0 Replies Latest reply on Dec 6, 2008 10:29 PM by apdo

    Read lot of objects with OPTIMISTIC Locking scheme

    apdo Newbie

      I know that EJB are not used to retrieve very long list of objects.

      However I have performed a simple test and I would like to confirm with you that result are obtained from correct configuration.

      Objects:
      Account entity with parameters id, username, realname, password
      Role entity with parameters id, name, description

      There is a relation m to n between Account and Role


      Configuration:

      Persistence.xml
      <persistence>
      <persistence-unit name="securityEJB3">
      <jta-data-source>java:/securityEJB3DS</jta-data-source>
      <properties>
      <property name="hibernate.hbm2ddl.auto" value="update"/>
      <property name="hibernate.dialect" value="org.hibernate.dialect.SQLServerDialect"/>
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.cache.use_query_cache" value="true"/>
      <property name="hibernate.cache.provider_class" value="org.jboss.ejb3.entity.TreeCacheProviderHook" />
      <property name="hibernate.treecache.mbean.object_name" value="jboss.cache:service=EJB3EntityTreeCache" />
      </properties>
      </persistence-unit>
      </persistence>
      


      To enable caching on the default configuration, I follow the french instruction provided in at the following location:
      http://wiki.objetdirect.com/wiki/index.php?title=Cache_2nd_niveau_Hibernate

      Ejb3-entity-cache-service.xml
      <attribute name="NodeLockingScheme">OPTIMISTIC</attribute>
      <attribute name="IsolationLevel">REPEATABLE_READ</attribute>
      <attribute name="CacheMode">LOCAL</attribute>
      
      Everything else is left to the default values
      



      Test Results:

      100000 Account and 100 role have been inserted.

      For test 2 and 3:
      Retrieving all Account using a entityManager.createQuery("from Account a") it takes


      Test 1:
      Simple select from SQL server management studio.
      It take 1 second to display the whole list of Account

      Test 2:
      With pessimistic locking:
      PESSIMISTIC

      About 10 second for the first call and then about 4 seconds using the cache


      Test 3:
      Thisi test has been executed with optimistic locking enabled.
      OPTIMISTIC


      Timeout after 5 minutes of execution

      I have read that using OPTIMISTIC locking required additional overhead due to the copy of the cache entries.
      However, I would like to know if the behaviour I got is normal or is there something I miss configured with the OPTIMISTIC locking.

      Thanks to give me you comments on my tests and suggestion if configuration need to be changes.

      An Phong Do