Creating a consumer only to consume 1 message is not ideal - there's a lot
of overhead and work on the broker side when consumers are created.
With that said, since the consumer should be getting closed properly, that
should not cause a leak.
So first, I would prioritize the version update. Second, I would consider
changing the use of consumers so they are longer-lived - preferrably only
being removed once the application needs to stop consuming.
If there is a need to throttle and/or control threading and parallel
processing of messages, perhaps Camel would be a good fit.
Hope this helps.
Art
On Wed, Aug 9, 2023 at 10:44 PM Jan Šmucr <jan.sm...@aimtecglobal.com>
wrote:
> Hello all. Thank you for your insights.
>
>
> * I’m using the core Java library.
>
>
> * Consumers are being created once per poll but reused if there are
> multiple inbound files to deal with. I create consumers like
>
> try (final consumer = createConsumer(session, params)) {
>
> // ...
> }
>
> so I expect them to be closed automatically.
>
>
> * I don’t use JMS, but the core sessions are used one per thread. The
> number of sessions opened and reported by Artemis doesn’t change over time.
>
>
> * I cannot reproduce the issue yet. It’s a production cluster, so
> today I’m going to set up my own playground.
>
>
> Jan
>
> From: Justin Bertram<mailto:jbert...@apache.org>
> Sent: středa 9. srpna 2023 17:41
> To: users@activemq.apache.org<mailto:users@activemq.apache.org>
> Subject: Re: Hunting memory leaks
>
> I echo Tim's recommendation to use the latest release, but I don't mean to
> say that will certainly resolve the problem.
>
> I can't say if you're doing anything wrong without more information. Can
> you answer the following questions?
>
> - What client library are you using?
> - How often are consumers being created?
> - Are consumers being closed properly once they are no longer needed?
> - Are JMS sessions being used concurrently from multiple threads?
> - Do you have a way to reproduce this that you can provide to me? A
> reproducer would make diagnosing this issue much simpler.
>
> Entries to the list of filter strings are added when a consumer is created
> and removed when a consumer is closed so at first glance it appears you're
> leaking consumers.
>
>
> Justin
>
> On Wed, Aug 9, 2023 at 7:07 AM Jan Šmucr <jan.sm...@aimtecglobal.com>
> wrote:
>
> > Hello.
> > I’m using a simple master-slave Artemis 2.26.0 cluster, and I’m noticing
> > heap usage growing more and more each day no matter the throughput.
> There’s
> > about 670 sessions at the same time opened for producers and consumers.
> > Consumers are polling queues on regular basis, some once a second
> (meaning
> > 1s timeout), some less often. This is by design and cannot be altered.
> All
> > client resources are being reused as much as possible. Usually there’s a
> > thread pool and the threads have a session opened, and wait for tasks to
> be
> > available to them.
> > It appears to me that the more consumers there is the faster the server
> > heap depletes.
> > Now, I’m not very familiar with leak hunting apps, so all I have are tiny
> > hints that it may have something to do with filter strings not being
> reused
> > and/or thrown away when not needed any more. I don’t know if I can post a
> > screenshot here so I uploaded it here: https://snipboard.io/LHifUK.jpg
> > This is from a heap dump opened in JMC JOverflow plugin.
> > Is there something obvious that I’m doing wrong? Do you have any clues on
> > what is going on here?
> > Thank you.
> > Jan.
> >
> >
>
>
