4 Replies Latest reply on Sep 24, 2009 12:35 PM by manik

MVCCLockManager.lockAndRecord ignores the values of Invocati

veklov Sep 4, 2009 6:24 AM

Hi

As you can see from the below log:
* actual lock acquisition timeout in lockAndRecord is 10 seconds which equals to timeout on the cache level. (time between MVCCLockManager.lockAndRecord and MVCCLockingInterceptor.doAfterCall).
* the value of InvocationContext.getLockAcquisitionTimeout is 0. (exception message "... Unable to acquire lock on Fqn [...] after [0] milliseconds ..." produced by MVCCNodeHelper.acquireLock)

04.09.09 12:56:16.539 MSD [17] FINEST org.jboss.cache.lock.MVCCLockManager.lockAndRecord - Attempting to lock /java.lang.Integer/k
04.09.09 12:56:26.539 MSD [17] FINEST org.jboss.cache.interceptors.MVCCLockingInterceptor.doAfterCall - Nothing to do since there are no modifications in scope.
04.09.09 12:56:26.539 MSD [17] FINEST org.jboss.cache.InvocationContext.throwIfNeeded - There was a problem handling this request, but failSilently was set, so suppressing exception - org.jboss.cache.lock.TimeoutException: Unable to acquire lock on Fqn [/java.lang.Integer/k] after [0] milliseconds for requestor [Thread[Thread-1,5,main]]! Lock held by [GlobalTransaction:<10.139.132.111:2698>:0]
at org.jboss.cache.mvcc.MVCCNodeHelper.acquireLock(MVCCNodeHelper.java:159)
at org.jboss.cache.mvcc.MVCCNodeHelper.wrapNodeForWriting(MVCCNodeHelper.java:236)
at org.jboss.cache.mvcc.MVCCNodeHelper.wrapNodeForWriting(MVCCNodeHelper.java:186)

In particular this affects behaviour of Cache.putFromExternalRead

1. Re: MVCCLockManager.lockAndRecord ignores the values of Invo

veklov Sep 4, 2009 6:29 AM (in response to veklov)

The version of the cache is 3.2.0.

The full subject is "MVCCLockManager.lockAndRecord ignores the values of InvocationContext.getLockAcquisitionTimeout"
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2. Re: MVCCLockManager.lockAndRecord ignores the values of Invo

manik Sep 7, 2009 6:56 AM (in response to veklov)

Please see the javadocs for Cache#putForExternalRead()
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3. Re: MVCCLockManager.lockAndRecord ignores the values of Invo

veklov Sep 7, 2009 7:52 AM (in response to veklov)

I see the contradiction to the javadocs for Cache#putForExternalRead().

According to the javadocs: "0ms lock timeout to prevent any blocking here either. If the lock is not acquired, this method is a no-op, and swallows the timeout exception."

But as you can see from the provided log the actual time out is 10 seconds.

I think that the behaviour of putForExternalRead is implemented through setting InvocationContext.lockAcquisitionTimeout to 0, but MVCCLockManager.lockAndRecord ignores this value.
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4. Re: MVCCLockManager.lockAndRecord ignores the values of Invo

manik Sep 24, 2009 12:35 PM (in response to veklov)

Hi thanks for reporting, this is definitely a bug.

See https://jira.jboss.org/jira/browse/JBCACHE-1547
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