasl>
As a result, the
authentication section of the security realm is ignored, as the nodes will be validated against the Kerberos Domain Controller. The authorization configuration is still required, as the node principal must belong to the required cluster-role.
In all cases, it is recommended that a shared authorization database, such as LDAP, be used to validate node membership in order to simplify administration.
By default, the principal of the joining node must be in the following format:
jgroups/$NODE_NAME/$CACHE_CONTAINER_NAME@REALM
9.2. Configure Node Security in Library Mode
In Library mode, node authentication is configured directly in the JGroups configuration. JGroups can be configured so that nodes must authenticate each other when joining or merging with a cluster. The authentication uses SASL and is enabled by adding the
SASL protocol to your JGroups XML configuration.
SASL relies on JAAS notions, such as
CallbackHandlers, to obtain certain information necessary for the authentication handshake. Users must supply their own CallbackHandlers on both client and server sides.
Important
The
JAAS API is only available when configuring user authentication and authorization, and is not available for node security.
Note
In the provided example,
CallbackHandler classes are examples only, and not contained in the Red Hat JBoss Data Grid release. Users must provide the appropriate CallbackHandler classes for their specific LDAP implementation.
Example 9.4. Setting Up SASL Authentication in JGroups
<SASL mech="DIGEST-MD5"
client_name="node_user"
client_password="node_password"
server_callback_handler_class="org.example.infinispan.security.JGroupsSaslServerCallbackHandler"
client_callback_handler_class="org.example.infinispan.security.JGroupsSaslClientCallbackHandler"
sasl_props="com.sun.security.sasl.digest.realm=test_realm" />
The above example uses the
DIGEST-MD5 mechanism. Each node must declare the user and password it will use when joining the cluster.
Important
The SASL protocol must be placed before the GMS protocol in order for authentication to take effect.
The following example demonstrates how to implement a
CallbackHandler class. In this example, login and password are checked against values provided via Java properties when JBoss Data Grid is started, and authorization is checked against role which is defined in the class ("test_user").
Example 9.5. Callback Handler Class
public class SaslPropAuthUserCallbackHandler implements CallbackHandler {
private static final String APPROVED_USER = "test_user";
private final String name;
private final char[] password;
private final String realm;
public SaslPropAuthUserCallbackHandler() {
this.name = System.getProperty("sasl.username");
this.password = System.getProperty("sasl.password").toCharArray();
this.realm = System.getProperty("sasl.realm");
}
@Override
public void handle(Callback[] callbacks) throws IOException, UnsupportedCallbackException {
for (Callback callback : callbacks) {
if (callback instanceof PasswordCallback) {
((PasswordCallback) callback).setPassword(password);
} else if (callback instanceof NameCallback) {
((NameCallback) callback).setName(name);
} else if (callback instanceof AuthorizeCallback) {
AuthorizeCallback authorizeCallback = (AuthorizeCallback) callback;
if (APPROVED_USER.equals(authorizeCallback.getAuthorizationID())) {
authorizeCallback.setAuthorized(true);
} else {
authorizeCallback.setAuthorized(false);
}
} else if (callback instanceof RealmCallback) {
RealmCallback realmCallback = (RealmCallback) callback;
realmCallback.setText(realm);
} else {
throw new UnsupportedCallbackException(callback);
}
}
}
}
For authentication, specify the
javax.security.auth.callback.NameCallback and javax.security.auth.callback.PasswordCallback callbacks
For authorization, specify the callbacks required for authentication, as well as specifying the
javax.security.sasl.AuthorizeCallback callback.
9.2.1. Configure Node Authentication for Library Mode (DIGEST-MD5)
The behavior of a node differs depending on whether it is the coordinator node or any other node. The coordinator acts as the SASL server, with the joining or merging nodes behaving as SASL clients. When using the DIGEST-MD5 mechanism in Library mode, the server and client callback must be specified so that the server and client are aware of how to obtain the credentials. Therefore, two
CallbackHandlers are required:
- The
server_callback_handler_classis used by the coordinator. - The
client_callback_handler_classis used by other nodes.
The following example demonstrates these
CallbackHandlers.
Example 9.6. Callback Handlers
<SASL mech="DIGEST-MD5"
client_name="node_name"
client_password="node_password"
client_callback_handler_class="${CLIENT_CALLBACK_HANDLER_IN_CLASSPATH}"
server_callback_handler_class="${SERVER_CALLBACK_HANDLER_IN_CLASSPATH}"
sasl_props="com.sun.security.sasl.digest.realm=test_realm"
/>
JGroups is designed so that all nodes are able to act as coordinator or client depending on cluster behavior, so if the current coordinator node goes down, the next node in the succession chain will become the coordinator. Given this behavior, both server and client callback handlers must be identified within SASL for Red Hat JBoss Data Grid implementations.
9.2.2. Configure Node Authentication for Library Mode (GSSAPI)
When performing node authentication in Library mode using the GSSAPI mechanism, the
login_module_name parameter must be specified instead of callback.
This login module is used to obtain a valid Kerberos ticket, which is used to authenticate a client to the server. The
server_name must also be specified, as the client principal is constructed as jgroups/$server_name@REALM.
Example 9.7. Specifying the login module and server on the coordinator node
<SASL mech="GSSAPI"
server_name="node0/clustered"
login_module_name="krb-node0"
server_callback_handler_class="org.infinispan.test.integration.security.utils.SaslPropCallbackHandler" />
On the coordinator node, the
server_callback_handler_class must be specified for node authorization. This will determine if the authenticated joining node has permission to join the cluster.
Note
The server principal is always constructed as
jgroups/server_name, therefore the server principal in Kerberos must also be jgroups/server_name. For example, if the server name in Kerberos is jgroups/node1/mycache, then the server name must be node1/mycache.
9.2.3. Node Authorization in Library Mode
The
SASL protocol in JGroups is concerned only with the authentication process. To implement node authorization, you can do so within the server callback handler by throwing an Exception.
The following example demonstrates this.
Example 9.8. Implementing Node Authorization
public class AuthorizingServerCallbackHandler implements CallbackHandler {
@Override
public void handle(Callback[] callbacks) throws IOException,
UnsupportedCallbackException {
for (Callback callback : callbacks) {
...
if (callback instanceof AuthorizeCallback) {
AuthorizeCallback acb = (AuthorizeCallback) callback;
if (!"myclusterrole".equals(acb.getAuthenticationID()))) {
throw new SecurityException("Unauthorized node " +user);
}
...
}
}
}9.3. JGroups ENCRYPT
JGroups includes the
ENCRYPT protocol to provide encryption for cluster traffic.
By default, encryption only encrypts the message body; it does not encrypt message headers. To encrypt the entire message, including all headers, as well as destination and source addresses, the property
encrypt_entire_message must be true. ENCRYPT must also be below any protocols with headers that must be encrypted.
The
ENCRYPT layer is used to encrypt and decrypt communication in JGroups. The JGroups ENCRYPT protocol can be used in two ways:
- Configured with a secretKey in a keystore.
- Configured with algorithms and key sizes.
Each message is identified as encrypted with a specific encryption header identifying the encrypt header and an MD5 digest identifying the version of the key being used to encrypt and decrypt messages.
9.3.1. ENCRYPT Configured with a secretKey in a Key Store
The
ENCRYPT class can be configured with a secretKey in a keystore so it is usable at any layer in JGroups without requiring a coordinator. This also provides protection against passive monitoring without the complexity of key exchange.
This method can be used by inserting the encryption layer at any point in the JGroups stack, which will encrypt all events of a type MSG that have a non-nill message buffer. The following is an example of the entry in this form:
<ENCRYPT key_store_name="defaultStore.keystore" store_password="${VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::ENCRYPTED_VALUE}" alias="myKey"/>
The secretKey must be already generated in a keystore file in order to use the
ENCRYPT layer in this manner. The directory containing the keystore file must be on the application classpath.
Note
The secretKey keystore file cannot be created using the keytool application shipped with JDK. The
KeyStoreGenerator java file is included in the demo package that can be used to generate a suitable keystore.
9.3.2. ENCRYPT Using a Key Store
ENCRYPT uses store type JCEKS. To generate a keystore compatible with JCEKS, use the following command line options:
$ keytool -genseckey -alias myKey -keypass changeit -storepass changeit -keyalg Blowfish -keysize 56 -keystore defaultStore.keystore -storetype JCEKS
ENCRYPT can then be configured by adding the following information to the JGroups file used by the application.
<ENCRYPT key_store_name="defaultStore.keystore"
store_password="${VAULT::VAULT_BLOCK::ATTRIBUTE_NAME::ENCRYPTED_VALUE}"
alias="myKey"/>
Standard Java properties can also be used in the configuration, and it is possible to pass the path to JGroups configuration via the
-D option during start up.
The default, pre-configured JGroups files are packaged in
infinispan-embedded.jar, alternatively, you can create your own configuration file. See the Configure JGroups (Library Mode) section in the Red Hat JBoss Data Grid Administration and Configuration Guide for instructions on how to set up JBoss Data Grid to use custom JGroups configurations in library mode.
In Remote Client-Server mode, the JGroups configuration is part of the main server configuration file.
Note
The
defaultStore.keystore must be found in the classpath.
9.3.3. ENCRYPT Configured with Algorithms and Key Sizes
In this encryption mode, the coordinator selects the secretKey and distributes it to all peers. There is no keystore, and keys are distributed using a public/private key exchange. Instead, encryption occurs as follows:
- The secret key is generated and distributed by the controller.
- When a view change occurs, a peer requests the secret key by sending a key request with its own public key.
- The controller encrypts the secret key with the public key, and sends it back to the peer.
- The peer then decrypts and installs the key as its own secret key.
