PessimisticLockException instead of LockTimeoutException thrown on DB2V9 for ZOS
--------------------------------------------------------------------------------
Key: OPENJPA-1609
URL: https://issues.apache.org/jira/browse/OPENJPA-1609
Project: OpenJPA
Issue Type: Bug
Affects Versions: 2.0.0-beta3, 2.0.0-beta2, 2.0.0-beta, 2.0.0-M3, 2.0.0-M2,
2.0.0-M1
Environment: DB2V91 on z/OS
Reporter: Jody Grassel
Assignee: Jody Grassel
I am observing the following problem while working with OpenJPA 2.x on DB2v91
for z/OS:
When performing a EntityManager.find() with a lock timeout property set, I'm
expecting to receive a LockTimeoutException if my find operation fails to fetch
the data from the database within the specified timeout period. Instead of
getting the LockTimeoutException, I am getting a PessimisticLockException -- an
Exception that is considerably more severe then is expected.
I looked at the stack trace, and found the following information:
**Exception: Caught unexpected exception from find.
org.apache.openjpa.persistence.PessimisticLockException:Unable to obtain an
object lock on "null [java.lang.String]".
FailedObject: 1 [org.apache.openjpa.util.IntId] [java.lang.String]
at
org.apache.openjpa.jdbc.sql.DBDictionary.narrow(DBDictionary.java:4809)
at
org.apache.openjpa.jdbc.sql.DBDictionary.newStoreException(DBDictionary.java:4787)
at
org.apache.openjpa.jdbc.sql.DB2Dictionary.newStoreException(DB2Dictionary.java:563)
at
org.apache.openjpa.jdbc.sql.SQLExceptions.getStore(SQLExceptions.java:136)
at
org.apache.openjpa.jdbc.sql.SQLExceptions.getStore(SQLExceptions.java:86)
at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.initialize(JDBCStoreManager.java:339)
at
com.ibm.ws.persistence.jdbc.kernel.WsJpaJDBCStoreManager.initialize(WsJpaJDBCStoreManager.java:147)
at
org.apache.openjpa.kernel.DelegatingStoreManager.initialize(DelegatingStoreManager.java:111)
at
org.apache.openjpa.kernel.ROPStoreManager.initialize(ROPStoreManager.java:57)
at org.apache.openjpa.kernel.BrokerImpl.initialize(BrokerImpl.java:1005)
at org.apache.openjpa.kernel.BrokerImpl.find(BrokerImpl.java:963)
at org.apache.openjpa.kernel.BrokerImpl.find(BrokerImpl.java:880)
at
org.apache.openjpa.kernel.DelegatingBroker.find(DelegatingBroker.java:222)
at
org.apache.openjpa.persistence.EntityManagerImpl.find(EntityManagerImpl.java:496)
at
suite.r80.base.jpaspec.entitymanager.testlogic.FindLockTestLogic.testScenarioL009(FindLockTestLogic.java:2150)
...
Caused by: org.apache.openjpa.lib.jdbc.ReportingSQLException: DB2 SQL Error:
SQLCODE=-913, SQLSTATE=57033,
SQLERRMC=00C9008E;00000304;DSN00292.JPA20EME.X'00000002'.X'01', DRIVER=3.57.91
{prepstmnt 2135785293 SELECT t0.version, t1.id, t1.version, t1.ENTITYALAZY_ID,
t1.strData, t0.strData FROM JPA20EMEntityA t0 LEFT OUTER JOIN JPA20EMEntityC t1
ON t0.id = t1.ENTITYA_ID WHERE t0.id = ? optimize for 1 row FOR READ ONLY WITH
RR USE AND KEEP UPDATE LOCKS [params=(int) 1]} [code=-913, state=57033]
at
org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator.wrap(LoggingConnectionDecorator.java:257)
at
org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator.wrap(LoggingConnectionDecorator.java:241)
at
org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator.access$700(LoggingConnectionDecorator.java:70)
at
org.apache.openjpa.lib.jdbc.LoggingConnectionDecorator$LoggingConnection$LoggingPreparedStatement.executeQuery(LoggingConnectionDecorator.java:1063)
at
org.apache.openjpa.lib.jdbc.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:278)
at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager$CancelPreparedStatement.executeQuery(JDBCStoreManager.java:1706)
at
org.apache.openjpa.lib.jdbc.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:268)
at
org.apache.openjpa.jdbc.sql.SelectImpl.executeQuery(SelectImpl.java:471)
at org.apache.openjpa.jdbc.sql.SelectImpl.execute(SelectImpl.java:396)
at
com.ibm.ws.persistence.jdbc.sql.SelectImpl.execute(SelectImpl.java:77)
at org.apache.openjpa.jdbc.sql.SelectImpl.execute(SelectImpl.java:354)
at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.getInitializeStateResult(JDBCStoreManager.java:577)
at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.initializeState(JDBCStoreManager.java:379)
at
org.apache.openjpa.jdbc.kernel.JDBCStoreManager.initialize(JDBCStoreManager.java:334)
... 43 more
The problem is that OpenJPA does not properly process the combination of
SQLCODE=-913, SQLSTATE=57033, and SQLERRMC=00C9008E.
The RedBook "DB2 for z/OS Stored Procedures: Through the CALL and Beyond" page
188 states:
-913
UNSUCCESSFUL EXECUTION CAUSED BY DEADLOCK OR TIMEOUT. REASON CODE reason-code,
TYPE
OF RESOURCE resource-type, AND RESOURCE NAME resource-name
Explanation: The application was the victim in a deadlock or experienced a
time-out. The
reason code indicates whether a deadlock or time-out occurred.
SQLERRD(3) also contains the reason-code which indicates whether a deadlock or
time-out
occurred. The most common reason codes are:
00C90088 - deadlock
00C9008E - time-out
Response: The application should either commit or roll back to the previous
COMMIT. Then,
generally, the application should terminate. See message DSNT376I in DB2 UDB
for z/OS
Version 8 Messages and Codes, GC18-7422, for possible ways to avoid future
deadlocks or
time-outs.
The error being reported by DB2V9 on zOS is "SQLCODE=-913, SQLSTATE=57033,
SQLERRMC=00C9008E", which indicates that
the reason for the unsuccessful execution is a Timeout, not a Deadlock.
Presently, the DB2Dictionary.isFatalException() method does not support that
combination.
I've made a change to the isFatalException() method that considers that error
combination, and the expected LockTimeoutException now surfaces. I will post
the patch on to this JIRA in a few minutes.
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