[jbosscache-dev] LockParentForChildInsertRemove and PessimisticLocking

Brian Stansberry brian.stansberry at redhat.com
Wed Aug 5 09:42:25 EDT 2009


Paul and I have been poking through code trying to diagnose the issue 
that led to this thread for quite a while yesterday. Time to throw it 
out there and see if anyone hopefully spots something:

This is web session replication with buddy replication. The 
"LockParentForChildInsertRemove" property isn't configured on the cache, 
so the default "false" should be in effect. A thread trying to execute a 
remote DataGravitationCleanupCommand on a session node fails upgrading 
to a write lock on fqn /BUDDY_MANAGER.[1] We can't understand why it 
would want a WL.

Looking at the PessimisticNodeBasedLockManager code, the only reasons I 
see why a WL would be requested here are:

1) The invocation created the previously non-existent /BUDDY_MANAGER 
node in order to execute the remove of the 
great-great-great-great-grandchild. Highly unlikely in general and 
logging shows another thread successfully doing a put on a different 
great-great-great-great-grandchild a millisecond earlier. (Also other 
test runs w/ less verbose logging showed failures getting a WL on fqn / 
which of course exists).

2) In call to PNBLM.writeLockNeeded(...) 
currentNode.isLockForChildInsertRemove() is returning "true". Which 
AFAICT it shouldn't be.

[1] The logging from the thread:

