EntityManager.lock and database connections
ablevine1 Sep 4, 2007 2:07 PMWhen you use EntityManager.lock, does it hold on to the same database connection the whole time, not allowing other threads to use that connection?? I seem to be running out of connections in my connection pool, as I am getting the following exception:
INFO [WorkManager(4)-53846][2007-09-03 04:23:33,657][org.hibernate.event.def.DefaultLoadEventListener] Log4JLogger.java(99): Error performing load command org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103) at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:420) at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144) at org.hibernate.jdbc.AbstractBatcher.prepareQueryStatement(AbstractBatcher.java:139) at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1560) at org.hibernate.loader.Loader.doQuery(Loader.java:661) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224) at org.hibernate.loader.Loader.loadEntity(Loader.java:1784) at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:48) at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:42) at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:2977) at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:393) at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:374) at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:137) at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:193) at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:101) at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:878) at org.hibernate.impl.SessionImpl.get(SessionImpl.java:815) at org.hibernate.impl.SessionImpl.get(SessionImpl.java:808) at org.hibernate.ejb.AbstractEntityManagerImpl.find(AbstractEntityManagerImpl.java:174) at org.jboss.ejb3.entity.TransactionScopedEntityManager.find(TransactionScopedEntityManager.java:164) at com.squaretrade.stateful.AbstractStateEngineImpl.loadObject(AbstractStateEngineImpl.java:118) at com.squaretrade.stateful.AbstractStateEngineImpl.process(AbstractStateEngineImpl.java:31) at sun.reflect.GeneratedMethodAccessor1671.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79) at org.jboss.aspects.tx.TxInterceptor$RequiresNew.invoke(TxInterceptor.java:253) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77) at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:102) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:47) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:211) at org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:79) at $Proxy339.process(Unknown Source) at com.squaretrade.stateful.AbstractStateEngineQueueHandler.onMessage(AbstractStateEngineQueueHandler.java:38) at sun.reflect.GeneratedMethodAccessor1669.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:46) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.aspects.tx.TxPolicy.invokeInCallerTx(TxPolicy.java:126) at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:195) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.mdb.MessagingContainer.localInvoke(MessagingContainer.java:245) at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.delivery(MessageInflowLocalProxy.java:268) at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.invoke(MessageInflowLocalProxy.java:138) at $Proxy138.onMessage(Unknown Source) at org.jboss.resource.adapter.jms.inflow.JmsServerSession.onMessage(JmsServerSession.java:183) at org.jboss.mq.SpyMessageConsumer.sessionConsumerProcessMessage(SpyMessageConsumer.java:905) at org.jboss.mq.SpyMessageConsumer.addMessage(SpyMessageConsumer.java:170) at org.jboss.mq.SpySession.run(SpySession.java:323) at org.jboss.resource.adapter.jms.inflow.JmsServerSession.run(JmsServerSession.java:249) at org.jboss.resource.work.WorkWrapper.execute(WorkWrapper.java:204) at org.jboss.util.threadpool.BasicTaskWrapper.run(BasicTaskWrapper.java:275) at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(PooledExecutor.java:743) at java.lang.Thread.run(Thread.java:595) Caused by: org.jboss.util.NestedSQLException: No ManagedConnections available within configured blocking timeout ( 30000 [ms] ); - nested throwable: (javax.resource.ResourceException: No ManagedConnections available within configured blocking timeout ( 30000 [ms] )) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:94) at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:47) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:417) ... 79 more Caused by: javax.resource.ResourceException: No ManagedConnections available within configured blocking timeout ( 30000 [ms] ) at org.jboss.resource.connectionmanager.InternalManagedConnectionPool.getConnection(InternalManagedConnectionPool.java:289) at org.jboss.resource.connectionmanager.JBossManagedConnectionPool$BasePool.getConnection(JBossManagedConnectionPool.java:529) at org.jboss.resource.connectionmanager.BaseConnectionManager2.getManagedConnection(BaseConnectionManager2.java:341) at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:301) at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:396) at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:842) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:88) ... 81 more
I was wondering if this could be caused by using EntityManager.lock where the lock is held for about a second. There does not seem to be a deadlock, but the oracle connection pool seems to be running out of connections intermittently, and I'm trying to figure out the possible causes.