In this mode, the
ENCRYPT layer must be placed above the GMS protocol in the configuration.
Example 9.9. ENCRYPT Layer
<config ... >
<UDP />
<PING />
<MERGE2 />
<FD />
<VERIFY_SUSPECT />
<ENCRYPT encrypt_entire_message="false"
sym_init="128" sym_algorithm="AES/ECB/PKCS5Padding"
asym_init="512" asym_algorithm="RSA"/>
<pbcast.NAKACK />
<UNICAST />
<pbcast.STABLE />
<FRAG2 />
<pbcast.GMS />
</config>
In the provided example, the sequence numbers for the
NAKACK and UNICAST protocols will be encrypted.
View changes that identify a new controller result in a new session key being generated and distributed to all peers. This is a substantial overhead in an application with high peer churn.
When encrypting an entire message, the message must be marshalled into a byte buffer before being encrypted, resulting in decreased performance.
9.3.4. ENCRYPT Configuration Parameters
The following table provides configuration parameters for the
ENCRYPT JGroups protocol:
Table 9.1. Configuration Parameters
| Name | Description |
|---|---|
| alias | Alias used for recovering the key. Change the default. |
| asymAlgorithm | Cipher engine transformation for asymmetric algorithm. Default is RSA. |
| asymInit | Initial public/private key length. Default is 512. |
| asymProvider | Cryptographic Service Provider. Default is Bouncy Castle Provider. |
| encrypt_entire_message | |
| id | Give the protocol a different ID if needed so we can have multiple instances of it in the same stack. |
| keyPassword | Password for recovering the key. Change the default. |
| keyStoreName | File on classpath that contains keystore repository. |
| level | Sets the logger level (see javadocs). |
| name | Give the protocol a different name if needed so we can have multiple instances of it in the same stack. |
| stats | Determines whether to collect statistics (and expose them via JMX). Default is true. |
| storePassword | Password used to check the integrity/unlock the keystore. Change the default. It is recommended that passwords are stored using Vault. |
| symAlgorithm | Cipher engine transformation for symmetric algorithm. Default is AES. |
| symInit | Initial key length for matching symmetric algorithm. Default is 128. |
Part III. Advanced Features in Red Hat JBoss Data Grid
Red Hat JBoss Data Grid includes some advanced features. Some of these features are listed in the JBoss Data Grid Administration and Configuration Guide with instructions for a basic configuration. The JBoss Data Grid Developer Guide explores these features and others in more detail and with instructions for more advanced usage.
The advanced features explored in this guide are as follows:
- Transactions
- Marshalling
- Listeners and Notifications
- The Infinispan CDI Module
- MapReduce
- Distributed Execution
- Interoperability and Compatibility Mode
Chapter 10. Transactions
10.1. About Java Transaction API
Red Hat JBoss Data Grid supports configuring, use of, and participation in Java Transaction API (JTA) compliant transactions.
JBoss Data Grid does the following for each cache operation:
- First, it retrieves the transactions currently associated with the thread.
- If not already done, it registers an
XAResourcewith the transaction manager to receive notifications when a transaction is committed or rolled back.
10.2. Transactions Spanning Multiple Cache Instances
Each cache operates as a separate, standalone Java Transaction API (JTA) resource. However, components can be internally shared by Red Hat JBoss Data Grid for optimization, but this sharing does not affect how caches interact with a Java Transaction API (JTA) Manager.
10.3. The Transaction Manager
Use the following to obtain the TransactionManager from the cache:
TransactionManager tm = cache.getAdvancedCache().getTransactionManager();
To execute a sequence of operations within transaction, wrap these with calls to methods begin() and commit() or rollback() on the TransactionManager:
Example 10.1. Performing Operations
tm.begin();
Object value = cache.get("A");
cache.remove("A");
Object prev = cache.put("B", value);
if (prev == null)
tm.commit();
else
tm.rollback();Note
If a cache method returns a CacheException (or a subclass of the CacheException) within the scope of a JTA transaction, the transaction is automatically marked to be rolled back.
To obtain a reference to a Red Hat JBoss Data Grid XAResource, use the following API:
XAResource xar = cache.getAdvancedCache().getXAResource();
10.4. About JTA Transaction Manager Lookup Classes
In order to execute a cache operation, the cache requires a reference to the environment's Transaction Manager. Configure the cache with the class name that belongs to an implementation of the
TransactionManagerLookup interface. When initialized, the cache creates an instance of the specified class and invokes its getTransactionManager() method to locate and return a reference to the Transaction Manager.
Table 10.1. Transaction Manager Lookup Classes
| Class Name | Details |
|---|---|
| org.infinispan.transaction.lookup.DummyTransactionManagerLookup | Used primarily for testing environments. This testing transaction manager is not for use in a production environment and is severely limited in terms of functionality, specifically for concurrent transactions and recovery. |
| org.infinispan.transaction.lookup.JBossStandaloneJTAManagerLookup | It is a fully functional JBoss Transactions based transaction manager that overcomes the functionality limits of the DummyTransactionManager. |
| org.infinispan.transaction.lookup.GenericTransactionManagerLookup | GenericTransactionManagerLookup is used by default when no transaction lookup class is specified. This lookup class is recommended when using JBoss Data Grid with Java EE-compatible environment that provides a TransactionManager interface, and is capable of locating the Transaction Manager in most Java EE application servers. If no transaction manager is located, it defaults to DummyTransactionManager. |
It is important to note that when using Red Hat JBoss Data Grid with Tomcat or an ordinary Java Virtual Machine (JVM), the recommended Transaction Manager Lookup class is
JBossStandaloneJTAManagerLookup, which uses JBoss Transactions.
Chapter 11. Marshalling
Marshalling is the process of converting Java objects into a format that is transferable over the wire. Unmarshalling is the reversal of this process where data read from a wire format is converted into Java objects.
Red Hat JBoss Data Grid uses marshalling and unmarshalling to:
- transform data for relay to other JBoss Data Grid nodes within the cluster.
- transform data to be stored in underlying cache stores.
11.1. About Marshalling Framework
Red Hat JBoss Data Grid uses the JBoss Marshalling Framework to marshall and unmarshall Java POJOs. Using the JBoss Marshalling Framework offers a significant performance benefit, and is therefore used instead of Java Serialization. Additionally, the JBoss Marshalling Framework can efficiently marshall Java POJOs, including Java classes.
The Java Marshalling Framework uses high performance
java.io.ObjectOutput and java.io.ObjectInput implementations compared to the standard java.io.ObjectOutputStream and java.io.ObjectInputStream.
11.2. Support for Non-Serializable Objects
A common user concern is whether Red Hat JBoss Data Grid supports the storage of non-serializable objects. In JBoss Data Grid, marshalling is supported for non-serializable key-value objects; users can provide externalizer implementations for non-serializable objects.
If you are unable to retrofit
Serializable or Externalizable support into your classes, you could (as an example) use XStream to convert the non-serializable objects into a String that can be stored in JBoss Data Grid.
Note
XStream slows down the process of storing key-value objects due to the required XML transformations.
11.3. Hot Rod and Marshalling
In Remote Client-Server mode, marshalling occurs both on the Red Hat JBoss Data Grid server and the client levels, but to varying degrees.
- All data stored by clients on the JBoss Data Grid server are provided either as a byte array, or in a primitive format that is marshalling compatible for JBoss Data Grid.On the server side of JBoss Data Grid, marshalling occurs where the data stored in primitive format are converted into byte array and replicated around the cluster or stored to a cache store. No marshalling configuration is required on the server side of JBoss Data Grid.
- At the client level, marshalling must have a
Marshallerconfiguration element specified in the RemoteCacheManager configuration in order to serialize and deserialize POJOs.Due to Hot Rod's binary nature, it relies on marshalling to transform POJOs, specifically keys or values, into byte array.
11.4. Configuring the Marshaller using the RemoteCacheManager
A Marshaller is specified using the
marshaller configuration element in the RemoteCacheManager, the value of which must be the name of the class implementing the Marshaller interface. The default value for this property is org.infinispan.commons.marshall.jboss.GenericJBossMarshaller.
The following procedure describes how to define a Marshaller to use with RemoteCacheManager.
Procedure 11.1. Define a Marshaller
Create a ConfigurationBuilder
Create a ConfigurationBuilder and configure it with the required settings.ConfigurationBuilder builder = new ConfigurationBuilder(); //... (other configuration)
Add a Marshaller Class
Add a Marshaller class specification within the Marshaller method.builder.marshaller(GenericJBossMarshaller.class);
- Alternatively, specify a custom Marshaller instance.
builder.marshaller(new GenericJBossMarshaller());
Start the RemoteCacheManager
Build the configuration containing the Marshaller, and start a new RemoteCacheManager with it.Configuration configuration = builder.build(); RemoteCacheManager manager = new RemoteCacheManager(configuration);
At the client level, POJOs need to be either Serializable, Externalizable, or primitive types.
Note
The Hot Rod Java client does not support providing Externalizer instances to serialize POJOs. This is only available for JBoss Data Grid Library mode.
11.5. Troubleshooting
11.5.1. Marshalling Troubleshooting
In Red Hat JBoss Data Grid, the marshalling layer and JBoss Marshalling in particular, can produce errors when marshalling or unmarshalling a user object. The exception stack trace contains further information to help you debug the problem.
