Another day, another update.

More troubleshooting was done today. What did we do:

  • Yesterday evening @phiresky@[email protected] did some SQL troubleshooting with some of the lemmy.world admins. After that, phiresky submitted some PRs to github.
  • @[email protected] 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 404 in 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=5 in 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 @[email protected] , @[email protected] , @[email protected], @[email protected] , @[email protected] , @[email protected] for their help!

And not to forget, thanks to @[email protected] and @[email protected] 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.

  • _Rho_
    link
    46
    edit-2
    1 year ago

    As a data engineer, I’d be interested in hearing more about the SQL troubleshooting.

    EDIT: It looks like [email protected] is a good place to subscribe to for more technical info on some of these performance improvements.

    Also the Lemmy GitHub of course contains more information on bugs/enhancements/etc.

    • @tsz
      link
      51 year ago

      Yes please

    • @Schmedes
      link
      41 year ago

      Same, my job is like 80% SQL, so it’d be cool to see what is used in the background and maybe help improve things.

    • @DeputyRan
      link
      11 year ago

      Same here! If you find a way to contribute please give us an update!

      • _Rho_
        link
        11 year ago

        Just edited my comment!