11.6. Hot Rod Java Client

Hot Rod is a binary, language neutral protocol. A Java client is able to interact with a server via the Hot Rod protocol using the Hot Rod Java Client API.

11.6.1. Hot Rod Java Client Download

Use the following steps to download the JBoss Data Grid Hot Rod Java Client:

Procedure 11.1. Download Hot Rod Java Client

  1. Log into the Customer Portal at https://access.redhat.com.
  2. Click the Downloads button near the top of the page.
  3. In the Product Downloads page, click Red Hat JBoss Data Grid.
  4. Select the appropriate JBoss Data Grid version from the Version: drop down menu.
  5. Locate the Red Hat JBoss Data Grid ${VERSION} Hot Rod Java Client entry and click the corresponding Download link.

11.6.2. Hot Rod Java Client Configuration

The Hot Rod Java client is configured both programmatically and externally using a configuration file or a properties file. The following example illustrate creation of a client instance using the available Java fluent API:

Example 11.1. Client Instance Creation

org.infinispan.client.hotrod.configuration.ConfigurationBuilder cb
= new org.infinispan.client.hotrod.configuration.ConfigurationBuilder();
cb.tcpNoDelay(true)
  .connectionPool()
      .numTestsPerEvictionRun(3)
      .testOnBorrow(false)
      .testOnReturn(false)
      .testWhileIdle(true)
  .addServer()
      .host("localhost")
      .port(11222);
RemoteCacheManager rmc = new RemoteCacheManager(cb.build());
Configuring the Hot Rod Java client using a properties file

To configure the Hot Rod Java client, edit the hotrod-client.properties file on the classpath.

The following example shows the possible content of the hotrod-client.properties file.

Example 11.2. Configuration

infinispan.client.hotrod.transport_factory = org.infinispan.client.hotrod.impl.transport.tcp.TcpTransportFactory

infinispan.client.hotrod.server_list = 127.0.0.1:11222

infinispan.client.hotrod.marshaller = org.infinispan.commons.marshall.jboss.GenericJBossMarshaller

infinispan.client.hotrod.async_executor_factory = org.infinispan.client.hotrod.impl.async.DefaultAsyncExecutorFactory

infinispan.client.hotrod.default_executor_factory.pool_size = 1

infinispan.client.hotrod.default_executor_factory.queue_size = 10000

infinispan.client.hotrod.hash_function_impl.1 = org.infinispan.client.hotrod.impl.consistenthash.ConsistentHashV1

infinispan.client.hotrod.tcp_no_delay = true

infinispan.client.hotrod.ping_on_startup = true

infinispan.client.hotrod.request_balancing_strategy = org.infinispan.client.hotrod.impl.transport.tcp.RoundRobinBalancingStrategy

infinispan.client.hotrod.key_size_estimate = 64

infinispan.client.hotrod.value_size_estimate = 512

infinispan.client.hotrod.force_return_values = false

infinispan.client.hotrod.tcp_keep_alive = true

## below is connection pooling config

maxActive=-1

maxTotal = -1

maxIdle = -1

whenExhaustedAction = 1

timeBetweenEvictionRunsMillis=120000

minEvictableIdleTimeMillis=300000

testWhileIdle = true

minIdle = 1

Note

The TCP KEEPALIVE configuration is enabled/disabled on the Hot Rod Java client either through a config property as seen in the example (infinispan.client.hotrod.tcp_keep_alive = true/false or programmatically through the org.infinispan.client.hotrod.ConfigurationBuilder.tcpKeepAlive() method.
Either of the following two constructors must be used in order for the properties file to be consumed by Red Hat JBoss Data Grid:
  1. new RemoteCacheManager(boolean start)
  2. new RemoteCacheManager()

11.6.3. Hot Rod Java Client Basic API

The following code shows how the client API can be used to store or retrieve information from a Hot Rod server using the Hot Rod Java client. This example assumes that a Hot Rod server has been started bound to the default location, localhost:11222.

Example 11.3. Basic API

//API entry point, by default it connects to localhost:11222
        BasicCacheContainer cacheContainer = new RemoteCacheManager();
//obtain a handle to the remote default cache
        BasicCache<String, String> cache = cacheContainer.getCache();
//now add something to the cache and ensure it is there
        cache.put("car", "ferrari");
        assert cache.get("car").equals("ferrari");
//remove the data
        cache.remove("car");
        assert !cache.containsKey("car") : "Value must have been removed!";
The RemoteCacheManager corresponds to DefaultCacheManager, and both implement BasicCacheContainer.
This API facilitates migration from local calls to remote calls via Hot Rod. This can be done by switching between DefaultCacheManager and RemoteCacheManager, which is simplified by the common BasicCacheContainer interface.
All keys can be retrieved from the remote cache using the keySet() method. If the remote cache is a distributed cache, the server will start a Map/Reduce job to retrieve all keys from clustered nodes and return all keys to the client.
Use this method with caution if there are a large number of keys.
Set keys = remoteCache.keySet();

11.6.4. Hot Rod Java Client Versioned API

To ensure data consistency, Hot Rod stores a version number that uniquely identifies each modification. Using getVersioned, clients can retrieve the value associated with the key as well as the current version.
When using the Hot Rod Java client, a RemoteCacheManager provides instances of the RemoteCache interface that accesses the named or default cache on the remote cluster. This extends the Cache interface to which it adds new methods, including the versioned API.

Example 11.4. Using Versioned Methods

// To use the versioned API, remote classes are specifically needed
RemoteCacheManager remoteCacheManager = new RemoteCacheManager();
RemoteCache<String, String> remoteCache = remoteCacheManager.getCache();
remoteCache.put("car", "ferrari");
VersionedValue valueBinary = remoteCache.getVersioned("car");
// removal only takes place only if the version has not been changed
// in between. (a new version is associated with 'car' key on each change)
assert remoteCache.removeWithVersion("car", valueBinary.getVersion());
assert !remoteCache.containsKey("car");

Example 11.5. Using Replace

remoteCache.put("car", "ferrari");
VersionedValue valueBinary = remoteCache.getVersioned("car");
assert remoteCache.replaceWithVersion("car", "lamborghini", valueBinary.getVersion());