Example 11.1. Exception Stack Trace
java.io.NotSerializableException: java.lang.Object at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:857) at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:407) at org.infinispan.marshall.exts.ReplicableCommandExternalizer.writeObject(ReplicableCommandExternalizer.java:54) at org.infinispan.marshall.jboss.ConstantObjectTable$ExternalizerAdapter.writeObject(ConstantObjectTable.java:267) at org.jboss.marshalling.river.RiverMarshaller.doWriteObject(RiverMarshaller.java:143) at org.jboss.marshalling.AbstractMarshaller.writeObject(AbstractMarshaller.java:407) at org.infinispan.marshall.jboss.JBossMarshaller.objectToObjectStream(JBossMarshaller.java:167) at org.infinispan.marshall.VersionAwareMarshaller.objectToBuffer(VersionAwareMarshaller.java:92) at org.infinispan.marshall.VersionAwareMarshaller.objectToByteBuffer(VersionAwareMarshaller.java:170) at org.infinispan.marshall.VersionAwareMarshallerTest.testNestedNonSerializable(VersionAwareMarshallerTest.java:415) Caused by: an exception which occurred: in object java.lang.Object@b40ec4 in object org.infinispan.commands.write.PutKeyValueCommand@df661da7 ... Removed 22 stack frames
Messages starting with
in object and stack traces are read in the same way: the highest in object message is the innermost one and the outermost in object message is the lowest.
The provided example indicates that a
java.lang.Object instance within an org.infinispan.commands.write.PutKeyValueCommand instance cannot be serialized because java.lang.Object@b40ec4 is not serializable.
However, if the
DEBUG or TRACE logging levels are enabled, marshalling exceptions will contain toString() representations of objects in the stack trace. The following is an example that depicts such a scenario:
Example 11.2. Exceptions with Logging Levels Enabled
java.io.NotSerializableException: java.lang.Object
...
Caused by: an exception which occurred:
in object java.lang.Object@b40ec4
-> toString = java.lang.Object@b40ec4
in object org.infinispan.commands.write.PutKeyValueCommand@df661da7
-> toString = PutKeyValueCommand{key=k, value=java.lang.Object@b40ec4, putIfAbsent=false, lifespanMillis=0, maxIdleTimeMillis=0}
Displaying this level of information for unmarshalling exceptions is expensive in terms of resources. However, where possible, JBoss Data Grid displays class type information. The following example depicts such levels of information on display:
Example 11.3. Unmarshalling Exceptions
java.io.IOException: Injected failue! at org.infinispan.marshall.VersionAwareMarshallerTest$1.readExternal(VersionAwareMarshallerTest.java:426) at org.jboss.marshalling.river.RiverUnmarshaller.doReadNewObject(RiverUnmarshaller.java:1172) at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:273) at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:210) at org.jboss.marshalling.AbstractUnmarshaller.readObject(AbstractUnmarshaller.java:85) at org.infinispan.marshall.jboss.JBossMarshaller.objectFromObjectStream(JBossMarshaller.java:210) at org.infinispan.marshall.VersionAwareMarshaller.objectFromByteBuffer(VersionAwareMarshaller.java:104) at org.infinispan.marshall.VersionAwareMarshaller.objectFromByteBuffer(VersionAwareMarshaller.java:177) at org.infinispan.marshall.VersionAwareMarshallerTest.testErrorUnmarshalling(VersionAwareMarshallerTest.java:431) Caused by: an exception which occurred: in object of type org.infinispan.marshall.VersionAwareMarshallerTest$1
In the provided example, an
IOException was thrown when an instance of the inner class org.infinispan.marshall.VersionAwareMarshallerTest$1 is unmarshalled.
In a manner similar to marshalling exceptions, when
DEBUG or TRACE logging levels are enabled, the class type's classloader information is provided. An example of this classloader information is as follows:
Example 11.4. Classloader Information
java.io.IOException: Injected failue! ... Caused by: an exception which occurred: in object of type org.infinispan.marshall.VersionAwareMarshallerTest$1 -> classloader hierarchy: -> type classloader = sun.misc.Launcher$AppClassLoader@198dfaf ->...file:/opt/eclipse/configuration/org.eclipse.osgi/bundles/285/1/.cp/eclipse-testng.jar ->...file:/opt/eclipse/configuration/org.eclipse.osgi/bundles/285/1/.cp/lib/testng-jdk15.jar ->...file:/home/galder/jboss/infinispan/code/trunk/core/target/test-classes/ ->...file:/home/galder/jboss/infinispan/code/trunk/core/target/classes/ ->...file:/home/galder/.m2/repository/org/testng/testng/5.9/testng-5.9-jdk15.jar ->...file:/home/galder/.m2/repository/net/jcip/jcip-annotations/1.0/jcip-annotations-1.0.jar ->...file:/home/galder/.m2/repository/org/easymock/easymockclassextension/2.4/easymockclassextension-2.4.jar ->...file:/home/galder/.m2/repository/org/easymock/easymock/2.4/easymock-2.4.jar ->...file:/home/galder/.m2/repository/cglib/cglib-nodep/2.1_3/cglib-nodep-2.1_3.jar ->...file:/home/galder/.m2/repository/javax/xml/bind/jaxb-api/2.1/jaxb-api-2.1.jar ->...file:/home/galder/.m2/repository/javax/xml/stream/stax-api/1.0-2/stax-api-1.0-2.jar ->...file:/home/galder/.m2/repository/javax/activation/activation/1.1/activation-1.1.jar ->...file:/home/galder/.m2/repository/jgroups/jgroups/2.8.0.CR1/jgroups-2.8.0.CR1.jar ->...file:/home/galder/.m2/repository/org/jboss/javaee/jboss-transaction-api/1.0.1.GA/jboss-transaction-api-1.0.1.GA.jar ->...file:/home/galder/.m2/repository/org/jboss/marshalling/river/1.2.0.CR4-SNAPSHOT/river-1.2.0.CR4-SNAPSHOT.jar ->...file:/home/galder/.m2/repository/org/jboss/marshalling/marshalling-api/1.2.0.CR4-SNAPSHOT/marshalling-api-1.2.0.CR4-SNAPSHOT.jar ->...file:/home/galder/.m2/repository/org/jboss/jboss-common-core/2.2.14.GA/jboss-common-core-2.2.14.GA.jar ->...file:/home/galder/.m2/repository/org/jboss/logging/jboss-logging-spi/2.0.5.GA/jboss-logging-spi-2.0.5.GA.jar ->...file:/home/galder/.m2/repository/log4j/log4j/1.2.14/log4j-1.2.14.jar ->...file:/home/galder/.m2/repository/com/thoughtworks/xstream/xstream/1.2/xstream-1.2.jar ->...file:/home/galder/.m2/repository/xpp3/xpp3_min/1.1.3.4.O/xpp3_min-1.1.3.4.O.jar ->...file:/home/galder/.m2/repository/com/sun/xml/bind/jaxb-impl/2.1.3/jaxb-impl-2.1.3.jar -> parent classloader = sun.misc.Launcher$ExtClassLoader@1858610 ->...file:/usr/java/jdk1.5.0_19/jre/lib/ext/localedata.jar ->...file:/usr/java/jdk1.5.0_19/jre/lib/ext/sunpkcs11.jar ->...file:/usr/java/jdk1.5.0_19/jre/lib/ext/sunjce_provider.jar ->...file:/usr/java/jdk1.5.0_19/jre/lib/ext/dnsns.jar ... Removed 22 stack frames
11.5.2. Other Marshalling Related Issues
Issues and exceptions related to Marshalling can also appear in different contexts, for example during the State transfer with
EOFException. During a state transfer, if an EOFException is logged that states that the state receiver has Read past end of file, this can be dealt with depending on whether the state provider encounters an error when generating the state. For example, if the state provider is currently providing a state to a node, when another node requests a state, the state generator log can contain:
Example 11.5. State Generator Log
2010-12-09 10:26:21,533 20267 ERROR [org.infinispan.remoting.transport.jgroups.JGroupsTransport] (STREAMING_STATE_TRANSFER-sender-1,Infinispan-Cluster,NodeJ-2368:) Caught while responding to state transfer request
org.infinispan.statetransfer.StateTransferException: java.util.concurrent.TimeoutException: Could not obtain exclusive processing lock
at org.infinispan.statetransfer.StateTransferManagerImpl.generateState(StateTransferManagerImpl.java:175)
at org.infinispan.remoting.InboundInvocationHandlerImpl.generateState(InboundInvocationHandlerImpl.java:119)
at org.infinispan.remoting.transport.jgroups.JGroupsTransport.getState(JGroupsTransport.java:586)
at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.handleUpEvent(MessageDispatcher.java:691)
at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:772)
at org.jgroups.JChannel.up(JChannel.java:1465)
at org.jgroups.stack.ProtocolStack.up(ProtocolStack.java:954)
at org.jgroups.protocols.pbcast.FLUSH.up(FLUSH.java:478)
at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER$StateProviderHandler.process(STREAMING_STATE_TRANSFER.java:653)
at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER$StateProviderThreadSpawner$1.run(STREAMING_STATE_TRANSFER.java:582)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)
Caused by: java.util.concurrent.TimeoutException: Could not obtain exclusive processing lock
at org.infinispan.remoting.transport.jgroups.JGroupsDistSync.acquireProcessingLock(JGroupsDistSync.java:71)
at org.infinispan.statetransfer.StateTransferManagerImpl.generateTransactionLog(StateTransferManagerImpl.java:202)
at org.infinispan.statetransfer.StateTransferManagerImpl.generateState(StateTransferManagerImpl.java:165)
... 12 more
In logs, you can also spot exceptions which seems to be related to marshaling. However, the root cause of the exception can be different. The implication of this exception is that the state generator was unable to generate the transaction log hence the output it was writing in now closed. In such a situation, the state receiver will often log an
EOFException, displayed as follows, when failing to read the transaction log that was not written by the sender:
Example 11.6. EOFException
2010-12-09 10:26:21,535 20269 TRACE [org.infinispan.marshall.VersionAwareMarshaller] (Incoming-2,Infinispan-Cluster,NodeI-38030:) Log exception reported
java.io.EOFException: Read past end of file
at org.jboss.marshalling.AbstractUnmarshaller.eofOnRead(AbstractUnmarshaller.java:184)
at org.jboss.marshalling.AbstractUnmarshaller.readUnsignedByteDirect(AbstractUnmarshaller.java:319)
at org.jboss.marshalling.AbstractUnmarshaller.readUnsignedByte(AbstractUnmarshaller.java:280)
at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:207)
at org.jboss.marshalling.AbstractUnmarshaller.readObject(AbstractUnmarshaller.java:85)
at org.infinispan.marshall.jboss.GenericJBossMarshaller.objectFromObjectStream(GenericJBossMarshaller.java:175)
at org.infinispan.marshall.VersionAwareMarshaller.objectFromObjectStream(VersionAwareMarshaller.java:184)
at org.infinispan.statetransfer.StateTransferManagerImpl.processCommitLog(StateTransferManagerImpl.java:228)
at org.infinispan.statetransfer.StateTransferManagerImpl.applyTransactionLog(StateTransferManagerImpl.java:250)
at org.infinispan.statetransfer.StateTransferManagerImpl.applyState(StateTransferManagerImpl.java:320)
at org.infinispan.remoting.InboundInvocationHandlerImpl.applyState(InboundInvocationHandlerImpl.java:102)
at org.infinispan.remoting.transport.jgroups.JGroupsTransport.setState(JGroupsTransport.java:603)
...
