[Mulgara-general] Mulgara connection issues.

[Paul Gearon]

On Thu, Sep 3, 2009 at 12:54 PM, Joe Osowski<josowski at plos.org> wrote:
> I'm seeing some strange behavior here when connecting to a remote mulgara server.  It looks like we've got something misconfigured, but I haven't been able to nail it down yet.
>
> The ambra and mulgara instances that are installed on the same server and can talk to eachother fine.  But when I try to connect to this instance of mulgara from my development workstation, it just times out.  I turned up the debug logging for mulgara and this is what I see:
>
> I believe the interrupted exception is caused by the fact that I stopped my local ambra instance and the connection was closed.  It appears to be waiting for a write lock for some reason.
>
> Thoughts?

A closed connection *should* result in held resources being released
by the server, though there would be a delay. But maybe this isn't
happening? I can't really tell from your log here.

Is Ambra on the server still working fine? Alternatively, is the
Mulgara instance running a web server (which would let you execute
manual queries)? At least you could get some idea if the Mulgara
server has locked resources, or if the problem is confined to RMI.

Regards,
Paul
> 2009-09-03 09:35:03,120 DEBUG jotm> TransactionManager=org.objectweb.jotm.Current at 983d95 [RMI TCP Connection(22)-10.135.2.71 org.objectweb.jotm]
> 2009-09-03 09:35:03,120 DEBUG jta> timeout= 2147483647 [RMI TCP Connection(22)-10.135.2.71 org.objectweb.jotm.jta]
> 2009-09-03 09:35:03,120 DEBUG jta> Resetting transaction timeout= 2147483647 [RMI TCP Connection(22)-10.135.2.71 org.objectweb.jotm.jta]
> 2009-09-03 09:35:03,704 DEBUG MulgaraXAResourceContext> Performing setTransactionTimeout [RMI TCP Connection(22)-10.135.2.71 org.mulgara.resolver.MulgaraXAResourceContext]
> 2009-09-03 09:35:03,739 DEBUG MulgaraXAResourceContext> Performing start(TMNOFLAGS): :1114926712:-970499552:-408998783: [RMI TCP Connection(22)-10.135.2.71 org.mulgara.resolver.MulgaraXAResourceContext]
> 2009-09-03 09:35:16,156 DEBUG TransactionLogger> Flushed log file = '/var/lib/topaz/mulgara.tx.log'  [TransactionLogger-Worker org.topazproject.mulgara.resolver.TransactionLogger]
> 2009-09-03 09:35:43,731 DEBUG SessionWrapperRemoteSession> Closing unreferenced remote session org.mulgara.resolver.DatabaseSession at 127d15e [RMI Unreferenced-4 org.mulgara.server.rmi.SessionWrapperRemoteSession]
> 2009-09-03 09:35:43,731 DEBUG DatabaseSession> Closing session [RMI Unreferenced-4 org.mulgara.resolver.DatabaseSession]
> 2009-09-03 09:35:43,731 ERROR MulgaraXAResourceContext> Failed to create transaction [RMI TCP Connection(22)-10.135.2.71 org.mulgara.resolver.MulgaraXAResourceContext]
> org.mulgara.query.MulgaraTransactionException: Interrupted while waiting for write lock
>        at org.mulgara.resolver.MulgaraTransactionManager.obtainWriteLock(MulgaraTransactionManager.java:97)
>        at org.mulgara.resolver.MulgaraExternalTransactionFactory.createTransaction(MulgaraExternalTransactionFactory.java:93)
>        at org.mulgara.resolver.MulgaraXAResourceContext$MulgaraXAResource.start(MulgaraXAResourceContext.java:371)
>        at org.mulgara.server.rmi.XAResourceWrapperRemoteXAResource.start(XAResourceWrapperRemoteXAResource.java:100)
>        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
>        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
>        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
>        at java.lang.reflect.Method.invoke(Method.java:585)
>        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:294)
>        at sun.rmi.transport.Transport$1.run(Transport.java:153)
>        at java.security.AccessController.doPrivileged(Native Method)
>        at sun.rmi.transport.Transport.serviceCall(Transport.java:149)
>        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:466)
>        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:707)
>        at java.lang.Thread.run(Thread.java:595)
> Caused by: java.lang.InterruptedException
>        at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.reportInterruptAfterWait(AbstractQueuedSynchronizer.java:1815)
>        at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1850)
>        at org.mulgara.resolver.MulgaraTransactionManager.obtainWriteLock(MulgaraTransactionManager.java:95)
>        ... 14 more
> 2009-09-03 09:35:43,733 DEBUG MulgaraTransactionFactory> Cleaning up any stale transactions on session close [RMI Unreferenced-4 org.mulgara.resolver.MulgaraTransactionFactory]
> 2009-09-03 09:35:43,733 DEBUG MulgaraTransactionFactory> Session does not hold write-lock [RMI Unreferenced-4 org.mulgara.resolver.MulgaraTransactionFactory]
>
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