[infinispan-dev] frequent stack in testsuite

Galder Zamarreño galder at redhat.com
Fri Jun 10 10:14:20 EDT 2011 

On Jun 10, 2011, at 3:51 PM, Sanne Grinovero wrote:

> 2011/6/10 Galder Zamarreño <galder at redhat.com>:
>> 
>> On Jun 10, 2011, at 11:42 AM, Sanne Grinovero wrote:
>> 
>>> 2011/6/10 Galder Zamarreño <galder at redhat.com>:
>>>> 
>>>> On Jun 9, 2011, at 5:47 PM, Manik Surtani wrote:
>>>> 
>>>>> +1 to writing the error marker to the stream. At least prevent false alarms.
>>>>> 
>>>>> Re: unit testing our externalizers, Galder, any thoughts there?
>>>> 
>>>> The debugging done by Sanne/Dan seems to be correct.
>>>> 
>>>> EOFException is simply saying: "hey, i'm expecting all these bytes but the stream finished before I could read them all"
>>>> 
>>>> This generally means that the side generating the stream encountered an issue, and that's precisely what happens on the generation side.
>>>> 
>>>> The receiver side cannot do much here other than say: "hey, i don't have all the bytes" - and that's precisely what the EOFException is doing.
>>>> 
>>>> I think the error marker could be complicated to implement (i.e. imagine expecting to read a byte and instead getting an ERROR marker). What would be much easier to do is for VersionAwareMarshaller or GenericJBossMarshaller to provide more hints about what's wrong. So, they could hide the inner details of the EOFException and launder it into something that's clearer to the user:
>>>> 
>>>> "The stream ended unexpectedly, please check for any errors where the stream was generated"
>>>> 
>>>> The right exception here is still an EOFException.
>>>> 
>>>> That's all the receiver side can do.
>>> 
>>> Agreed that's reasonable on the receiver side, and of course we can't
>>> control the network so while we can't always prevent it, can we still
>>> try to not send incomplete streams from the sending side?
>> 
>> Isn't that complicating the stream reading code quite a bit?
> 
> Hi Galder, I'm not sure to what you're referring to. I was not
> proposing to change anything on the reader side, just - if possible as
> I don't know this code - to try not sending anything if we fail to
> build a proper stream (instead of sending a broken stream). That is of
> course feasible only if you've not started transmitting already.

That doesn't work for state based streams, such as state transfer or rehashing. You can't just wait to build the entire stream and then send it.

The error we're seeing here is precisely in one those use cases.

In pretty much the rest of marshalling cases, we build the stream and then we send it.