When this error occurs, the state receiver attempts the operation every few seconds until it is successful. In most cases, after the first attempt, the state generator has already finished processing the second node and is fully receptive to the state, as expected.
Chapter 12. Listeners and Notifications
12.1. The Notification/Listener API
Red Hat JBoss Data Grid provides a listener API that provides notifications for events as they occur. Clients can choose to register with the listener API for relevant notifications. This annotation-driven API operates on cache-level events and cache manager-level events.
12.2. Listener Notifications
Each cache event triggers a notification that is dispatched to listeners. A listener is a simple POJO annotated with
@Listener. A Listenable is an interface that denotes that the implementation can have listeners attached to it. Each listener is registered using methods defined in the Listenable.
A listener can be attached to both the cache and Cache Manager to allow them to receive cache-level or cache manager-level notifications.
12.2.1. About Cache-level Notifications
In Red Hat JBoss Data Grid, cache-level events occur on a per-cache basis, and are global and cluster-wide. Examples of cache-level events include the addition, removal and modification of entries, which trigger notifications to listeners registered on the relevant cache.
12.2.2. Cache Manager-level Notifications
Examples of events that occur in Red Hat JBoss Data Grid at the cache manager-level are:
- Nodes joining or leaving a cluster;
- The starting and stopping of caches
Cache manager-level events are located globally and used cluster-wide, but are restricted to events within caches created by a single cache manager.
12.2.3. About Synchronous and Asynchronous Notifications
By default, notifications in Red Hat JBoss Data Grid are dispatched in the same thread that generates the event. Therefore the listener must be written in a way that does not block or prevent the thread's progression.
Alternatively, the listener can be annotated as asynchronous, which dispatches notifications in a separate thread and prevents blocking the operations of the original thread.
Annotate listeners using the following:
@Listener (sync = false)
public class MyAsyncListener { .... }
Use the
<asyncListenerExecutor/> element in the configuration file to tune the thread pool that is used to dispatch asynchronous notifications.
12.3. Modifying Cache Entries
After the cache entry has been created, the cache entry can be modified programmatically.
12.3.1. Cache Entry Modified Listener Configuration
In a cache entry modified listener event, The
getValue() method's behavior is specific to whether the callback is triggered before or after the actual operation has been performed. For example, if event.isPre() is true, then event.getValue() would return the old value, prior to modification. If event.isPre() is false, then event.getValue() would return new value. If the event is creating and inserting a new entry, the old value would be null. For more information about isPre(), see the Red Hat JBoss Data Grid API Documentation's listing for the org.infinispan.notifications.cachelistener.event package.
Listeners can only be configured programmatically by using the methods exposed by the Listenable and FilteringListenable interfaces (which the Cache object implements).
12.3.2. Listener Example
The following example defines a listener in Red Hat JBoss Data Grid that prints some information each time a new entry is added to the cache:
Example 12.1. Configuring a Listener
@Listener
public class PrintWhenAdded {
@CacheEntryCreated
public void print(CacheEntryCreatedEvent event) {
System.out.println("New entry " + event.getKey() + " created in the cache");
}
}12.3.3. Cache Entry Modified Listener Example
The following example defines a listener in Red Hat JBoss Data Grid that prints some information each time a cache entry is modified:
Example 12.2. Modified Listener
@Listener
public class PrintWhenModified {
@CacheEntryModified
public void print(CacheEntryModifiedEvent event) {
System.out.println("Cache entry modified. Details = " + event");
}
}12.4. NotifyingFutures
Methods in Red Hat JBoss Data Grid do not return Java Development Kit (JDK)
Futures, but a sub-interface known as a NotifyingFuture. Unlike a JDK Future, a listener can be attached to a NotifyingFuture to notify the user about a completed future.
Note
NotifyingFutures are only available in JBoss Data Grid Library mode.
12.4.1. NotifyingFutures Example
The following is an example depicting how to use
NotifyingFutures in Red Hat JBoss Data Grid:
Example 12.3. Configuring NotifyingFutures
FutureListener futureListener = new FutureListener() {
public void futureDone(Future future) {
try {
future.get();
} catch (Exception e) {
// Future did not complete successfully
System.out.println("Help!");
}
}
};
cache.putAsync("key", "value").attachListener(futureListener);Chapter 13. The Infinispan CDI Module
Infinispan includes Context and Dependency Injection (CDI) in the
infinispan-cdi module. The infinispan-cdi module offers:
- Configuration and injection using the Cache API.
- A bridge between the cache listeners and the CDI event system.
- Partial support for the JCACHE caching annotations.
13.1. Using Infinispan CDI
13.1.1. Infinispan CDI Prerequisites
The following is a list of prerequisites to use the Infinispan CDI module with Red Hat JBoss Data Grid:
- Ensure that the most recent version of the infinispan-cdi module is used.
- Ensure that the correct dependency information is set.
13.1.2. Set the CDI Maven Dependency
Add the following dependency information to the
pom.xml file in your maven project:
<dependencies>
...
<dependency>
<groupId>org.infinispan</groupId>
<artifactId>infinispan-cdi</artifactId>
<version>${infinispan.version}</version>
</dependency>
...
</dependencies>
If Maven is not in use, the
infinispan-cdi jar file is available at modules/infinispan-cdi in the ZIP distribution.
13.2. Using the Infinispan CDI Module
The Infinispan CDI module can be used for the following purposes:
- To configure and inject Infinispan caches into CDI Beans and Java EE components.
- To configure cache managers.
- To control storage and retrieval using CDI annotations.
13.2.1. Configure and Inject Infinispan Caches
13.2.1.1. Inject an Infinispan Cache
An Infinispan cache is one of the multiple components that can be injected into the project's CDI beans.
The following code snippet illustrates how to inject a cache instance into the CDI bean:
public class MyCDIBean {
@Inject
Cache<String, String> cache;
}13.2.1.2. Inject a Remote Infinispan Cache
The code snippet to inject a normal cache is slightly modified to inject a remote Infinispan cache, as follows:
public class MyCDIBean {
@Inject
RemoteCache<String, String> remoteCache;
}13.2.1.3. Set the Injection's Target Cache
The following are the three steps to set an injection's target cache:
- Create a qualifier annotation.
- Add a producer class.
- Inject the desired class.
13.2.1.3.1. Create a Qualifier Annotation
To use CDI to return a specific cache, create custom cache qualifier annotations as follows:
Example 13.1. Custom Cache Qualifier
@javax.inject.Qualifier
@Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface SmallCache {}
Use the created
@SmallCache qualifier to specify how to create specific caches.
13.2.1.3.2. Add a Producer Class
The following code snippet illustrates how the
@SmallCache qualifier (created in the previous step) specifies a way to create a cache:
Example 13.2. Using the @SmallCache Qualifier
import org.infinispan.configuration.cache.Configuration;
import org.infinispan.configuration.cache.ConfigurationBuilder;
import org.infinispan.cdi.ConfigureCache;
import javax.enterprise.inject.Proces;
public class CacheCreator {
@ConfigureCache("smallcache")
@SmallCache
@Produces
public Configuration specialCacheCfg() {
return new ConfigurationBuilder()
.eviction()
.strategy(EvictionStrategy.LRU)
.maxEntries(10)
.build();
}
}
The elements in the code snippet are:
@ConfigureCachespecifies the name of the cache.@SmallCacheis the cache qualifier.
13.2.1.3.3. Inject the Desired Class
Use the
@SmallCache qualifier and the new producer class to inject a specific cache into the CDI bean as follows:
public class MyCDIBean {
@Inject @SmallCache
Cache<String, String> mySmallCache;
}13.2.2. Configure Cache Managers with CDI
A Red Hat JBoss Data Grid Cache Manager (both embedded and remote) can be configured using CDI. Whether configuring an embedded or remote cache manager, the first step is to specify a default configuration that is annotated to act as a producer.
13.2.2.1. Specify the Default Configuration
Specify a method annotated as a producer for the Red Hat JBoss Data Grid configuration object to replace the default Infinispan Configuration. The following sample configuration illustrates this step:
Example 13.3. Specifying the Default Configuration
public class Config {
@Produces
public Configuration defaultEmbeddedConfiguration () {
return new ConfigurationBuilder()
.eviction()
.strategy(EvictionStrategy.LRU)
.maxEntries(100)
.build();
}
}Note
CDI adds a
@Default qualifier if no other qualifiers are provided.
