Looks like it works.
Edit still see some performance issues. Needs more troubleshooting
Update: Registrations re-opened We encountered a bug where people could not log in, see https://github.com/LemmyNet/lemmy/issues/3422#issuecomment-1616112264 . As a workaround we opened registrations.
Thanks
First of all, I would like to thank the Lemmy.world team and the 2 admins of other servers @stanford@discuss.as200950.com and @sunaurus@lemm.ee for their help! We did some thorough troubleshooting to get this working!
The upgrade
The upgrade itself isn't too hard. Create a backup, and then change the image names in the docker-compose.yml and restart.
But, like the first 2 tries, after a few minutes the site started getting slow until it stopped responding. Then the troubleshooting started.
The solutions
What I had noticed previously, is that the lemmy container could reach around 1500% CPU usage, above that the site got slow. Which is weird, because the server has 64 threads, so 6400% should be the max. So we tried what @sunaurus@lemm.ee had suggested before: we created extra lemmy containers to spread the load. (And extra lemmy-ui containers). And used nginx to load balance between them.
Et voilร . That seems to work.
Also, as suggested by him, we start the lemmy containers with the scheduler disabled, and have 1 extra lemmy running with the scheduler enabled, unused for other stuff.
There will be room for improvement, and probably new bugs, but we're very happy lemmy.world is now at 0.18.1-rc. This fixes a lot of bugs.