Hi! I'm not expert about it - that said, I would recommend you to learn about vm.overcommit_memory parameter vm.oom-kill (both on sysctl.conf)... I've found an article that scratches the subject (the best reading is the kernel docs of course): https://gist.github.com/t27/ad5219a7cdb7bcb977deccbc48a480d5 I'll give you no recommendations other than learning about those parameters and use with caution (extreme caution), because this is really sensitive subject. I do use some of these parameters for heavy loaded PostgreSQL database servers - I believe the same logic applies. Dealing with kernel parameters is always something that you must be careful, and there are no "cake recipes".
Regards, ER -----Mensagem original----- De: David Bennion <dav...@gmx.com.INVALID> Enviada em: quarta-feira, 8 de janeiro de 2025 11:50 Para: users@activemq.apache.org Assunto: Re: avoiding oom-killer on Artemis OOM Killer happens when Linux determines it doesn't have enough memory to keep going, so in an act of self preservation it kills a large memory consuming process rather than crash. So in your case we can see from the OOM Killer log that in your case you had 2627224kB resident which I think is closer to 2.6GB. That leaves 1.4GB for the OS and all other applications. The follow up question is then: is there anything else running on the box other than your JVM? The total memory for all apps and the OS must fit within the 4GB max. So even small apps that use any memory can accumulate and cause Linux to perform OOM killer. Are you certain there is no memory leak in your JVM app? Does it take some time before you get OOM killed? A memory leak would certainly push your consumption on the OS to where garbage collection can't occur. Unfortunately, Linux will simply kill the app rather than ask Java to garbage collect. If there is no memory leak, I wonder if garbage collection settings could be modified to be more aggressive? Can the JVM app survive with less memory and still be performant? If you were to set the app to use 1.5 GB or 1GB what happens? Can you watch this problem occur on a console? If you run a "top" on that machine sorted by memory do you see other memory consumers? Are those expected? Regards, David On Jan 8, 2025, 12:31 AM, at 12:31 AM, "Vilius Šumskas" <vilius.sums...@rivile.lt> wrote: >Hi, > >I‘m trying to configure our Artemis cluster nodes in such a way that it >won‘t get oom-killed by Linux kernel, but instead paging would occur. >Most of the times it works, however after considerable periods of >paging sometimes we get: > >Jan 07 19:02:11 activemq-artemis-node-1 kernel: >oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allow >ed=0,global_oom,task_memcg=/system.slice/activemq.service,task=java,pid >=4086,uid=1001 Jan 07 19:02:11 activemq-artemis-node-1 kernel: Out of >memory: Killed process 4086 (java) total-vm:4939656kB, >anon-rss:2627224kB, file-rss:0kB, shmem-rss:0kB, UID:1001 >pgtables:5588kB oom_score_adj:0 > >Full oom-killer dump https://p.defau.lt/?HayAcFR8RRDrVZZAlav4IA > >Artemis nodes are using standard JVM options coming from official >distribution: -Xms512M -Xmx2G . They run in dedicated virtual hosts >which have 4GB assigned. Nothing else runs on those boxes. >global-max-size is not set so occupies 1G. > >Just wondering, how JVM heap sizes should be configured in relation to >available RAM? I found just this vague description >https://activemq.apache.org/components/artemis/documentation/latest/per >f-tuning.html#tuning-the-vm but nothing concrete. There is also a >question of JVM Direct Memory and other memory sectors which are not >controlled by heap settings. Does Artemis use those and what is >recommended ratios for them? > >-- > Best Regards, > > Vilius Šumskas > Rivile > IT manager --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@activemq.apache.org For additional commands, e-mail: users-h...@activemq.apache.org For further information, visit: https://activemq.apache.org/contact
