activemq-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Rob Davies (JIRA)" <j...@apache.org>
Subject [jira] Resolved: (AMQ-2413) Hangs possible because of Queue.doPageIn
Date Fri, 25 Sep 2009 08:35:52 GMT

     [ https://issues.apache.org/activemq/browse/AMQ-2413?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Rob Davies resolved AMQ-2413.
-----------------------------

       Resolution: Fixed
    Fix Version/s: 5.3.0

Patch looks good to me - applied in SVN 818762

> Hangs possible because of Queue.doPageIn
> ----------------------------------------
>
>                 Key: AMQ-2413
>                 URL: https://issues.apache.org/activemq/browse/AMQ-2413
>             Project: ActiveMQ
>          Issue Type: Bug
>          Components: Broker
>    Affects Versions: 5.4.0
>         Environment: 5.4 branch 818147. Some changes after this hide this error, but
I'm still concerned it might be a problem.
>            Reporter: Colin MacNaughton
>            Assignee: Rob Davies
>            Priority: Critical
>             Fix For: 5.3.0
>
>         Attachments: AMQ-2413patch.txt
>
>
> I don't understand the intent of the following code in Queue.doPageIn() and in rev 818147
it was causing delivery to the consumer to get hung (temporarily until message expiration
check kickstarts it again). See the commented out lines of code that determine how many messages
to attempt to page in. 
> {code}
>     private List<QueueMessageReference> doPageIn(boolean force) throws Exception
{
>         List<QueueMessageReference> result = null;
>         List<QueueMessageReference> resultList = null;
>         synchronized(dispatchMutex) {
>             //WHAT IS THIS DOING?
>             //int toPageIn = getMaxPageSize() + Math.max(0, (int)destinationStatistics.getInflight().getCount())
-pagedInMessages.size();
>             //DOES THIS MAKE MORE SENSE:
>             int toPageIn = Math.min(getMaxPageSize(), messages.size());
>             
>             if (LOG.isDebugEnabled()) {
>                 LOG.debug(destination.getPhysicalName() + " toPageIn: "  + toPageIn +
", Inflight: "
>                         + destinationStatistics.getInflight().getCount()
>                         + ", pagedInMessages.size " + pagedInMessages.size());
>             }
>             
>             //WHAT IS THIS DOING?
>             //toPageIn = Math.max(0, Math.min(toPageIn, getMaxPageSize()));
>                        
>             if (isLazyDispatch()&& !force) {
>                 // Only page in the minimum number of messages which can be dispatched
immediately.
>                 toPageIn = Math.min(getConsumerMessageCountBeforeFull(), toPageIn);
>             }
>    
> {code}
> It is definitely possible that I'm just not understanding the intent of the code, but
whatever it is, it's not working, and consequently I'm not sure that the subsequent fixes
on the branch have eliminated the problem. The attached patch contains both a unit test, that
tests several combinations of ack mode, vm cursoring, and delivery mode, as well as version
of Queue which should be applied against revirion 818147 -- this version has the fix commented
out and preserves the buggy behavior

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message