If a
@Produces annotation is placed in a method that returns a Configuration instance, the method is invoked when a Configuration object is required.
In the provided example configuration, the method creates a new Configuration object which is subsequently configured and returned.
13.2.2.2. Override the Creation of the Embedded Cache Manager
Prerequisites
Creating Non Clustered Caches
After a producer method is annotated, this method will be called when creating an EmbeddedCacheManager, as follows:
Example 13.4. Create a Non Clustered Cache
public class Config {
@Produces
@ApplicationScoped
public EmbeddedCacheManager defaultEmbeddedCacheManager() {
Configuration cfg = new ConfigurationBuilder()
.eviction()
.strategy(EvictionStrategy.LRU)
.maxEntries(150)
.build();
return new DefaultCacheManager(cfg);
}
}
The
@ApplicationScoped annotation specifies that the method is only called once.
Creating Clustered Caches
The following configuration can be used to create an EmbeddedCacheManager that can create clustered caches.
Example 13.5. Create Clustered Caches
public class Config {
@Produces
@ApplicationScoped
public EmbeddedCacheManager defaultClusteredCacheManager() {
GlobalConfiguration g = new GlobalConfigurationBuilder()
.clusteredDefault()
.transport()
.clusterName("InfinispanCluster")
.build();
Configuration cfg = new ConfigurationBuilder()
.eviction()
.strategy(EvictionStrategy.LRU)
.maxEntries(150)
.build();
return new DefaultCacheManager(g, cfg);
}
}Invoke the Method to Generate an EmbeddedCacheManager
The method annotated with @Produces in the non clustered method generates Configuration objects. The methods in the clustered cache example annonated with @Produces generate EmbeddedCacheManager objects.
Add an injection as follows in your CDI Bean to invoke the appropriate annotated method. This generates
EmbeddedCacheManager and injects it into the code at runtime.
Example 13.6. Generate an EmbeddedCacheManager
... @Inject EmbeddedCacheManager cacheManager; ...
13.2.2.3. Configure a Remote Cache Manager
The
RemoteCacheManager is configured in a manner similar to EmbeddedCacheManagers, as follows:
Example 13.7. Configuring the Remote Cache Manager
public class Config {
@Produces
@ApplicationScoped
public RemoteCacheManager defaultRemoteCacheManager() {
Configuration conf = new ConfigurationBuilder().addServer().host(ADDRESS).port(PORT).build();
return new RemoteCacheManager(conf);
}
}}13.2.2.4. Configure Multiple Cache Managers with a Single Class
A single class can be used to configure multiple cache managers and remote cache managers based on the created qualifiers. An example of this is as follows:
Example 13.8. Configure Multiple Cache Managers
public class Config {
@Produces
@ApplicationScoped
public org.infinispan.manager.EmbeddedCacheManager
defaultEmbeddedCacheManager() {
Configuration cfg = new ConfigurationBuilder()
.eviction()
.strategy(EvictionStrategy.LRU)
.maxEntries(150)
.build();
return new DefaultCacheManager(cfg);
}
@Produces
@ApplicationScoped
@DefaultClustered
public org.infinispan.manager.EmbeddedCacheManager
defaultClusteredCacheManager() {
GlobalConfiguration g = new GlobalConfigurationBuilder()
.clusteredDefault()
.transport()
.clusterName("InfinispanCluster")
.build();
Configuration cfg = new ConfigurationBuilder()
.eviction()
.strategy(EvictionStrategy.LRU)
.maxEntries(150)
.build();
return new DefaultCacheManager(g, cfg);
}
@Produces
@ApplicationScoped
@DefaultRemote
public RemoteCacheManager
defaultRemoteCacheManager() {
org.infinispan.client.hotrod.configuration.Configuration conf = new org.infinispan.client.hotrod.configuration.ConfigurationBuilder().addServer().host(ADDRESS).port(PORT).build();
return new RemoteCacheManager(conf);
}
@Produces
@ApplicationScoped
@RemoteCacheInDifferentDataCentre
public RemoteCacheManager newRemoteCacheManager() {
org.infinispan.client.hotrod.configuration.Configuration confid = new org.infinispan.client.hotrod.configuration.ConfigurationBuilder().addServer().host(ADDRESS_FAR_AWAY).port(PORT).build();
return new RemoteCacheManager(confid);
}
}13.2.3. Storage and Retrieval Using CDI Annotations
13.2.3.1. Configure Cache Annotations
Specific CDI annotations are accepted for the JCache (JSR-107) specification. All included annotations are located in the
javax.cache package.
The annotations intercept method calls on CDI beans and perform storage and retrieval tasks as a result of these interceptions.
13.2.3.2. Enable Cache Annotations
Interceptors can be added to the CDI bean archive using the
beans.xml file. Adding the following code adds interceptors such as the CacheResultInterceptor, CachePutInterceptor, CacheRemoveEntryInterceptor and the CacheRemoveAllInterceptor:
Example 13.9. Adding Interceptors
<beans xmlns="http://java.sun.som/xml/ns/javaee"
xmlns:xsi="http://www/w3/org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/beans_1_0.xsd" >
<interceptors>
<class>
org.infinispan.cdi.interceptor.CacheResultInterceptor
</class>
<class>
org.infinispan.cdi.interceptor.CachePutInterceptor
</class>
<class>
org.infinispan.cdi.interceptor.CacheRemoveEntryInterceptor
</class>
<class>
org.infinispan.cdi.interceptor.CacheRemoveAllInterceptor
</class>
</interceptors>
</beans>Note
The listed interceptors must appear in the
beans.xml file for Red Hat JBoss Data Grid to use javax.cache annotations.
13.2.3.3. Caching the Result of a Method Invocation
A common practice for time or resource intensive operations is to save the results in a cache for future access. The following code is an example of such an operation:
public String toCelsiusFormatted(float fahrenheit) {
return
NumberFormat.getInstance()
.format((fahrenheit * 5 / 9) - 32)
+ " degrees Celsius";
}
A common approach is to cache the results of this method call and to check the cache when the result is next required. The following is an example of a code snippet that looks up the result of such an operation in a cache. If the results are not found, the code snippet runs the
toCelsiusFormatted method again and stores the result in the cache.
float f = getTemperatureInFahrenheit();
Cache<Float, String>
fahrenheitToCelsiusCache = getCache();
String celsius =
fahrenheitToCelsiusCache = get(f);
if (celsius == null) {
celsius = toCelsiusFormatted(f);
fahrenheitToCelsiusCache.put(f, celsius);
}
In such cases, the Infinispan CDI module can be used to eliminate all the extra code in the related examples. Annotate the method with the
@CacheResult annotation instead, as follows:
@javax.cache.interceptor.CacheResult
public String toCelsiusFormatted(float fahrenheit) {
return NumberFormat.getInstance()
.format((fahrenheit * 5 / 9) - 32)
+ " degrees Celsius";
}
Due to the annotation, Infinispan checks the cache and if the results are not found, it invokes the
toCelsiusFormatted() method call.
Note
The Infinispan CDI module allows checking the cache for saved results, but this approach should be carefully considered before application. If the results of the call should always be fresh data, or if the cache reading requires a remote network lookup or deserialization from a cache loader, checking the cache before call method invocation can be counter productive.
13.2.3.3.1. Specify the Cache Used
Add the following optional attribute (
cacheName) to the @CacheResult annotation to specify the cache to check for results of the method call:
@CacheResult(cacheName = "mySpecialCache")
public String doSomething(String parameter) {
...
}13.2.3.3.2. Cache Keys for Cached Results
As a default, the
@CacheResult annotation creates a key for the results fetched from a cache. The key consists of a combination of all parameters in the relevant method.
Create a custom key using the
@CacheKey annotation as follows:
Example 13.10. Create a Custom Key
@CacheResult
public String doSomething
(@CacheKey String p1,
@CacheKey String p2,
String dontCare) {
...
}
In the specified example, only the values of
p1 and p2 are used to create the cache key. The value of dontCare is not used when determining the cache key.
13.2.3.3.3. Generate a Custom Key
Generate a custom key as follows:
import javax.cache.annotation.CacheKey;
import javax.cache.annotation.CacheKeyGenerator;
import javax.cache.annotation.CacheKeyInvocationContext;
import java.lang.annotation.Annotation;
public class MyCacheKeyGenerator implements CacheKeyGenerator {
@Override
public CacheKey generateCacheKey(CacheKeyInvocationContext<? extends Annotation> ctx) {
return new MyCacheKey(
ctx.getAllParameters()[0].getValue()
);
}
}
The listed method constructs a custom key. This key is passed as part of the value generated by the first parameter of the invocation context.
To specify the custom key generation scheme, add the optional parameter
cacheKeyGenerator to the @CacheResult annotation as follows:
@CacheResult(cacheKeyGenerator = MyCacheKeyGenerator.class)
public void doSomething(String p1, String p2) {
...
}
Using the provided method,
p1 contains the custom key.
13.2.4. Cache Operations
13.2.4.1. Update a Cache Entry
When the method that contains the
@CachePut annotation is invoked, a parameter (normally passed to the method annotated with @CacheValue) is stored in the cache.
Example 13.11. Sample @CachePut Annotated Method
import javax.cache.annotation.CachePut
@CachePut (cacheName = "personCache")
public void updatePerson
(@CacheKey long personId,
@CacheValue Person newPerson) {
...
}
Further customization is possible using
cacheName and cacheKeyGenerator in the @CachePut method. Additionally, some parameters in the invoked method may be annotated with @CacheKey to control key generation.
