[jboss-user] [EJB 3.0] - Read lot of objects with OPTIMISTIC Locking scheme

[apdo]

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


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