[
https://issues.apache.org/activemq/browse/AMQ-2149?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=50475#action_50475
]
Dejan Bosanac commented on AMQ-2149:
------------------------------------
Just some heads up.
It turns out that with <systemUsage> on you can reproduce this problem even
without restarting the broker, so the first step would be turn it off in this
case, until we find the cause of this problem.
In this configuration it will not be lost messages for a fair number of
consumers (like 10 in your original test case). Though you may experience some
duplicate messages. Duplicates are normal in the failover situations and they
are usually handled by the connection audit itself. The problem is that in this
case the duplicate messages are not in the default 2k audit window so they
reach the consumer. I filled the issue to make this window size configurable
(https://issues.apache.org/activemq/browse/AMQ-2160), but until then you can
add a bit of logic in your consumer to skip these messages.
For a large number of consumers this will still fail for the default broker
shutdown rate of 20 secs, but increasing it to 60 secs or more makes this test
runs fine for a quite a while. We'll keep investigating it further, but maybe
this could help you get started. Can you post back your test results with these
workarounds?
Thanks
Dejan
> Shared Filesystem Master Slave: missing messages
> ------------------------------------------------
>
> Key: AMQ-2149
> URL: https://issues.apache.org/activemq/browse/AMQ-2149
> Project: ActiveMQ
> Issue Type: Bug
> Affects Versions: 5.2.0
> Environment: Ubuntu Linux 8.10 AMD64, Sun JDK 1.6.0.10
> Reporter: Aaron Riekenberg
> Attachments: activemq.log, activemq.xml, MasterSlaveTest.java,
> MasterSlaveTestWithTransactions.java, run_master_slave_brokers.sh
>
>
> I'm finding occasionally messages are not delivered in order in a shared
> filesystem master slave setup when the master fails and the slave takes over.
> I'm running a simple test on one physical machine where the shared
> filesystem is on a single disk (no SAN currently involved).
> I'm attaching a shell script (run_master_slave_brokers.sh) that starts a
> master and slave broker in the same directory, sleeps 20 seconds, kills the
> master, sleeps 20 seconds, starts a new slave, sleeps 20 seconds, kills the
> master, etc.
> Also attached is a small java test program (MasterSlaveTest.java) The
> program starts 10 JMS senders that send 75kb text messages every 25 ms to
> unique queues. These messages contain a sequence number header (a long).
> The program also starts 10 receivers (1 for each queue) that keep track of
> the next expected sequence number and validate each incoming sequence number.
> If a receiver gets an unexpected sequence number, the test program exits
> (System.exit(1)). Both the senders and receivers use the failover transport
> to connect to the broker. Messages being sent are persistent, so in theory
> there should be no message loss when the master fails and slave takes over.
> I run the script to start the brokers, then run my test program. Most times
> when the script kills the master and the slave is promoted, things work fine
> - the test program reconnects, and messages continue to be delivered in
> order. If I run this long enough though, eventually my test program fails
> just after a slave broker is promoted to master with output similar to this:
> Mar 6, 2009 11:58:12 AM
> org.apache.activemq.transport.failover.FailoverTransport doReconnect
> INFO: Successfully reconnected to tcp://localhost:61616
> Mar 6, 2009 11:58:12 AM org.aaron.MasterSlaveTest$Receiver onMessage
> WARNING: test.queue.3 received 630 expected 629
> This indicates the receiver for test.queue.3 received message 630 after the
> slave broker took over and missed message 629.
> This seems to happen more often when more senders and receivers are running
> and more queues are in use. If I run a single sender/receiver pair on 1
> queue, it is very difficult to make this happen.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