13.2.4.2. Remove an Entry from the Cache
The following is an example of a
@CacheRemoveEntry annotated method that is used to remove an entry from the cache:
Example 13.12. Removing an Entry from the Cache
import javax.cache.annotation.CacheRemoveEntry
@CacheRemoveEntry (cacheName = "cacheOfPeople")
public void changePersonName
(@CacheKey long personId,
string newName {
...
}
The annotation accepts the optional
cacheName and cacheKeyGenerator attributes.
13.2.4.3. Clear the Cache
Invoke the
@CacheRemoveAll method to clear all entries from the cache.
Example 13.13. Clear All Entries from the Cache with @CacheRemoveAll
import javax.cache.annotation.CacheResult
@CacheRemoveAll (cacheName = "statisticsCache")
public void resetStatistics() {
...
}
As displayed in the example, this annotation accepts an optional
cacheName attribute.
Chapter 14. MapReduce
The Red Hat JBoss Data Grid MapReduce model is an adaptation of Google's MapReduce model.
MapReduce is a programming model used to process and generate large data sets. It is typically used in distributed computing environments where nodes are clustered. In JBoss Data Grid, MapReduce allows transparent distributed processing of large amounts of data across the grid. It does this by performing computations locally where the data is stored whenever possible.
MapReduce uses the two distinct computational phases of map and reduce to process information requests through the data grid. The process occurs as follows:
- The user initiates a task on a cache instance, which runs on a cluster node (the master node).
- The master node receives the task input, divides the task, and sends tasks for map phase execution on the grid.
- Each node executes a
Mapperfunction on its input, and returns intermediate results back to the master node.- If the
useIntermediateSharedCacheparameter is set to"true", the map results are inserted in an intermediary cache, rather than being returned to the master node. - If a
Combinerhas been specified withtask.combinedWith(combiner), theCombineris called on theMapperresults and the combiner's results are returned to the master node or inserted in the intermediary cache.Note
Combiners are not required but can only be used when the function is both commutative (changing the order of the operands does not change the results) and associative (the order in which the operations are performed does not matter as long as the sequence of the operands is not changed). Combiners are advantageous to use because they can improve the speeds of MapReduceTask executions.
- The master node collects all intermediate results from the map phase and merges all intermediate values associated with the same intermediate key.
- If the
distributedReducePhaseparameter is set totrue, the merging of the intermediate values is done on each node, as theMapperorCombinerresults are inserted in the intermediary cache.The master node only receives the intermediate keys.
- The master node sends intermediate key/value pairs for reduction on the grid.
- If the
distributedReducePhaseparameter is set to"false", the reduction phase is executed only on the master node.
- The final results of the reduction phase are returned. Optionally specify the target cache for the results using the instructions in Section 14.1.2, “Specify the Target Cache”.
- If the
distributedReducePhaseparameter is set to"true", the master node running the task receives all results from the reduction phase and returns the final result to the MapReduce task initiator. - If no target cache is specified and no collator is specified (using
task.execute(Collator)), the result map is returned to the master node.
14.1. The MapReduce API
In Red Hat JBoss Data Grid, each MapReduce task has five main components:
MapperReducerCollatorMapReduceTaskCombiners
The
Mapper class implementation is a component of MapReduceTask, which is invoked once per input cache entry key/value pair. Map is a process of applying a given function to each element of a list, returning a list of results.
Each node in the JBoss Data Grid executes the
Mapper on a given cache entry key/value input pair. It then transforms this cache entry key/value pair into an intermediate key/value pair, which is emitted into the provided Collector instance.
Note
The MapReduceTask requires a Mapper and a Reducer but using a Collator or Combiner is optional.
Example 14.1. Executing the Mapper
public interface Mapper<KIn, VIn, KOut, VOut> extends Serializable {
/**
* Invoked once for each input cache entry KIn,VOut pair.
*/
void map(KIn key, VIn value, Collector<KOut, VOut> collector);
At this stage, for each output key there may be multiple output values. The multiple values must be reduced to a single value, and this is the task of the
Reducer. JBoss Data Grid's distributed execution environment creates one instance of Reducer per execution node.
Example 14.2. Reducer
public interface Reducer<KOut, VOut> extends Serializable {
/**
* Combines/reduces all intermediate values for a particular intermediate key to a single value.
* <p>
*
*/
VOut reduce(KOut reducedKey, Iterator<VOut> iter);
}
The same
Reducer interface is used for Combiners. A Combiner is similar to a Reducer, except that it must be able to work on partial results. The Combiner is executed on the results of the Mapper, on the same node, without considering the other nodes that might have generated values for the same intermediate key.
Note
Combiners are not required but can only be used when the function is both commutative (changing the order of the operands does not change the results) and associative (the order in which the operations are performed does not matter as long as the sequence of the operands is not changed). Combiners are advantageous to use because they can improve the speeds of MapReduceTask executions.
As
Combiners only see a part of the intermediate values, they cannot be used in all scenarios, however when used they can reduce network traffic and memory consumption in the intermediate cache significantly.
The
Collator coordinates results from Reducers that have been executed on JBoss Data Grid, and assembles a final result that is delivered to the initiator of the MapReduceTask. The Collator is applied to the final map key/value result of MapReduceTask.
Example 14.3. Assembling the Result
public interface Collator<KOut, VOut, R> {
/**
* Collates all reduced results and returns R to invoker of distributed task.
*
* @return final result of distributed task computation
*/
R collate(Map<KOut, VOut> reducedResults);14.1.1. MapReduceTask
In Red Hat JBoss Data Grid,
MapReduceTask is a distributed task, which unifies the Mapper, Combiner, Reducer, and Collator components into a cohesive computation, which can be parallelized and executed across a large-scale cluster.
These components can be specified with a fluent API. However,as most of them are serialized and executed on other nodes, using inner classes is not recommended.
Example 14.4. Specifying MapReduceTask Components
new MapReduceTask(cache)
.mappedWith(new MyMapper())
.combinedWith(new MyCombiner())
.reducedWith(new MyReducer())
.execute(new MyCollator());MapReduceTask requires a cache containing data that will be used as input for the task. The JBoss Data Grid execution environment will instantiate and migrate instances of provided Mappers and Reducers seamlessly across the nodes.
By default, all available key/value pairs of a specified cache will be used as input data for the task. This can be modified by using the
onKeys method as an input key filter.
There are two
MapReduceTask constructor parameters that determine how the intermediate values are processed:
distributedReducePhase- When set tofalse, the default setting, the reducers are only executed on the master node. If set totrue, the reducers are executed on every node in the cluster.useIntermediateSharedCache- Only important ifdistributedReducePhaseis set totrue. Iftrue, which is the default setting, this task will share intermediate value cache with other executing MapReduceTasks on the grid. If set tofalse, this task will use its own dedicated cache for intermediate values.
Note
The default timeout for
MapReduceTask is 0 (zero). That is, the task will wait indefinitely for its completion by default.
14.1.2. Specify the Target Cache
Red Hat JBoss Data Grid's MapReduce implementation allows users to specify a target cache to store the results of an executed task. The results are available after the execute method (which is synchronous) is complete.
This variant of the execute method prevents the master JVM node from exceeding its allows maximum heap size. This is especially relevant if objects that are the results of the reduce phase have a large memory footprint or if multiple MapReduceTasks are concurrently executing on the master task node.
Use the following method of MapReduceTask to specify a Cache object to store the results:
public void execute(Cache<KOut, VOut> resultsCache) throws CacheException
Use the following method of MapReduceTask to specify a name for the target cache:
public void execute(String resultsCache) throws CacheException
14.1.3. Mapper and CDI
The
Mapper is invoked with appropriate input key/value pairs on an executing node, however Red Hat JBoss Data Grid also provides a CDI injection for an input cache. The CDI injection can be used where additional data from the input cache is required in order to complete map transformation.
When the
Mapper is executed on a JBoss Data Grid executing node, the JBoss Data Grid CDI module provides an appropriate cache reference, which is injected to the executing Mapper. To use the JBoss Data Grid CDI module with Mapper:
- Declare a cache field in
Mapper. - Annotate the cache field
Mapperwith@org.infinispan.cdi.Input. - Annotate with mandatory
@Inject annotation.
Example 14.5. Using a CDI Injection
public class WordCountCacheInjecterMapper implements Mapper<String, String, String, Integer> {
@Inject
@Input
private Cache<String, String> cache;
@Override
public void map(String key, String value, Collector<String, Integer> collector) {
//use injected cache if needed
StringTokenizer tokens = new StringTokenizer(value);
while (tokens.hasMoreElements()) {
for(String token : value.split("\\w")) {
collector.emit(token, 1);
}
}
}
}14.2. MapReduceTask Distributed Execution
MapReduceTask is a distributed task that allows a large-scale computation to be transparently parallelized across Red Hat JBoss Data Grid cluster nodes. MapReduceTask can be instantiated with a reference to a cache containing data that is used as input for this task. JBoss Data Grid's execution environment can migrate and execute instances of provided
Mapper and Reducer seamlessly across JBoss Data Grid nodes.
MapReduceTask distributed execution distributes the reduce phase execution. Previously, the reduce phase was performed on a single master task node. This limitation has been removed, and the reduce phase execution can now be distributed across the cluster also. The distribution of reduce phase is achieved by relying on consistent hashing.
It is still possible to use MapReduceTask with the reduce phase performed on a single node, and this is recommended for smaller input tasks.
Distributed Execution of the MapReduceTask occurs in three phases:
- Mapping phase.
- Outgoing Key and Outgoing Value Migration.
- Reduce phase.
- Map Phase
- MapReduceTask hashes task input keys and groups them by the execution node that they are hashed to. After key node mapping, MapReduceTask sends a map function and inputs keys to each node. The map function is invoked using given keys and locally loaded corresponding values.Results are collected with a Red Hat JBoss Data Grid supplied Collector, and the combine phase is initiated. A Combiner, if specified, takes KOut keys and immediately invokes the reduce phase on keys. The result of mapping phase executed on each node is KOut/VOut map. There is one resulting map per execution node per launched MapReduceTask.
