[infinispan-issues] [JBoss JIRA] (ISPN-2410) A PrepareCommand forwarded back to the originator can time out waiting on a key already locked by itself

[Dan Berindei (JIRA)]

Dan Berindei created ISPN-2410:
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             Summary: A PrepareCommand forwarded back to the originator can time out waiting on a key already locked by itself
                 Key: ISPN-2410
                 URL: https://issues.jboss.org/browse/ISPN-2410
             Project: Infinispan
          Issue Type: Bug
          Components: State transfer
    Affects Versions: 5.2.0.Beta2
            Reporter: Dan Berindei
            Assignee: Dan Berindei
            Priority: Critical
             Fix For: 5.2.0.CR1


If a rebalance happens while a prepare command is executing on a remote node, and the originator has become an owner, it makes sense to forward the command back to the originator to lock the keys (or just add them to the backup locks list).

However, we don't keep the old consistent hashes around, so we don't know if the originator became an owner after invoking the remote command or was already an owner. So if the topology changed, we always forward the prepare back to the owner.

Back on the originator, minTxTopologyId < currentTopologyId, so the prepare command has to wait for all the backup locks from pending transactions to be released. The problem is that we wait for the current transaction as well, causing a deadlock.

Seen in OnePhaseXATest:

{noformat}
18:07:46,873 TRACE (testng-OnePhaseXATest:TestCache) [RpcManagerImpl] NodeA-46125 broadcasting call PrepareCommand {modifications=[PutKeyValueCommand{key=key0, value=value, flags=null, putIfAbsent=false, lifespanMillis=-1, maxIdleTimeMillis=-1}], onePhaseCommit=false, gtx=GlobalTransaction:<NodeA-46125>:4353:local, cacheName='TestCache', topologyId=-1} to recipient list null
18:07:46,873 DEBUG (transport-thread-2,NodeA:TestCache) [LocalTopologyManagerImpl] Updating local consistent hash(es) for cache TestCache: new topology = CacheTopology{id=2, currentCH=ReplicatedConsistentHash{members=[NodeA-46125, NodeB-49450]}, pendingCH=null}
18:07:46,894 TRACE (OOB-1,ISPN,NodeB-49450:TestCache) [StateTransferManagerImpl] Forwarding command PrepareCommand {modifications=[PutKeyValueCommand{key=key0, value=value, flags=null, putIfAbsent=false, lifespanMillis=-1, maxIdleTimeMillis=-1}], onePhaseCommit=false, gtx=GlobalTransaction:<NodeA-46125>:4353:remote, cacheName='TestCache', topologyId=2} to new targets [NodeA-46125]
18:07:46,935 TRACE (OOB-3,ISPN,NodeA-46125:TestCache) [StateTransferInterceptor] handleTopologyAffectedCommand for command PrepareCommand {modifications=[PutKeyValueCommand{key=key0, value=value, flags=null, putIfAbsent=false, lifespanMillis=-1, maxIdleTimeMillis=-1}], onePhaseCommit=false, gtx=GlobalTransaction:<NodeA-46125>:4353:remote, cacheName='TestCache', topologyId=2}, originLocal=false
18:07:46,935 TRACE (OOB-3,ISPN,NodeA-46125:TestCache) [AbstractCacheTransaction] Transaction gtx=GlobalTransaction:<NodeA-46125>:4353:local potentially locks key key0? true
18:08:16,874 TRACE (testng-OnePhaseXATest:TestCache) [RpcManagerImpl] replication exception: 
org.infinispan.CacheException: org.jgroups.TimeoutException: timeout sending message to NodeB-49450
{noformat}



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