Install atop, basically 'top' on steroids with history.. It defaults to capturing performance data every 5 minutes, I usually change it to 1 minute on production systems.
this post was submitted on 10 May 2024
26 points (88.2% liked)
Selfhosted
39964 readers
294 users here now
A place to share alternatives to popular online services that can be self-hosted without giving up privacy or locking you into a service you don't control.
Rules:
-
Be civil: we're here to support and learn from one another. Insults won't be tolerated. Flame wars are frowned upon.
-
No spam posting.
-
Posts have to be centered around self-hosting. There are other communities for discussing hardware or home computing. If it's not obvious why your post topic revolves around selfhosting, please include details to make it clear.
-
Don't duplicate the full text of your blog or github here. Just post the link for folks to click.
-
Submission headline should match the article title (don’t cherry-pick information from the title to fit your agenda).
-
No trolling.
Resources:
- selfh.st Newsletter and index of selfhosted software and apps
- awesome-selfhosted software
- awesome-sysadmin resources
- Self-Hosted Podcast from Jupiter Broadcasting
Any issues on the community? Report it using the report flag.
Questions? DM the mods!
founded 1 year ago
MODERATORS
If you’re seeing an OOM killer messsage note that it doesn’t necessarily kill the problem process, by default the kernel hands out memory upon requestt, regardless of whether it has ram to back the allocation. When a process then writes to the memory (at some later time) and the kernel determines that there is no physical ram to store that write, it then invokes OOM Killer. This then selects a process and kills it. MySQL (and MariaDB) use large quantities of ram for cache, and by default the kernel lies about how much is available, so they often end up using more than the system can handle.
If you have many databases in containers, set memory limits for those containers, that should make all the databases play nicer together. Additionally , you may want to disable overcommit in the kernel, this will cause the kernel to return out of memory to a process attempting to allocate ram and stop lying about free ram to processes that ask, often greatly increasing stability.
If you saw an OOM anything, it's getting OOMkill'd by the kernel trying to keep the machine up. Check syslogs and dmesg, and it should say what was killed, and there's your problem container. You probably have a memory leak, so just check your container stats every so often and see what is growing out of control with memory usage.
Enable swap regardless. Would also help to know what you're running.
Are you running them from your user session? If so, when you log out it will stop your processes, unless you have enabled 'linger' mode.
I would start all containers except one. If everything works that one is the cause of the problem. Keep trying with a different container every time.
The issue with diagnosing memory issues is that it usually results in no memory available to handle the logging of such a problem when it happens.
I've found that the easieat approach is to set up a file as additional swap space, and swapon, then see if the problem disappears, either partially or fully.
When I had the issue with mariadb demon been killed, I think either in dmesg or syslog there was an entry reading "Out of memory: Kill process... " or similar.
I'll have a look, thx