> 
> Sanne
> 
>> 
>> I can only imagine being possible to do that with a catch throwable and then have an ERROR object/marker of some sort.
>> 
>> Then, everytime you read something you'd have to check whether it's a the error object or marker. Now, how do you compare an int or a byte with an Object? If it's a marker, which marker? It could just happen that the marker (i.e. a byte) it's actually part of the correct stream.
>> 
>> Besides, what do we gain with this? Nothing, the receiver side is still gonna say the same, "something went wrong on the client side"
>> 
>>> 
>>> Sanne
>>> 
>>>> 
>>>>> 
>>>>> Sent from my mobile phone
>>>>> 
>>>>> On 9 Jun 2011, at 16:24, Dan Berindei <dan.berindei at gmail.com> wrote:
>>>>> 
>>>>>> I don't think it's an externalizer issue, as I also see some
>>>>>> exceptions on the node that generates state:
>>>>>> 
>>>>>> 2011-06-09 18:16:18,250 ERROR
>>>>>> [org.infinispan.remoting.transport.jgroups.JGroupsTransport]
>>>>>> (STREAMING_STATE_TRANSFER-sender-1,Infinispan-Cluster,NodeA-57902)
>>>>>> ISPN00095: Caught while responding to state transfer request
>>>>>> org.infinispan.statetransfer.StateTransferException:
>>>>>> java.util.concurrent.TimeoutException:
>>>>>> STREAMING_STATE_TRANSFER-sender-1,Infinispan-Cluster,NodeA-57902 could
>>>>>> not obtain exclusive processing lock after 10 seconds.  Locks in
>>>>>> question are java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock at a35c90[Read
>>>>>> locks = 1] and java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock at 111fb7f[Unlocked]
>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.generateState(StateTransferManagerImpl.java:177)
>>>>>>       at org.infinispan.remoting.InboundInvocationHandlerImpl.generateState(InboundInvocationHandlerImpl.java:248)
>>>>>>       at org.infinispan.remoting.transport.jgroups.JGroupsTransport.getState(JGroupsTransport.java:585)
>>>>>>       at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.handleUpEvent(MessageDispatcher.java:690)
>>>>>>       at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:771)
>>>>>>       at org.jgroups.JChannel.up(JChannel.java:1484)
>>>>>>       at org.jgroups.stack.ProtocolStack.up(ProtocolStack.java:1074)
>>>>>>       at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER$StateProviderHandler.process(STREAMING_STATE_TRANSFER.java:651)
>>>>>>       at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER$StateProviderThreadSpawner$1.run(STREAMING_STATE_TRANSFER.java:580)
>>>>>>       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
>>>>>>       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
>>>>>>       at java.lang.Thread.run(Thread.java:636)
>>>>>> Caused by: java.util.concurrent.TimeoutException:
>>>>>> STREAMING_STATE_TRANSFER-sender-1,Infinispan-Cluster,NodeA-57902 could
>>>>>> not obtain exclusive processing lock after 10 seconds.  Locks in
>>>>>> question are java.util.concurrent.locks.ReentrantReadWriteLock$ReadLock at a35c90[Read
>>>>>> locks = 1] and java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock at 111fb7f[Unlocked]
>>>>>>       at org.infinispan.remoting.transport.jgroups.JGroupsDistSync.acquireProcessingLock(JGroupsDistSync.java:100)
>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.generateTransactionLog(StateTransferManagerImpl.java:204)
>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.generateState(StateTransferManagerImpl.java:167)
>>>>>>       ... 11 more
>>>>>> 
>>>>>> I guess we could write an error marker in the stream to prevent the
>>>>>> EOFException on the receiving side, but the end result would be the
>>>>>> same.
>>>>>> 
>>>>>> Dan
>>>>>> 
>>>>>> 
>>>>>> On Thu, Jun 9, 2011 at 5:58 PM, Sanne Grinovero <sanne at infinispan.org> wrote:
>>>>>>> Hello all,
>>>>>>> if I happen to look at the console while the tests are running, I see
>>>>>>> this exception popup very often:
>>>>>>> 
>>>>>>> 2011-06-09 15:32:18,092 ERROR [JGroupsTransport]
>>>>>>> (Incoming-1,Infinispan-Cluster,NodeB-32230) ISPN00096: Caught while
>>>>>>> requesting or applying state
>>>>>>> org.infinispan.statetransfer.StateTransferException:
>>>>>>> java.io.EOFException: Read past end of file
>>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.applyState(StateTransferManagerImpl.java:333)
>>>>>>>       at org.infinispan.remoting.InboundInvocationHandlerImpl.applyState(InboundInvocationHandlerImpl.java:230)
>>>>>>>       at org.infinispan.remoting.transport.jgroups.JGroupsTransport.setState(JGroupsTransport.java:602)
>>>>>>>       at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.handleUpEvent(MessageDispatcher.java:711)
