Another day, another update.
More troubleshooting was done today. What did we do:
- Yesterday evening @phiresky@phiresky@lemmy.world did some SQL troubleshooting with some of the lemmy.world admins. After that, phiresky submitted some PRs to github.
- @cetra3@lemmy.ml created a docker image containing 3PR's: Disable retry queue, Get follower Inbox Fix, Admin Index Fix
- We started using this image, and saw a big drop in CPU usage and disk load.
- We saw thousands of errors per minute in the nginx log for old clients trying to access the websockets (which were removed in 0.18), so we added a
return 404in nginx conf for/api/v3/ws. - We updated lemmy-ui from RC7 to RC10 which fixed a lot, among which the issue with replying to DMs
- We found that the many 502-errors were caused by an issue in Lemmy/markdown-it.actix or whatever, causing nginx to temporarily mark an upstream to be dead. As a workaround we can either 1.) Only use 1 container or 2.) set ~~
proxy_next_upstream timeout;~~max_fails=5in nginx.
Currently we're running with 1 lemmy container, so the 502-errors are completely gone so far, and because of the fixes in the Lemmy code everything seems to be running smooth. If needed we could spin up a second lemmy container using the ~~proxy_next_upstream timeout;~~ max_fails=5 workaround but for now it seems to hold with 1.
Thanks to @phiresky@lemmy.world , @cetra3@lemmy.ml , @stanford@discuss.as200950.com, @db0@lemmy.dbzer0.com , @jelloeater85@lemmy.world , @TragicNotCute@lemmy.world for their help!
And not to forget, thanks to @nutomic@lemmy.ml and @dessalines@lemmy.ml for their continuing hard work on Lemmy!
And thank you all for your patience, we'll keep working on it!
Oh, and as bonus, an image (thanks Phiresky!) of the change in bandwidth after implementing the new Lemmy docker image with the PRs.
Edit So as soon as the US folks wake up (hi!) we seem to need the second Lemmy container for performance. So that's now started, and I noticed the proxy_next_upstream timeout setting didn't work (or I didn't set it properly) so I used max_fails=5 for each upstream, that does actually work.
Even though i'm not from this instance, this is such a nice way of keeping the users posted about changes. I wish more companies (I know this is not a company) went straight to the point, instead of using vague terms like "improved stability, fixed few issues with an update" when things are changed. I hope all instance owners follow this trend.
The owner of your instance has been a big help. You've also chosen a good instance!
@sunaurus@lemm.ee is awesome. He keep us aware of what's happening, planned maintenance hours, etc. His commits on making lemmy scale horizontally is what kept lemm.ee snappy even when we had a huge influx of users. I hope Lemmy as a whole continues this ethos of collaboration.
As an IT support person, I've learnt to dumb things down for management. They don't want to hear stuff like "Increased the SGA, changed the buffer size and added a function based index...etc". Sometimes I'll do a short and a long version something like "the issue was around memory settings which have been increased", plus the detailed info.