[JBoss] 20:29:27,488 TRACE 
[org.jboss.cache.marshall.CommandAwareRpcDispatcher] 
(Incoming-5,10.34.32.154:46064) Executing command: 
DataGravitationCleanupCommand{fqn=/JSESSION/st_localhost/wUaU4FhUzWcuiDEjkJzDiQ__, 
backup=/_BUDDY_BACKUP_/10.34.32.155_41754:DEAD/1/JSESSION/st_localhost/wUaU4FhUzWcuiDEjkJzDiQ__} 
[sender=10.34.32.153:24595]
[JBoss] 20:29:27,489 TRACE 
[org.jboss.cache.marshall.CommandAwareRpcDispatcher] 
(Incoming-5,10.34.32.154:46064) This is a non-visitable command - so 
performing directly and not via the invoker.
[JBoss] 20:29:42,497 ERROR 
[org.jboss.cache.lock.ReadWriteLockWithUpgrade] 
(Incoming-5,10.34.32.154:46064) upgradeLock(): failed
[JBoss] 20:29:42,500 TRACE 
[org.jboss.cache.marshall.CommandAwareRpcDispatcher] 
(Incoming-5,10.34.32.154:46064) Problems invoking command.
[JBoss] org.jboss.cache.lock.UpgradeException: upgrade lock for 
/_BUDDY_BACKUP_ could not be acquired after 15000 ms. Lock map ownership 
Read lock owners: [GlobalTransaction:<10.34.32.153:24595>:70, 
GlobalTransaction:<10.34.32.153:24595>:69]
[JBoss] Write lock owner: null
[JBoss]  (caller=Thread[Incoming-5,10.34.32.154:46064,5,Thread Pools], 
lock info: read owners=[GlobalTransaction:<10.34.32.153:24595>:70, 
GlobalTransaction:<10.34.32.153:24595>:69] (activeReaders=2, 
activeWriter=null, waitingReaders=1, waitingWriters=0, waitingUpgrader=0))
[JBoss] 	at 
org.jboss.cache.lock.IdentityLock.acquireWriteLock0(IdentityLock.java:227)
[JBoss] 	at 
org.jboss.cache.lock.IdentityLock.acquireWriteLock(IdentityLock.java:176)
[JBoss] 	at org.jboss.cache.lock.IdentityLock.acquire(IdentityLock.java:503)
[JBoss] 	at 
org.jboss.cache.lock.PessimisticNodeBasedLockManager.acquireNodeLock(PessimisticNodeBasedLockManager.java:260)
[JBoss] 	at 
org.jboss.cache.lock.PessimisticNodeBasedLockManager.lock(PessimisticNodeBasedLockManager.java:169)
[JBoss] 	at 
org.jboss.cache.lock.PessimisticNodeBasedLockManager.lockPessimistically(PessimisticNodeBasedLockManager.java:97)
[JBoss] 	at 
org.jboss.cache.interceptors.PessimisticLockInterceptor.handleRemoveNodeCommand(PessimisticLockInterceptor.java:265)
[JBoss] 	at 
org.jboss.cache.interceptors.base.PrePostProcessingCommandInterceptor.visitRemoveNodeCommand(PrePostProcessingCommandInterceptor.java:126)
[JBoss] 	at 
org.jboss.cache.commands.write.RemoveNodeCommand.acceptVisitor(RemoveNodeCommand.java:125)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:116)
[JBoss] 	at 
org.jboss.cache.interceptors.ReplicationInterceptor.handleCrudMethod(ReplicationInterceptor.java:148)
[JBoss] 	at 
org.jboss.cache.interceptors.ReplicationInterceptor.visitRemoveNodeCommand(ReplicationInterceptor.java:125)
[JBoss] 	at 
org.jboss.cache.commands.write.RemoveNodeCommand.acceptVisitor(RemoveNodeCommand.java:125)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:116)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.handleDefault(CommandInterceptor.java:131)
[JBoss] 	at 
org.jboss.cache.commands.AbstractVisitor.visitRemoveNodeCommand(AbstractVisitor.java:75)
[JBoss] 	at 
org.jboss.cache.commands.write.RemoveNodeCommand.acceptVisitor(RemoveNodeCommand.java:125)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:116)
[JBoss] 	at 
org.jboss.cache.interceptors.TxInterceptor.attachGtxAndPassUpChain(TxInterceptor.java:301)
[JBoss] 	at 
org.jboss.cache.interceptors.TxInterceptor.handleDefault(TxInterceptor.java:283)
[JBoss] 	at 
org.jboss.cache.commands.AbstractVisitor.visitRemoveNodeCommand(AbstractVisitor.java:75)
[JBoss] 	at 
org.jboss.cache.commands.write.RemoveNodeCommand.acceptVisitor(RemoveNodeCommand.java:125)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:116)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.handleDefault(CommandInterceptor.java:131)
[JBoss] 	at 
org.jboss.cache.commands.AbstractVisitor.visitRemoveNodeCommand(AbstractVisitor.java:75)
[JBoss] 	at 
org.jboss.cache.commands.write.RemoveNodeCommand.acceptVisitor(RemoveNodeCommand.java:125)
[JBoss] 	at 
org.jboss.cache.interceptors.base.CommandInterceptor.invokeNextInterceptor(CommandInterceptor.java:116)
[JBoss] 	at 
org.jboss.cache.interceptors.InvocationContextInterceptor.handleAll(InvocationContextInterceptor.java:178)
[JBoss] 	at 
org.jboss.cache.interceptors.InvocationContextInterceptor.visitRemoveNodeCommand(InvocationContextInterceptor.java:88)
[JBoss] 	at 
org.jboss.cache.commands.write.RemoveNodeCommand.acceptVisitor(RemoveNodeCommand.java:125)
[JBoss] 	at 
org.jboss.cache.interceptors.InterceptorChain.invoke(InterceptorChain.java:287)
[JBoss] 	at 
org.jboss.cache.commands.remote.DataGravitationCleanupCommand.executeRemove(DataGravitationCleanupCommand.java:151)
[JBoss] 	at 
org.jboss.cache.commands.remote.DataGravitationCleanupCommand.perform(DataGravitationCleanupCommand.java:105)
[JBoss] 	at 
org.jboss.cache.marshall.CommandAwareRpcDispatcher.executeCommand(CommandAwareRpcDispatcher.java:305)
[JBoss] 	at 
org.jboss.cache.marshall.CommandAwareRpcDispatcher.handle(CommandAwareRpcDispatcher.java:242)
[JBoss] 	at 
org.jgroups.blocks.RequestCorrelator.handleRequest(RequestCorrelator.java:637)
[JBoss] 	at 
org.jgroups.blocks.RequestCorrelator.receiveMessage(RequestCorrelator.java:545)
[JBoss] 	at 
org.jgroups.blocks.RequestCorrelator.receive(RequestCorrelator.java:368)
[JBoss] 	at 
org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:775)
[JBoss] 	at org.jgroups.JChannel.up(JChannel.java:1339)
[JBoss] 	at org.jgroups.stack.ProtocolStack.up(ProtocolStack.java:462)
[JBoss] 	at org.jgroups.protocols.pbcast.FLUSH.up(FLUSH.java:432)
[JBoss] 	at 
org.jgroups.protocols.pbcast.STATE_TRANSFER.up(STATE_TRANSFER.java:144)
[JBoss] 	at org.jgroups.protocols.FRAG2.up(FRAG2.java:188)
[JBoss] 	at org.jgroups.protocols.FC.up(FC.java:473)
[JBoss] 	at org.jgroups.protocols.pbcast.GMS.up(GMS.java:824)
[JBoss] 	at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:233)
[JBoss] 	at 
org.jgroups.protocols.UNICAST.handleDataReceived(UNICAST.java:616)
[JBoss] 	at org.jgroups.protocols.UNICAST.up(UNICAST.java:282)
[JBoss] 	at org.jgroups.protocols.pbcast.NAKACK.up(NAKACK.java:758)
[JBoss] 	at org.jgroups.protocols.VERIFY_SUSPECT.up(VERIFY_SUSPECT.java:167)
[JBoss] 	at org.jgroups.protocols.FD.up(FD.java:284)
[JBoss] 	at org.jgroups.protocols.FD_SOCK.up(FD_SOCK.java:309)
[JBoss] 	at org.jgroups.protocols.MERGE2.up(MERGE2.java:144)
[JBoss] 	at org.jgroups.protocols.Discovery.up(Discovery.java:264)
[JBoss] 	at org.jgroups.protocols.PING.up(PING.java:273)
[JBoss] 	at org.jgroups.protocols.TP$ProtocolAdapter.up(TP.java:2327)
[JBoss] 	at org.jgroups.protocols.TP.passMessageUp(TP.java:1261)
[JBoss] 	at org.jgroups.protocols.TP.access$100(TP.java:49)
[JBoss] 	at 
org.jgroups.protocols.TP$IncomingPacket.handleMyMessage(TP.java:1838)
[JBoss] 	at org.jgroups.protocols.TP$IncomingPacket.run(TP.java:1817)
[JBoss] 	at 
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
[JBoss] 	at 
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
[JBoss] 	at java.lang.Thread.run(Thread.java:619)

