Ehcache seems not work - jpa

Question

Now I want to use JPA second level cache by ehache. I made some configuration and it seems work. But I still can see the query sql. I'm not sure ehcache is working. Does anybody know about that? Thanks.
1.some part of persistence.xml
<property name="hibernate.cache.region.factory_class" value="org.hibernate.cache.ehcache.EhCacheRegionFactory" />
<property name="hibernate.cache.provider_configuration" value="/ehcache.xml" />
<property name="hibernate.generate_statistics" value="true" />
<property name="hibernate.cache.use_second_level_cache" value="true" />
<property name="hibernate.cache.use_query_cache" value="true" />
<property name="hibernate.show_sql" value="true" />
2.ehcache.xml
<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
<defaultCache maxElementsInMemory="1" eternal="false"
timeToIdleSeconds="1200" timeToLiveSeconds="1200" overflowToDisk="true" clearOnFlush="true">
</defaultCache>
<cache name="org.test.persistent.entity.Scenario"
maxElementsInMemory="10000"
eternal="false"
timeToIdleSeconds="1800"
timeToLiveSeconds="3600"
overflowToDisk="true">
</cache>
<cache name="org.hibernate.cache.spi.UpdateTimestampsCache"
maxElementsInMemory="10000"
timeToIdleSeconds="1800"
timeToLiveSeconds="3600"
eternal="false">
</cache>
</ehcache>
3. sql
TypedQuery<Scenario> query = em.createQuery(
"from Scenario as s where s.obsolete!=1 and s.parentId=? order by s.name, s.scenarioStatusId",
Scenario.class);
query.setParameter(1, parentId);
query.setHint("org.hibernate.cacheable", true);
List<Scenario> scenarios = null;
org.hibernate.Query hbQuery = null;
if (query instanceof org.hibernate.ejb.QueryImpl) {
hbQuery = ((org.hibernate.ejb.QueryImpl)query).getHibernateQuery();
hbQuery.setCacheable(true);
scenarios = hbQuery.list();
} else {
scenarios = query.getResultList();
}

Answer 1

Ehcache setting is having its default value maxElementsInMemory="10000". It has to be tuned according to the hits.
One way to do this is, You can increase maxElementsInMemory and check if you want to solve this by "Trial and error" method.
Other way (reliable) is that you have to publish the Mbeans and watch for the cache usage and cache misses in JConsole. According to the report you can increase 'maxElementsInMemory'. Please refer how you should do that in http://hibernate-jcons.sourceforge.net/usage.html

Answer 2

I write cache data to disk by adding "". It seems work well and I find some data in the directory. But I still not find the reason of why it still execute sql.