# Unusually high CPU usage

**URL:** https://meta.discourse.org/t/unusually-high-cpu-usage/394651
**Category:** Self-hosting
**Created:** [January 29, 2026, 1:27pm UTC](https://meta.discourse.org/t/unusually-high-cpu-usage/394651 "2026-01-29T13:27:05Z")
**Posts on this page:** 1
**Showing post:** 7

<div class="post-metadata">

### Author: ![supermathie](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/supermathie/32/507518_2.png) [@supermathie](https://meta.discourse.org/u/supermathie)
#### Post date: [January 29, 2026, 9:48pm UTC](https://meta.discourse.org/t/unusually-high-cpu-usage/394651/7 "2026-01-29T21:48:01Z")

</div>

> [@char](#):
>
> This is definitely a memory issue: I’m seeing some huge queries here.

> [@pfaffman](#):
>
> It looks like there are a bunch of idle postgres processes eating a bunch of memory, I think.

This doesn’t look like a memory problem to me - there’s only around 6GB taken up by applications. There’s a lot of _reading_ happening, which at a guess I’d say (along with sidekiq being busy) maybe postgres is doing a lot of reading of old data from disk, maybe to do some stats jobs. If the database doesn’t fit in RAM, it’s potentially going to do a lot of reading if that older data is being accessed. That’s what this smells like.

```plaintext
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
admin 2510013 15.8 1.6 7383364 514764 ? SNl 12:55 56:45 sidekiq 7.3.9 discourse [3 of 5 busy]
systemd+ 2848301 26.9 25.3 8058104 7806820 ? Rs 17:45 18:18 postgres: 13/main: discourse discourse [local] SELECT
systemd+ 2870880 4.3 22.9 8058516 7072000 ? Ds 18:03 2:09 postgres: 13/main: discourse discourse [local] SELECT
systemd+ 2875058 21.0 25.4 8101952 7848140 ? Rs 18:07 9:46 postgres: 13/main: discourse discourse [local] UPDATE
systemd+ 2924006 30.2 25.3 8112844 7824292 ? Rs 18:44 2:44 postgres: 13/main: discourse discourse [local] UPDATE
jystemd+ 2929546 12.8 24.9 8049520 7694404 ? Ss 18:48 0:39 postgres: 13/main: discourse discourse [local] SELECT
systemd+ 2931802 17.7 24.5 8045744 7559492 ? Ss 18:50 0:36 postgres: 13/main: parallel worker for PID 946796
systemd+ 2931803 17.7 24.5 8045744 7557568 ? Ds 18:50 0:36 postgres: 13/main: parallel worker for PID 946796

```

I would look at sidekiq first - I bet it’s busy running updates. Check the `/sidekiq` url while logged in as admin to see what it’s doing. That’s probably going to show you some long-running update tasks.

You can also, on the SQL server:

```plaintext
SELECT pid, application_name, query
FROM pg_stat_activity
WHERE state IS NOT NULL
  AND state != 'idle';

```

to see what queries are running and what’s calling them. That’ll hint towards what’s causing the load.

Do you have [performance headers enabled](https://meta.discourse.org/t/how-to-scale-further-2-mm-posts-80k-per-month/216082/19)? You can turn those on and capture them in logs to let you know how much time Discourse is spending on each part.

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