EHCache doesn't seem to work

Question

Hello guys,

I've set up ehcache on our Java application, which uses Spring and Hibernate. However, when I run Junit tests and print the stats, it seems there is nothing in cache:

OUTPUT OF CACHE MANAGER STATS ON EVERY CACHE:

COM.****.SERVICES.CLARITY.DOMAIN.ACTIONITEM.BYRESOURCEUNIQUENAME: getCacheHits: 0 getCacheMisses: 0 getObjectCount: 0

COM.****.SERVICES.CLARITY.DOMAIN.ACTIONITEM: getCacheHits: 0 getCacheMisses: 0 getObjectCount: 0

COM.****.SERVICES.CLARITY.DOMAIN.RESOURCE: getCacheHits: 0 getCacheMisses: 0 getObjectCount: 0

CONTENT OF THE MAPPING FILE (ONLY PARTS, TOO BIG TO PASTE ALL):

<class name="ActionItem" table="CAL_ACTION_ITEMS" mutable="false" lazy="false" >
<cache region="com.****.services.clarity.domain.ActionItem" usage="read-only" include="all" />

[...]

<query name="byResourceUniqueName" cacheable="true" cache-region="com.****.services.clarity.domain.ActionItem.byResourceUniqueName" read-only="true">
 FROM ActionItem WHERE id IN (
  SELECT DISTINCT actionItemId FROM ActionItemAssignee as aia WHERE assigneeId IN (
   SELECT userId FROM Resource WHERE uniqueName = :uniqueName
  )
 )
 ORDER BY dueDate
</query>

CONTENT OF EHCACHE.XML:

<cache
 name="com.****.services.clarity.domain.ActionItem"
 maxElementsInMemory="2000" eternal="false" timeToIdleSeconds="0"
 timeToLiveSeconds="600" overflowToDisk="false" />

<cache
 name="com.****.services.clarity.domain.ActionItem.byResourceUniqueName"
 maxElementsInMemory="2000" eternal="false" timeToIdleSeconds="0"
 timeToLiveSeconds="60" overflowToDisk="false" />

<defaultCache maxElementsInMemory="200" eternal="false"
 timeToIdleSeconds="120" timeToLiveSeconds="120" overflowToDisk="true"
 memoryStoreEvictionPolicy="LRU" />

HIBERNATE CONFIG:

 <property name="hibernateProperties">
  <value>
   hibernate.format_sql=true
   hibernate.dialect=org.hibernate.dialect.OracleDialect
   hibernate.cache.provider_class=net.sf.ehcache.hibernate.EhCacheProvider
   hibernate.cache.use_query_cache=true
   hibernate.show_sql=true
  </value>
 </property>
</bean>

Any ideas on how to populate the cache ? Thanks.

Answer 1

First of all, are you sure cache usage for ActionItems should be read-only? How are the those items populated initially? And, even if that is correct for your business model, consider changing it to nonstrict-read-write, to see if it changes anything in your test.

Then, have you tried executing byResourceUniqueName query with caching enabled:

Query q = getSession().getNamedQuery("byResourceUniqueName");
q.setCacheable(true);
List result = q.list();

Even though cacheable parameter should influence only caching of the result set of the query, again, see if it changes anything.

Answer 2

Normally the items get populated to the cache by Hibernate automatically.

One thing I noticed in your configuration is that you didn't enable the statistics. Add the property

hibernate.generate_statistics=true

to your session factory's configuration and see, if numbers occur in your output.

Answer 3

Try using the net.sf.ehcache.hibernate.SingletonEhCacheProvider instead of the net.sf.ehcache.hibernate.EhCacheProvider