Manik Surtani wrote:
> 
> On 4 Aug 2009, at 21:28, Brian Stansberry wrote:
> 
>> Continuing dialogue with myself. :)
>>
>> I've found the logic in PessimisticNodeBasedLockManager where the
>> LockParentForChildInsertRemove configuration is meant to be coming
>> through via the Node.
> 
> Yes, this is because you can override this on a per-node basis.
> 
>> In our testing we're seeing cases where write
>> locks are being acquired on parent nodes, which isn't the intent. I'll
>> dig further.
>>
>> Brian Stansberry wrote:
>>> https://jira.jboss.org/jira/browse/JBCACHE-1527
>>>
>>> Brian Stansberry wrote:
>>>> From looking at the JBC 3 code, it seems the
>>>> LockParentForChildInsertRemove configuration is no longer respected for
>>>> pessimistic locking.  I can't trace any path from the property in
>>>> Configuration to code that uses it.
>>>> PessimisticLockInterceptor.handlePutCommand, handleMoveCommand and
>>>> handleRemoveNodeCommand all always tell the lock manager to lock
>>>> parents. handleEvictFqnCommand always tells the lock manager not to 
>>>> lock
>>>> parents.
>>>>
>>>> This is causing failures in buddy replication testing when nodes
>>>> join/leave clusters under load. There's a lot of data gravitation plus
>>>> stuff like migrating defunct backup trees to "DEAD" regions. Too much
>>>> contention for parent level locks.
>>>>
>>>> Plus locking on the structural parent to add/remove session nodes will
>>>> suck for the session caching use case.
>>>>
>>>
>>>
>>
>>
>> -- 
>> Brian Stansberry
>> Lead, AS Clustering
>> JBoss by Red Hat
>> _______________________________________________
>> jbosscache-dev mailing list
>> jbosscache-dev at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/jbosscache-dev
> 
> -- 
> Manik Surtani
> manik at jboss.org
> Lead, Infinispan
> Lead, JBoss Cache
> http://www.infinispan.org
> http://www.jbosscache.org
> 
> 
> 
> 


-- 
Brian Stansberry
Lead, AS Clustering
JBoss by Red Hat


More information about the jbosscache-dev mailing list