Limit service memory usage

Installing and Using OpenWrt
1

Hi,

I would like to limit Adguard Home in its memory usage as it caused an unexpected router reboot when it updated dns filter lists a number of times due to OOM conditions.

in its init script I set procd_set_param limits rss="131072 131072" to hopefully limit memory usage to 128 MiB. the thing is, router (when not running adguard instance) constantly has more free memory that that limit, so if that limit worked it should prevent any further crashes. Yet it doesn't.

So here is my question, how to properly limit memory/cpu usage of a service? I noticed that each running service has its own cgroup defined under /sys/fs/cgroup/services/<service name>, yet there is memory.max_bytes nor anything related to memory whatsoever. Is it dependent on hardware perchance?

2

Good hoping, it will dump client traces in /tmp until full.

3

Is it unavoidable? Does openwrt even collect core dumps by default?

4

agh does, does not seem there is any limit on storage of those.

5

Isn't AdBlock going to crash when it fails to allocate all the memory it needs?

1 Like
6

Adguard Home is rather bloated, depending on your needs you can use an Adblock package and e.g. https-dns proxy for secure DNS, that is what is working for me at least :).

1 Like
7

In practical terms, is there really much of a difference between 'just' the DNS server crashing - or the whole router?

2 Likes
8

The unfortunate consequence, which is preferable to crashing the whole router. But with proper service management crashed services should just come right back up, am I right?

I used adblock-lean in the past but the webUI of adguard is hard to pass for me.

In my book the less fatal crashes there are the better but what do I know.
Also rebooting takes more time, breaks ssh sessions and puts (minimal) albeit non-zero stress on hardware and firmware which may or may not be so keen on booting up again after unscheduled abrupt shutdown.
Also again, with local DNS caching I can get by without DNS for a bit and local networking still works, and those 2 seconds when AGH reboots shall not pose a great problem.

Back to the point: how can I limit system resources per service?

9

Sorry, but I do not see the point... If a service, under normal circumstances, uses too much memory, what is the point? You make it crash, it restarts, then back to using too much memory...

10

It crashes onlsdy in certain conditions, adguard home is memory hungry on filter updates, sometimes to the point of crashing the whole thing.
It starts with filters disabled so there is no chance of it just crashing in a loop.

11

Update as in fetching updated lists ?

Disable auto update, and restart the service every day to force an "update"?