Batch Index using Hibernate Search and Seam
We need to index a large number of records using Hibernate Search;
Following the documentations and examples from SEAM, we have implemented the followings. This is to eliminate Out Of Memory Exception and Timeout Exception when indexing a large number of records.
The method works fine (well, haven?t tested it with a large number yet) when it is called from a stateful seam component (as the backing bean for use actions).
However, since this would be a long running process we need to add the @Asynchronous. Adding this annotation stops the method after the EntityManager call and log.info("EntityManager initilized."); is never called !
The persistence.xml has been modified for the specified batchSize as per documentation.
Your help and feedback is highly appreciated;
Environment:
JBoss-4.2.1
SEAM-2.0.CR1
RichFaces-3.1.2
@Name("indexManager")
public class IndexManagerBean {
@Logger
static Log log;
public int batchSize = 50;
//@Asynchronous
public void buildIndex(Class entityClass) {
log.info("asynchronously rebuilding Lucene index for entity: " + entityClass);
EntityManager em = (EntityManager) Component.getInstance("entityManager");
log.info("EntityManager initilized.");
FullTextSession fullTextSession = (FullTextSession)em.getDelegate();
fullTextSession.setFlushMode(FlushMode.MANUAL);
fullTextSession.setCacheMode(CacheMode.IGNORE);
org.hibernate.Transaction transaction = fullTextSession.beginTransaction();
//Scrollable results will avoid loading too many objects in memory
ScrollableResults results = fullTextSession.createCriteria( entityClass ).scroll( ScrollMode.FORWARD_ONLY);
int index = 0;
while( results.next() ) {
index++;
fullTextSession.index( results.get(0) ); //index each element
if (index % batchSize == 0) fullTextSession.clear(); //clear every batchSize since the queue is processed
}
transaction.commit();
try {
if (results != null) results.close();
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
The entityManager is configured in the components.xml as:
<persistence:filter name="accessCompanyFilter">
<persistence:name>accessCompanyFilter</persistence:name>
<persistence:parameters>
<key>currentAccessCompany</key>
<value>#{currentAccessCompany}</value>
</persistence:parameters>
</persistence:filter>
<persistence:managed-persistence-context name="entityManager"
auto-create="true"
entity-manager-factory="#{TestEntityManagerFactory}"
persistence-unit-jndi-name="java:/ TestEntityManagerFactory">
<persistence:filters><value>#{accessCompanyFilter}</value></persistence:filters>
</persistence:managed-persistence-context>
<persistence:managed-persistence-context name="gloabalEntityManager"
auto-create="true"
entity-manager-factory="#{TestEntityManagerFactory}"
persistence-unit-jndi-name="java:/TestEntityManagerFactory">
</persistence:managed-persistence-context>