>>>>>>>       at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:771)
>>>>>>>       at org.jgroups.JChannel.up(JChannel.java:1441)
>>>>>>>       at org.jgroups.stack.ProtocolStack.up(ProtocolStack.java:1074)
>>>>>>>       at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER.connectToStateProvider(STREAMING_STATE_TRANSFER.java:523)
>>>>>>>       at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER.handleStateRsp(STREAMING_STATE_TRANSFER.java:462)
>>>>>>>       at org.jgroups.protocols.pbcast.STREAMING_STATE_TRANSFER.up(STREAMING_STATE_TRANSFER.java:223)
>>>>>>>       at org.jgroups.protocols.FRAG2.up(FRAG2.java:189)
>>>>>>>       at org.jgroups.protocols.FC.up(FC.java:479)
>>>>>>>       at org.jgroups.protocols.pbcast.GMS.up(GMS.java:891)
>>>>>>>       at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:246)
>>>>>>>       at org.jgroups.protocols.UNICAST.handleDataReceived(UNICAST.java:613)
>>>>>>>       at org.jgroups.protocols.UNICAST.up(UNICAST.java:294)
>>>>>>>       at org.jgroups.protocols.pbcast.NAKACK.up(NAKACK.java:703)
>>>>>>>       at org.jgroups.protocols.VERIFY_SUSPECT.up(VERIFY_SUSPECT.java:133)
>>>>>>>       at org.jgroups.protocols.FD.up(FD.java:275)
>>>>>>>       at org.jgroups.protocols.FD_SOCK.up(FD_SOCK.java:275)
>>>>>>>       at org.jgroups.protocols.MERGE2.up(MERGE2.java:209)
>>>>>>>       at org.jgroups.protocols.Discovery.up(Discovery.java:291)
>>>>>>>       at org.jgroups.protocols.TP.passMessageUp(TP.java:1102)
>>>>>>>       at org.jgroups.protocols.TP$IncomingPacket.handleMyMessage(TP.java:1658)
>>>>>>>       at org.jgroups.protocols.TP$IncomingPacket.run(TP.java:1640)
>>>>>>>       at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
>>>>>>>       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
>>>>>>>       at java.lang.Thread.run(Thread.java:662)
>>>>>>> Caused by: java.io.EOFException: Read past end of file
>>>>>>>       at org.jboss.marshalling.SimpleDataInput.eofOnRead(SimpleDataInput.java:126)
>>>>>>>       at org.jboss.marshalling.SimpleDataInput.readUnsignedByteDirect(SimpleDataInput.java:263)
>>>>>>>       at org.jboss.marshalling.SimpleDataInput.readUnsignedByte(SimpleDataInput.java:224)
>>>>>>>       at org.jboss.marshalling.river.RiverUnmarshaller.doReadObject(RiverUnmarshaller.java:209)
>>>>>>>       at org.jboss.marshalling.AbstractObjectInput.readObject(AbstractObjectInput.java:37)
>>>>>>>       at org.infinispan.marshall.jboss.GenericJBossMarshaller.objectFromObjectStream(GenericJBossMarshaller.java:192)
>>>>>>>       at org.infinispan.marshall.VersionAwareMarshaller.objectFromObjectStream(VersionAwareMarshaller.java:190)
>>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.processCommitLog(StateTransferManagerImpl.java:230)
>>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.applyTransactionLog(StateTransferManagerImpl.java:252)
>>>>>>>       at org.infinispan.statetransfer.StateTransferManagerImpl.applyState(StateTransferManagerImpl.java:322)
>>>>>>>       ... 27 more
>>>>>>> 
>>>>>>> But I'm not sure if it's an issue, as it seems tests are not failing.
>>>>>>> I consider a "Read past end of file" quite suspiciously looking; would
>>>>>>> it be possible to think that some internal Externalizer is writing
>>>>>>> less bytes than what it's attempting to read?
>>>>>>> Is there something clever I could do to understand which object the
>>>>>>> marshaller is trying to read when something like this is happening?
>>>>>>> I've found debugging this quite hard.
>>>>>>> 
>>>>>>> Also, it doesn't look like our externalizers have a good test
>>>>>>> coverage; They are likely implicitly tested as I assume that nothing
>>>>>>> would work if they aren't, but still it looks like we have no explicit
>>>>>>> tests for them?
>>>>>>> 
>>>>>>> Cheers,
>>>>>>> Sanne
>>>>>>> _______________________________________________
>>>>>>> infinispan-dev mailing list
>>>>>>> infinispan-dev at lists.jboss.org
>>>>>>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
>>>>>>> 
>>>>>> 
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>>>>> 
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>>>> 
>>>> --
>>>> Galder Zamarreño
>>>> Sr. Software Engineer
>>>> Infinispan, JBoss Cache
>>>> 
>>>> 
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>>> 
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>> 
>> --
>> Galder Zamarreño
>> Sr. Software Engineer
>> Infinispan, JBoss Cache
>> 
>> 
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--
Galder Zamarreño
Sr. Software Engineer
Infinispan, JBoss Cache

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