That's a little bit off-topic, but would you consider exchanging -Xmx into
-XX:MaxRAMPercentage for default configuration in 3.0 too? This would
universally improve default JVM memory settings under various scenarios,
without the need to change it every time more physical memory is added. And if
yes, should I create a ticket for this?
--
Vilius
-----Original Message-----
From: Clebert Suconic <[email protected]>
Sent: Thursday, January 15, 2026 12:36 AM
To: [email protected]
Subject: Re: K8s broker pod getting killed with OOM
so, in summary, what I'm recommending you is:
use max-size-messages for all the queues.. for your large queues, use something
like 10MB and for your small queues 100K
also keep max-read-page-bytes in use... keep it at 20M
If I could change the past I would have a max-size on every address we deploy,
and having global-max-size for the upmost emergency case..
it's something I'm looking to change into artemis 3.0 or 4.0. (I can't change
that into a minor version, as it could break certain cases...
as some users that I know use heavy filtering and can't really rely on paging).
On Wed, Jan 14, 2026 at 5:31 PM Clebert Suconic <[email protected]>
wrote:
>
> I would recommend against trusting global-max-size. and use max-size
> for all the addresses.
>
> Also what is your reading attributes. I would recommending using the
> new prefetch values.
>
>
>
> And also what operator are you using? arkmq? your own?
>
> On Wed, Jan 14, 2026 at 7:44 AM Shiv Kumar Dixit
> <[email protected]> wrote:
> >
> > We are hosting Artemis broker in Kubernetes using operator-based solution.
> > We deploy the broker as statefulset with 2 or 4 replicas. We assign for
> > e.g. 6 GB for heap and 9 GB for pod, 1.2 GB (1/5 of max heap) for
> > global-max-size. All addresses normally use -1 for max-size-bytes but some
> > less frequently used queues are defined with 100KB for max-size-bytes to
> > allow early paging.
> >
> >
> >
> > We have following observations:
> >
> > 1. As the broker pod starts, broker container immediately occupies 6 GB for
> > max heap. It seems expected as both min and max heap are same.
> >
> > 2. Pod memory usage starts with 6+ GB and once we have pending messages,
> > good producers and consumers connect to broker, invalid SSL attempts
> > happen, broker GUI access happens etc. during normal broker operations -
> > pod memory usage keeps increasing and now reaches 9 GB.
> >
> > 3. Once the pod hits limit of 9 GB, K8s kills the pod with OOMKilling event
> > and restarts the pod. Here we don’t see broker container getting killed
> > with OOM rather pod is killed and restarted. It forces the broker to
> > restart.
> >
> > 4. We have configured artemis.profile to capture memory dump in case of OOM
> > of broker but it never happens. So, we are assuming broker process is not
> > going out of memory, but pod is going out of memory due to increased
> > non-heap usage.
> >
> > 5. Only way to recover here is to increase heap and pod memory limits from
> > 6 GB and 9 GB to higher values and wait for next re-occurrence.
> >
> >
> >
> > 1. Is there any way to analyse what is going wrong with non-heap native
> > memory usage?
> >
> > 2. If non-heap native memory is expected to increase to such extent due to
> > pending messages, SSL errors etc.?
> >
> > 3. Is there any param we can use to restrict the non-heap native memory
> > usage?
> >
> > 4. If netty which handles connection aspect of broker can create such
> > memory consumption and cause OOM of pod?
> >
> > 5. Can we have any monitoring param that can hint that pod is potentially
> > in danger of getting killed?
> >
> >
> >
> > Thanks
> >
> > Shiv
>
>
>
> --
> Clebert Suconic
--
Clebert Suconic
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