Figure 14.1. Map Phase
- Intermediate KOut/VOut migration phase
- In order to proceed with reduce phase, all intermediate keys and values must be grouped by intermediate KOut keys. As map phases around the cluster can produce identical intermediate keys, all identical intermediate keys and their values must be grouped before reduce is executed on any particular intermediate key.At the end of the combine phase, each intermediate KOut key is hashed and migrated with its VOut values to the JBoss Data Grid node where keys KOut are hashed to. This is achieved using a temporary distributed cache and underlying consistent hashing mechanism.
Figure 14.2. Kout/VOut Migration
Once Map and Combine phase have finished execution, a list of KOut keys is returned to a master node and it is initiating MapReduceTask. VOut values are not returned as they are not required at the master task node. MapReduceTask is ready to start with reduce phase. - Reduce Phase
- To complete reduce phase, MapReduceTask groups KOut keys by execution node N they are hashed to. For each node and its grouped input KOut keys, MapReduceTask sends a reduce command to a node where KOut keys are hashed. Once the reduce command is executed on the target execution node, it locates the temporary cache belonging to MapReduce task. For each KOut key, the reduce command obtains a list of VOut values, wraps it with an Iterator, and invokes reduce on it.
Figure 14.3. Reduce Phase
The result of each reduce is a map where each key is KOut and value is VOut. Each JBoss Data Grid execution node returns one map with KOut/VOut result values. As all initiated reduce commands return to a calling node, MapReduceTask combines all resulting maps into a map and returns the map as a result of MapReduceTask.Distributed reduce phase is enabled by using a MapReduceTask constructor specifying the cache to use as input data for the task and boolean parameterdistributeReducePhaseset totrue. For more information, see the Map/Reduce section of the Red Hat JBoss Data Grid API Documentation.
14.3. Map Reduce Example
The following example uses a word count application to demonstrate MapReduce and its distributed task abilities.
This example assumes we have a mapping of the key sentence stored on JBoss Data Grid nodes.
- Key is a String.
- Each sentence is a String.
All words that appear in all sentences must be counted.
Example 14.6. Implementing the Distributed Task
public class WordCountExample {
/**
* In this example replace c1 and c2 with
* real Cache references
*
* @param args
*/
public static void main(String[] args) {
Cache c1 = null;
Cache c2 = null;
c1.put("1", "Hello world here I am");
c2.put("2", "Infinispan rules the world");
c1.put("3", "JUDCon is in Boston");
c2.put("4", "JBoss World is in Boston as well");
c1.put("12","WildFly");
c2.put("15", "Hello world");
c1.put("14", "Infinispan community");
c2.put("15", "Hello world");
c1.put("111", "Infinispan open source");
c2.put("112", "Boston is close to Toronto");
c1.put("113", "Toronto is a capital of Ontario");
c2.put("114", "JUDCon is cool");
c1.put("211", "JBoss World is awesome");
c2.put("212", "JBoss rules");
c1.put("213", "JBoss division of RedHat ");
c2.put("214", "RedHat community");
MapReduceTask<String, String, String, Integer> t =
new MapReduceTask<String, String, String, Integer>(c1);
t.mappedWith(new WordCountMapper())
.reducedWith(new WordCountReducer());
Map<String, Integer> wordCountMap = t.execute();
}
static class WordCountMapper implements Mapper<String,String,String,Integer> {
/** The serialVersionUID */
private static final long serialVersionUID = -5943370243108735560L;
@Override
public void map(String key, String value, Collector<String, Integer> collector) {
StringTokenizer tokens = new StringTokenizer(value);
for(String token : value.split("\\w")) {
collector.emit(token, 1);
}
}
}
static class WordCountReducer implements Reducer<String, Integer> {
/** The serialVersionUID */
private static final long serialVersionUID = 1901016598354633256L;
@Override
public Integer reduce(String key, Iterator<Integer> iter) {
int sum = 0;
while (iter.hasNext()) {
Integer i = (Integer) iter.next();
sum += i;
}
return sum;
}
}
}
In this second example, a
Collator is defined, which will transform the result of MapReduceTask Map<KOut,VOut> into a String that is returned to a task invoker. The Collator is a transformation function applied to a final result of MapReduceTask.
Example 14.7. Defining the Collator
MapReduceTask<String, String, String, Integer> t = new MapReduceTask<String, String, String, Integer>(cache);
t.mappedWith(new WordCountMapper()).reducedWith(new WordCountReducer());
String mostFrequentWord = t.execute(
new Collator<String,Integer,String>() {
@Override
public String collate(Map<String, Integer> reducedResults) {
String mostFrequent = "";
int maxCount = 0;
for (Entry<String, Integer> e : reducedResults.entrySet()) {
Integer count = e.getValue();
if(count > maxCount) {
maxCount = count;
mostFrequent = e.getKey();
}
}
return mostFrequent;
}
});
System.out.println("The most frequent word is " + mostFrequentWord);Chapter 15. Distributed Execution
Red Hat JBoss Data Grid provides distributed execution through a standard JDK
ExecutorService interface. Tasks submitted for execution are executed on an entire cluster of JBoss Data Grid nodes, rather than being executed in a local JVM.
JBoss Data Grid's distributed task executors can use data from JBoss Data Grid cache nodes as input for execution tasks. As a result, there is no need to configure the cache store for intermediate or final results. As input data in JBoss Data Grid is already load balanced, tasks are also automatically balanced, therefore there is no need to explicitly assign tasks to specific nodes.
In JBoss Data Grid's distributed execution framework:
- Each
DistributedExecutorServiceis bound to a single cache. Tasks submitted have access to key/value pairs from that particular cache if the task submitted is an instance ofDistributedCallable. - Every
Callable,Runnable, and/orDistributedCallablesubmitted must be eitherSerializableorExternalizable, in order to prevent task migration to other nodes each time one of these tasks is performed. The value returned from aCallablemust also beSerializableorExternalizable.
15.1. DistributedCallable API
The
DistributedCallable interface is a subtype of the existing Callable from java.util.concurrent.package, and can be executed in a remote JVM and receive input from Red Hat JBoss Data Grid. The DistributedCallable interface is used to facilitate tasks that require access to JBoss Data Grid cache data.
When using the
DistributedCallable API to execute a task, the task's main algorithm remains unchanged, however the input source is changed.
Users who have already implemented
Callable interface to describe task units must extend DistributedCallable and use keys from JBoss Data Grid execution environment as input for the task.
Example 15.1. Using the DistributedCallable API
public interface DistributedCallable<K, V, T> extends Callable<T> {
/**
* Invoked by execution environment after DistributedCallable
* has been migrated for execution to a specific Infinispan node.
*
* @param cache
* cache whose keys are used as input data for this
* DistributedCallable task
* @param inputKeys
* keys used as input for this DistributedCallable task
*/
public void setEnvironment(Cache<K, V> cache, Set<K> inputKeys);
}15.2. Callable and CDI
Where
DistributedCallable cannot be implemented or is not appropriate, and a reference to input cache used in DistributedExecutorService is still required, there is an option to inject the input cache by CDI mechanism.
When the
Callable task arrives at a Red Hat JBoss Data Grid executing node, JBoss Data Grid's CDI mechanism provides an appropriate cache reference, and injects it to the executing Callable.
To use the JBoss Data Grid CDI with
Callable:
- Declare a
Cachefield inCallableand annotate it withorg.infinispan.cdi.Input - Include the mandatory
@Injectannotation.
Example 15.2. Using Callable and the CDI
public class CallableWithInjectedCache implements Callable<Integer>, Serializable {
@Inject
@Input
private Cache<String, String> cache;
@Override
public Integer call() throws Exception {
//use injected cache reference
return 1;
}
}15.3. Distributed Task Failover
Red Hat JBoss Data Grid's distributed execution framework supports task failover in the following cases:
- Failover due to a node failure where a task is executing.
- Failover due to a task failure; for example, if a
Callabletask throws an exception.
The failover policy is disabled by default, and
Runnable, Callable, and DistributedCallable tasks fail without invoking any failover mechanism.
JBoss Data Grid provides a random node failover policy, which will attempt to execute a part of a
Distributed task on another random node if one is available.
A random failover execution policy can be specified using the following as an example:
Example 15.3. Random Failover Execution Policy
DistributedExecutorService des = new DefaultExecutorService(cache); DistributedTaskBuilder<Boolean> taskBuilder = des.createDistributedTaskBuilder(new SomeCallable()); taskBuilder.failoverPolicy(DefaultExecutorService.RANDOM_NODE_FAILOVER); DistributedTask<Boolean> distributedTask = taskBuilder.build(); Future<Boolean> future = des.submit(distributedTask); Boolean r = future.get();
The
DistributedTaskFailoverPolicy interface can also be implemented to provide failover management.
Example 15.4. Distributed Task Failover Policy Interface
/**
* DistributedTaskFailoverPolicy allows pluggable fail over target selection for a failed remotely
* executed distributed task.
*
*/
public interface DistributedTaskFailoverPolicy {
/**
* As parts of distributively executed task can fail due to the task itself throwing an exception
* or it can be an Infinispan system caused failure (e.g node failed or left cluster during task
* execution etc).
*
* @param failoverContext
* the FailoverContext of the failed execution
* @return result the Address of the Infinispan node selected for fail over execution
*/
Address failover(FailoverContext context);
/**
* Maximum number of fail over attempts permitted by this DistributedTaskFailoverPolicy
*
* @return max number of fail over attempts
*/
int maxFailoverAttempts();
}15.4. Distributed Task Execution Policy
The
DistributedTaskExecutionPolicy allows tasks to specify a custom execution policy across the Red Hat JBoss Data Grid cluster, by scoping execution of tasks to a subset of nodes.
