EclipseLink Cache not getting cached - caching

Question

#NamedQuery(
name=DBConstants.SERVICE_BY_ID, query="select s from Service s where s.id= :id",
hints={
#QueryHint(name = QueryHints.QUERY_RESULTS_CACHE, value = HintValues.TRUE),
#QueryHint(name = QueryHints.QUERY_RESULTS_CACHE_SIZE, value = "500")
})
I am using different entity manager on every query request.
Query query = em.createNamedQuery(DBConstants.SERVICE_BY_ID);
query.setParameter("id", id);
result = (Service) query.getSingleResult();
This is always returning data from database but not from Cache.
How I tested -> I changed some column value in database and when I performed the query, the modified value is coming. Ideally it should return stale data since the cache is not refreshed OR invalidated.
Revision 2:
If we are trying to cache named queries, then using multitenant aware persistence classes will cause problem. How? Here is the way I think it works:
#Cache(
type=CacheType.SOFT,
size=6000,
expiry=600000
)
#Multitenant
#TenantDiscriminatorColumn(...)
#NamedQueries({
#NamedQuery(
name=DBConstants.ALL_SERVICES, query="select s from Service s",
hints={
#QueryHint(name = QueryHints.QUERY_RESULTS_CACHE, value = HintValues.TRUE),
#QueryHint(name = QueryHints.QUERY_RESULTS_CACHE_SIZE, value = "10")
})
})
})
#IdClass(ServicePK.class)
public class Service implements Serializable { ... }
Creation of EMF:
String tenantID = getTenantID();
properties.put(DBConstants.TENANT_ID_CONTEXT_PROPERTY, tenantID);
properties.put(DBConstants.LINK_SESSION_NAME, "session-" + tenantID);
if(emf == null)
emf = Persistence.createEntityManagerFactory("<PERSISTENCE_UNIT_NAME>", properties);
Creation of EM:
em = emf.createEntityManager();
In this case, our named query "ALL_SERVICES" is to search for all services and we want named query cache to cache based on that query. But when we execute this query, EM appends the tenantId to the query i.e.
select s from Service s where s.tenantID = <VALUE>
This is cached in the isolated cache of the L1 cache and is available till you use the same EM instance.
When you create a new EM instance, it checks if the entry is present in the L2 cache before trying to invoke query on DB. L2 caches only based on the query we mentioned but not with the tenantId appended. This causes cache hit miss and the call always goes to backend.
Now... How do I solve this problem? I can remove multitenant annotations and add tenantId myself in the query. I tested it and it works absolutely fine.
But removing multitenant annotation causes lot of condition checks to be done manually especially when we have dependencies on other persistence classes.
I need a better solution. Can anyone help???