Error: PersistenceExceptionorg.hibernate.exception.GenericJDBCException: Cannot open connection

This problem has been causing me headaches, lately. After some heavy googling, I came across the following explanation.

The biggest problem here is that at first glance in my stacktrace it totally looked like a transaction/sqlserver problem.

Here's the stacktrace:

2011-07-23 22:23:46,805 WARN [org.hibernate.util.JDBCExceptionReporter] [ ] SQL Error: 0, SQLState: null 2011-07-23 22:23:46,805 ERROR [org.hibernate.util.JDBCExceptionReporter] [ ] Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) 2011-07-23 22:23:46,805 ERROR [nl.isaac.youw8.ejb.StorageServiceBean] [ ] Error: PersistenceExceptionorg.hibernate.exception.GenericJDBCException: Cannot open connection searching an DashboardUser Query: from DashboardUser WHERE id = :id ORDER BY ID DESC javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:99) at nl.isaac.youw8.ejb.StorageServiceBean.findSingle(StorageServiceBean.java:673) at nl.isaac.youw8.ejb.StorageServiceBean.findSingleObjectLike(StorageServiceBean.java:136) at sun.reflect.GeneratedMethodAccessor778.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at youw8.interceptors.DefaultInterceptor.intercept(DefaultInterceptor.java:140) at sun.reflect.GeneratedMethodAccessor220.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:118) 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:47) 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.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) 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.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:166) at org.jboss.ejb3.security.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:115) 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:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) 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:240) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:210) at org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:84) at $Proxy157.findSingleObjectLike(Unknown Source) at youw8.services.exposed.webservices.rest.MeasurementsResource.addActivityMeasurement(MeasurementsResource.java:486) at sun.reflect.GeneratedMethodAccessor1608.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:184) at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:67) at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:276) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:83) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:71) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1171) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1103) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1053) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1043) at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:406) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:477) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:662) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at youw8.services.exposed.oauth.provider.servlets.AuthorizationServlet.doFilter(AuthorizationServlet.java:259) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:856) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:566) at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1508) at java.lang.Thread.run(Thread.java:619) Caused by: 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:426) 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:1547) at org.hibernate.loader.Loader.doQuery(Loader.java:673) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) at org.hibernate.loader.Loader.doList(Loader.java:2220) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) at org.hibernate.loader.Loader.list(Loader.java:2099) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:378) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:338) at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:80) ... 75 more Caused by: org.jboss.util.NestedSQLException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:95) at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:47) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:423) ... 89 more Caused by: javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY > at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:319) at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:402) at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:849) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89) ... 91 more 2011-07-23 22:23:46,805 WARN [org.hibernate.util.JDBCExceptionReporter] [ ] SQL Error: 0, SQLState: null 2011-07-23 22:23:46,805 ERROR [org.hibernate.util.JDBCExceptionReporter] [ ] Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) 2011-07-23 22:23:46,805 ERROR [nl.isaac.youw8.ejb.StorageServiceBean] [ ] Error: PersistenceExceptionorg.hibernate.exception.GenericJDBCException: Cannot open connection searching an Activity Query: from Activity WHERE id = :id ORDER BY ID DESC javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:99) at nl.isaac.youw8.ejb.StorageServiceBean.findSingle(StorageServiceBean.java:673) at nl.isaac.youw8.ejb.StorageServiceBean.findSingleObjectLike(StorageServiceBean.java:136) at sun.reflect.GeneratedMethodAccessor778.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166) at youw8.interceptors.DefaultInterceptor.intercept(DefaultInterceptor.java:140) at sun.reflect.GeneratedMethodAccessor220.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:118) 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:47) 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.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95) 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.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:166) at org.jboss.ejb3.security.RoleBasedAuthorizationInterceptor.invoke(RoleBasedAuthorizationInterceptor.java:115) 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:110) at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101) at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46) 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:240) at org.jboss.ejb3.stateless.StatelessContainer.localInvoke(StatelessContainer.java:210) at org.jboss.ejb3.stateless.StatelessLocalProxy.invoke(StatelessLocalProxy.java:84) at $Proxy157.findSingleObjectLike(Unknown Source) at youw8.services.exposed.webservices.rest.MeasurementsResource.addActivityMeasurement(MeasurementsResource.java:490) at sun.reflect.GeneratedMethodAccessor1608.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:184) at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:67) at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:276) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:83) at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:133) at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:71) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1171) at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1103) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1053) at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1043) at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:406) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:477) at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:662) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at youw8.services.exposed.oauth.provider.servlets.AuthorizationServlet.doFilter(AuthorizationServlet.java:259) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:182) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:856) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:566) at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1508) at java.lang.Thread.run(Thread.java:619) Caused by: 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:426) 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:1547) at org.hibernate.loader.Loader.doQuery(Loader.java:673) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:236) at org.hibernate.loader.Loader.doList(Loader.java:2220) at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2104) at org.hibernate.loader.Loader.list(Loader.java:2099) at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:378) at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:338) at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:172) at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1121) at org.hibernate.impl.QueryImpl.list(QueryImpl.java:79) at org.hibernate.ejb.QueryImpl.getSingleResult(QueryImpl.java:80) ... 75 more Caused by: org.jboss.util.NestedSQLException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >; - nested throwable: (javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY >) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:95) at org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider.getConnection(InjectedDataSourceConnectionProvider.java:47) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:423) ... 89 more Caused by: javax.resource.ResourceException: Transaction is not active: tx=TransactionImple < ac, BasicAction: 53f73f9b:8b5:4e26e1da:501d3a status: ActionStatus.ABORT_ONLY > at org.jboss.resource.connectionmanager.TxConnectionManager.getManagedConnection(TxConnectionManager.java:319) at org.jboss.resource.connectionmanager.BaseConnectionManager2.allocateConnection(BaseConnectionManager2.java:402) at org.jboss.resource.connectionmanager.BaseConnectionManager2$ConnectionManagerProxy.allocateConnection(BaseConnectionManager2.java:849) at org.jboss.resource.adapter.jdbc.WrapperDataSource.getConnection(WrapperDataSource.java:89) ... 91 more 2011-07-23 22:23:46,805 ERROR [youw8.services.exposed.webservices.rest.MeasurementsResource] [ ] error occured:null

The important part in the stack trace is: org.hibernate.exception.SQLStateConverter.handledNonSpecificException. This indicates that an exception occurred that was not handled correctly and somewhere along the line the problem was caught, the transaction was rolled back, and then the rest of the business logic started performing without having any longer a transaction context.

At least, it's probably something like that.

It turned out to be a NullPointerException.