For example,
DistributedTaskExecutionPolicy can be used to manage task execution in the following cases:
- where a task is to be exclusively executed on a local network site instead of a backup remote network center.
- where only a dedicated subset of a certain JBoss Data Grid rack nodes are required for specific task execution.
Example 15.5. Using Rack Nodes to Execute a Specific Task
DistributedExecutorService des = new DefaultExecutorService(cache); DistributedTaskBuilder<Boolean> taskBuilder = des.createDistributedTaskBuilder(new SomeCallable()); taskBuilder.executionPolicy(DistributedTaskExecutionPolicy.SAME_RACK); DistributedTask<Boolean> distributedTask = taskBuilder.build(); Future<Boolean> future = des.submit(distributedTask); Boolean r = future.get();
15.5. Distributed Execution Example
In this example, parallel distributed execution is used to approximate the value of Pi (π)
- As shown below, the area of a square is:Area of a Square (S) = 4r 2
- The following is an equation for the area of a circle:Area of a Circle (C) = π x r 2
- Isolate r 2 from the first equation:r 2 = S/4
- Inject this value of r 2 into the second equation to find a value for Pi:C = Sπ/4
- Isolating π in the equation results in:C = Sπ/44C = Sπ4C/S = π
Figure 15.1. Distributed Execution Example
If we now throw a large number of darts into the square, then draw a circle inside the square, and discard all dart throws that landed outside the circle, we can approximate the C/S value.
The value of π is previously worked out to 4C/S. We can use this to derive the approximate value of π. By maximizing the amount of darts thrown, we can derive an improved approximation of π.
In the following example, we throw 10 million darts by parallelizing the dart tossing across the cluster:
Example 15.6. Distributed Execution Example
public class PiAppx {
public static void main (String [] arg){
List<Cache> caches = ...;
Cache cache = ...;
int numPoints = 10000000;
int numServers = caches.size();
int numberPerWorker = numPoints / numServers;
DistributedExecutorService des = new DefaultExecutorService(cache);
long start = System.currentTimeMillis();
CircleTest ct = new CircleTest(numberPerWorker);
List<Future<Integer>> results = des.submitEverywhere(ct);
int countCircle = 0;
for (Future<Integer> f : results) {
countCircle += f.get();
}
double appxPi = 4.0 * countCircle / numPoints;
System.out.println("Distributed PI appx is " + appxPi +
" completed in " + (System.currentTimeMillis() - start) + " ms");
}
private static class CircleTest implements Callable<Integer>, Serializable {
/** The serialVersionUID */
private static final long serialVersionUID = 3496135215525904755L;
private final int loopCount;
public CircleTest(int loopCount) {
this.loopCount = loopCount;
}
@Override
public Integer call() throws Exception {
int insideCircleCount = 0;
for (int i = 0; i < loopCount; i++) {
double x = Math.random();
double y = Math.random();
if (insideCircle(x, y))
insideCircleCount++;
}
return insideCircleCount;
}
private boolean insideCircle(double x, double y) {
return (Math.pow(x - 0.5, 2) + Math.pow(y - 0.5, 2))
<= Math.pow(0.5, 2);
}
}
}Chapter 16. Data Interoperability
16.1. Interoperability Between Library and Remote Client-Server Endpoints
Red Hat JBoss Data Grid offers multiple ways to interact with data, for example:
- store and retrieve data in a local (embedded) way
- store and retrieve data remotely using various endpoints
In previous versions of JBoss Data Grid, selecting one of these methods ensured that if one method was used to store data, the same method was required to retrieve it. For example, storing data in embedded mode required retrieval via embedded mode instead of a different method, for example using a REST endpoint.
JBoss Data Grid now offers a compatibility mode to allow users to access data with any interface regardless of the method used to store the data. In compatibility mode, the data format is automatically converted for each endpoint, which allows information to be stored and retrieved using different interfaces.
JBoss Data Grid's compatibility mode makes the following assumption about data: the most common use for compatibility mode is to store Java objects. As a result, when enabled, compatibility mode unmarshalls or deserializes data when storing it. This results in increased efficiency when using Java objects with an embedded cache.
Compatibility mode comes at a higher performance cost than non-compatibility mode. As a result, this feature is disabled by default in JBoss Data Grid.
16.2. Using Compatibility Mode
Red Hat JBoss Data Grid's compatibility mode requires the following to work as expected:
- all endpoints configurations specify the same cache manager
- all endpoints can interact with the same target cache
Using JBoss Data Grid's Remote Client-Server distribution ensures that these requirements are configured by default.
16.3. Protocol Interoperability
Red Hat JBoss Data Grid protocol interoperability allows data in the form of raw bytes to be read/write accessed by different protocols, such as REST, Memcached, library, and Hot Rod, that are written in various programming languages, such as C++ or Java.
By default, each protocol stores data in the most efficient format for that protocol, ensuring transformations are not required when retrieving entries. When this data is required to be accessed from multiple protocols, compatibility mode must be enabled on caches that are being shared.
Enable Compatibility Mode declaratively in Client-Server mode
The compatibility element's enabled parameter is set to true or false to determine whether compatibility mode is in use.
Example 16.1. Compatibility Mode Enabled
<cache-container name="local" default-cache="default" statistics="true">
<local-cache name="default" start="EAGER" statistics="true">
<compatibility enabled="true"/>
</local-cache>
</cache-container>Enable Compatibility Mode programmatically in Library mode
Use a configurationBuilder with the compatibility mode enabled as follows:
ConfigurationBuilder builder = ... builder.compatibility().enable();
Enable Compatibility Mode declaratively in Library mode
The compatibility element's enabled parameter is set to true or false to determine whether compatibility mode is in use.
<namedCache name="compatcache"> <compatibility enabled="true"/> </namedCache>
16.3.1. Use Cases and Requirements
The following table outlines typical use cases for data interoperability in Red Hat JBoss Data Grid.
Table 16.1. Compatibility Mode Use Cases
| Use Case | Client A (Reader or Writer) | Client B (Write/Read Counterpart of Client A) |
|---|---|---|
| 1 | Memcached | Hot Rod Java |
| 2 | REST | Hot Rod Java |
| 3 | Memcached | REST |
| 4 | Hot Rod Java | Hot Rod C++ |
| 5 | Embedded | Hot Rod Java |
| 6 | REST | Hot Rod C++ |
| 7 | Memcached | Hot Rod C++ |
In the provided use cases, marshalling is entirely up to the user. JBoss Data Grid stores a byte[], while the user marshalls or unmarshalls this into meaningful data.
For example, in Use Case 1, interoperability is between a Memcached client (A), and a Hot Rod Java client (B). If Client A wishes to serialize an application-specific Object, such as a
Person instance, it would use a String as a key.
The following steps apply to all use cases:
Client A Side
- A uses a third-party marshaller, such as Protobuf or Avro, to serialize the
Personvalue into a byte[]. A UTF-8 encoded string must be used as the key (according to Memcached protocol requirements). - A writes a key-value pair to the server (key as UTF-8 string, the value as byte arrays).
Client B Side
- B must read a
Personfor a specific key (String). - B serializes the same UTF-8 key into the corresponding byte[].
- B invokes
get(byte[]) - B obtains a byte[] representing the serialized object.
- B uses the same marshaller as A to unmarshall the byte[] into the corresponding
Personobject.
Note
- In Use Case 4, the Protostream Marshaller, which is included with the Hot Rod Java client, is recommended. For the Hot Rod C++ client, the Protobuf Marshaller from Google (https://developers.google.com/protocol-buffers/docs/overview) is recommended.
- In Use Case 5, the default Hot Rod marshaller can be used.
16.3.2. Protocol Interoperability Over REST
When data is stored via the REST interface the values are interpreted by embedded, Hot Rod or Memcached clients as a sequence of bytes. Meaning is given to this byte-sequence using the MIME type specified via the "Content-Type" HTTP header, but the content type information is only available to REST clients. No specific interoperability configuration is required for this to occur.
When retrieving data via REST, primitive types stored are read in their primitive format. If a UTF-8 String has been stored via Hot Rod, Embedded, or Memcached, it will be retrieved as String from REST. If custom objects have been serialized and stored via the embedded or remote cache, these can be retrieved as
application/x-java-serialized-object, application/xml, or application/json. Any other byte arrays are treated as application/octet-stream.
Appendix A. Revision History
| Revision History | ||||||
|---|---|---|---|---|---|---|
| Revision 6.3.0-20 | Mon Jan 12 2015 | |||||
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| Revision 6.3.0-19 | Mon Jan 05 2015 | |||||
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| Revision 6.3.0-18 | Fri Dec 05 2014 | |||||
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| Revision 6.3.0-17 | Wed Dec 03 2014 | |||||
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| Revision 6.3.0-16 | Mon Nov 17 2014 | |||||
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| Revision 6.3.0-15 | Fri Nov 07 2014 | |||||
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| Revision 6.3.0-14 | Wed Oct 22 2014 | |||||
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| Revision 6.3.0-13 | Wed Oct 08 2014 | |||||
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| Revision 6.3.0-12 | Wed Sep 10 2014 | |||||
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| Revision 6.3.0-11 | Tue Sep 02 2014 | |||||
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| Revision 6.3.0-10 | Tue Aug 26 2014 | |||||
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| Revision 6.3.0-9 | Mon Aug 18 2014 | |||||
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| Revision 6.3.0-2 | Mon May 26 2014 | |||||
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| Revision 6.3.0-1 | Thu May 22 2014 | |||||
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| Revision 6.3.0-0 | Wed Apr 09 2014 | |||||
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