"Uncommitted transaction with id X found..." What does it mean?

[bobufuller30004]

I'm getting a pile of WARN logging during my application's start up...

...

2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 32973 found and discarded
2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 32979 found and discarded
2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 32985 found and discarded
2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 32991 found and discarded
2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 32997 found and discarded
2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 33003 found and discarded
2010-10-05 16:45:52,528 WARN  [org.hornetq.core.journal.impl.JournalImpl] Uncommitted transaction with id 33009 found and discarded

...

What does this warning mean? I took a peek at the source code, but it didn't reveal anything for me.

Thanks HornetQ Community!

[clebert.suconic]

You killed the server before committs were accepted by the journal, when the journal restarted and reloaded, it couldn't find commit for those Transactions. and it will ignore them since it needs to guarantee ACID.

If you killed the server for a test that's a normal scenario.

[bobufuller30004]

Are journals (where the persistent messages are stored?) being used even if my queues are configured without paging or durability?

<address-setting match="myQueue">
  <max-size-bytes>5242880</max-size-bytes>
  <address-full-policy>DROP</address-full-policy>
</address-setting>

<queue name="myQueue">
  <address>myQueue</address>
  <durable>false</durable>
</queue>

Thanks!

[clebert.suconic]

Persistent messages are always stored on the journal (after routed).

Read the paging chapter for more information.

[clebert.suconic]

So, if you don't used paging, persistent messages will obviously be stored on the journal.

[bobufuller30004]

Hmm, ok, still a bit confused about how things work, but that's not unsual.

> If you killed the server for a test that's a normal scenario.

I'm not 'killing' the server, but using CTRL-C to cleanly shut it down. Does the WARN logging mean something in that scenario? Perhaps I've missed something to ensure HornetQ shuts down gracefully?

[clebert.suconic]

Say you have your client holding forever on the commit, and then you shut down the server, you won't get the commit to the journal, when you restart that data will be rolled back.

The server will not wait you finish your transactions if you set it to shutdown.

If you see a scenario where you closed all your connections, committed all your data, you shutdown the system and still see those issues, I would recommend you to try trunk first, and if you still see an issue, please provide me a testcase.