Revision as of 10:47, 16 January 2009

Bug Analysis Document: 259993: Deadlock on em.find() on WebSphere 7.0.0.1

• Bugzilla Bug 259993

Document History

Overview

This bug describes the behavior and fix for an isssue where an em.find() on WebSphere 7.0.0.1 hangs indefinitly when attempting to acquire lock on the concurrencyManager on a cacheKey.

Exception

There is no exception until the tests are stopped or the server is restarted.

StackTrace

Query: DataModifyQuery(sql="CREATE TABLE CMP3_ENTITYD_SEQ (SEQ_NAME VARCHAR2(50) NOT NULL, SEQ_COUNT NUMBER(38) NULL, PRIMARY KEY (SEQ_NAME))")
[1/15/09 17:48:15:936 EST] 0000000e ThreadMonitor W   WSVR0605W: Thread "ORB.thread.pool : 1" (00000022) has been active for 670586 milliseconds and may be hung.  There is/are 2 thread(s) in total in the server that may be hung.
	at java.lang.Object.wait(Native Method)
	at java.lang.Object.wait(Object.java:196)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkIdentityMapAccessor.getAndCloneCacheKeyFromParent(UnitOfWorkIdentityMapAccessor.java:146)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkIdentityMapAccessor.getFromIdentityMap(UnitOfWorkIdentityMapAccessor.java:110)
	at org.eclipse.persistence.internal.queries.ExpressionQueryMechanism.checkCacheForObject(ExpressionQueryMechanism.java:730)
	at org.eclipse.persistence.queries.ReadObjectQuery.checkEarlyReturnImpl(ReadObjectQuery.java:229)
	at org.eclipse.persistence.queries.ObjectLevelReadQuery.checkEarlyReturn(ObjectLevelReadQuery.java:627)
	at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:613)
	at org.eclipse.persistence.queries.ObjectLevelReadQuery.execute(ObjectLevelReadQuery.java:891)
	at org.eclipse.persistence.queries.ReadObjectQuery.execute(ReadObjectQuery.java:397)
	at org.eclipse.persistence.queries.ObjectLevelReadQuery.executeInUnitOfWork(ObjectLevelReadQuery.java:954)
	at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.internalExecuteQuery(UnitOfWorkImpl.java:2651)
	at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1181)
	at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1165)
	at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1125)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.executeQuery(EntityManagerImpl.java:571)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.findInternal(EntityManagerImpl.java:516)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.find(EntityManagerImpl.java:431)
	at org.eclipse.persistence.internal.jpa.EntityManagerImpl.find(EntityManagerImpl.java:339)
	at com.ibm.ws.jpa.management.JPATxEmInvocation.find(JPATxEmInvocation.java:211)
	at com.ibm.ws.jpa.management.JPAEntityManager.find(JPAEntityManager.java:175)
	at org.eclipse.persistence.testing.tests.jpa.relationships.VirtualAttributeTestSuite.testReadVirtualAttribute(VirtualAttributeTestSuite.java:76)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:45)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
	at java.lang.reflect.Method.invoke(Method.java:599)
	at junit.framework.TestCase.runTest(TestCase.java:154)
	at junit.framework.TestCase.runBare(TestCase.java:127)
	at org.eclipse.persistence.testing.framework.junit.JUnitTestCase.runBareServer(JUnitTestCase.java:391)
	at org.eclipse.persistence.testing.framework.server.TestRunnerBean.runTest(TestRunnerBean.java:87)
	at org.eclipse.persistence.testing.framework.server.EJSRemote0SLTestRunner_ed643271.runTest(EJSRemote0SLTestRunner_ed643271.java)
	at org.eclipse.persistence.testing.framework.server._EJSRemote0SLTestRunner_ed643271_Tie.runTest(_EJSRemote0SLTestRunner_ed643271_Tie.java)
	at org.eclipse.persistence.testing.framework.server._EJSRemote0SLTestRunner_ed643271_Tie._invoke(_EJSRemote0SLTestRunner_ed643271_Tie.java)
	at com.ibm.CORBA.iiop.ServerDelegate.dispatchInvokeHandler(ServerDelegate.java:622)
	at com.ibm.CORBA.iiop.ServerDelegate.dispatch(ServerDelegate.java:475)
	at com.ibm.rmi.iiop.ORB.process(ORB.java:504)
	at com.ibm.CORBA.iiop.ORB.process(ORB.java:1571)
	at com.ibm.rmi.iiop.Connection.respondTo(Connection.java:2771)
	at com.ibm.rmi.iiop.Connection.doWork(Connection.java:2640)
	at com.ibm.rmi.iiop.WorkUnitImpl.doWork(WorkUnitImpl.java:63)
	at com.ibm.ejs.oa.pool.PooledThread.run(ThreadPool.java:118)
	at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1527)

Concepts

JPA Specification Notes

JPA 1.0 Specification

JPA 2.0 Specification

Reproduction

Prerequisites

Data Model

Use Case 1: Persist unmanaged entity (with @PrePersist query) referenced by managed entity

StackTrace

Logs

Analysis Constraints

Concurrency and Thread Safety

Design / Functionality

Alternative 1:

Implementation

Logging

Testing

API

GUI

Config files

Documentation

Open Issues

Decisions

Future Considerations

During the research for this bug, the following items were identified as out of scope but are captured here as potential future enhancements. If agreed upon during the review process these should be logged in the bug system.

References

• EclipseLink Fisheye Revision pending