Chapter 19. Red Hat JBoss Data Grid as Lucene Directory

Red Hat JBoss Data Grid can be used as a shared, in-memory index (Infinispan Directory) for Hibernate Search queries on a relational database. By default, Hibernate Search uses a local filesystem to store the Lucene indexes but optionally it can be configured to use JBoss Data Grid as a storage to achieve real-time replication across multiple server nodes.
In the Infinispan Directory, the index is stored in memory and shared across multiple nodes. The Infinispan Directory acts as a single directory distributed across all participating nodes. An index update on one node updates the index on all the nodes. Index can be searched immediately after the node update across the cluster. The default Hibernate Search configuration replicates the data defining the index across all the nodes.
Data distribution for large indexes may be enabled to consume less memory; however, this will come at a cost of locality resulting in query operations less efficient. The indexed data can also be offloaded to a CacheStore configured on each node or configure a single centralized CacheStore shared by each node.


While enabling distribution rather than replication might save memory, the queries will be slower. Enabling a CacheStore might save even more memory, but at cost of additional performance if used for passivation.

19.1. Configuration

The directory provider is enabled by specifying it per index. If the default index is specified then all indexes will use the directory provider unless specified:[default|<indexname>].directory_provider = infinispan
This gives a cluster-replicated index, but the default configuration does not enable any form of permanent persistence for the index. To enable such a feature provide an Infinispan configuration file.
Hibernate Search requires a CacheManager to use Infinispan. It can look up and reuse an existing CacheManager, via JNDI, or start and manage a new one. When looking up an existing CacheManager this will be provided from the Infinispan subsystem where it was originally registered; for instance, if this was registered via JBoss EAP, then JBoss EAP's Infinispan subsystem will provide the CacheManager.


When using JNDI to register a CacheManager, it must be done using Red Hat JBoss Data Grid configuration files only.
To use an existing CacheManager via JNDI (optional parameter): = [jndiname]
To start a new CacheManager from a configuration file (optional parameter): = [infinispan configuration filename]
If both the parameters are defined, JNDI will have priority. If none of these are defined, Hibernate Search will use the default Infinispan configuration which does not store the index in a persistent cache store.