Does anyone run their own Lemmy instance on a pi? How was the process of setting it up? Were there any pitfalls? How is performance?
[Edit]
So a lot of testing around. Compiling from scratch, etc, etc...
So far i have tried
installing lemmy using rootless docker (on 0.17.3)
compiling the image 0.18 docker image as arm
rootless docker did not work well for me. lots of systemd issues and i gave up after running into a lot of issues.
I tried rootless docker for security reasons. minimal permissions, etc.
When trying to compile the latest lemmy image in arm, i ran into issues with muslrust not having an arm version. It might be worth investigating rewriting the docker file from 0.17.3 to work with 0.18.0 but i haven't investigated that fully yet!
I tried compiling the latest image because i wanted to be able to use the latest features
At the moment, I'm trying to set lemmy to run under bare metal. Im currently attempting to compile lemmy under arm. If that works, i'll start setting up .service files to start up lemmy and pictrs.
Are you asking me what i plan to set the cap to? I guess just me. I cant see anyone else wanting to run off a pi from my house and there are so many other instances to join.
I would also add that Lemmy is part of the fediverse, meaning it is federated. Federation means all instances "talk" to all instances (unless they defederate), so you aren't limited only to the content on one instance (or in some cases not even Lemmy, case in point: I'm posting this from my kbin.social account).
What happens to posts/comments and any media/content that is hosted on a server that just goes away (for example if I created one virtually and then deleted it or if a sdcard on a pi is corrupted)
If you upload an image to that server, the image will be gone. Your comments will still exist on other federated instances, assuming that instance was federated in the first place. But any replies to those communities will not propagate once the hosting instance is offline.
For example assume you have 3 instances, A, B, and C. You have an account on A and create a post to a community on A. At some point A goes away, but those posts and that community will still exist on B and C. So you create a new account on B, and reply to one of those posts... users on C won't be able to see those replies as A isn't there to broadcast those replies out. And if someone on C creates a new post on that community from A, you wouldn't be able to see it on B either.
P.S. The same is true if A just decides to defederate instead of shutting down. (other than the images and accounts would still exist obviously).
That, and somehow I think it's nice to be able to federate with a username within your own domain when you have one. (or multiple, decisions, decisions, which one to pick ;) )
Basically the limit would be the speed of the database and the drive it runs on. If you connect a SATA SSD via usb3 it shouldn't be too bad. Can't tell you exact figures but a few hundred users is probably ok if you don't expect the site to be super responsive.
My experience with databases in general (granted, more the big ones than stuff like Postgres and mySQL) is that a lot if not most of the stuff that's important for performance is held in memory (certainly they'll tend to keep the most frequently fetched stuff in memory, along with the most used indexes) so I suspect the bigger Pi devices (with 4GB and 8GB) might just have enough memory to handle a good number of people doing common usage stuff (say, checking All in Active mode).
With a really big database and usage profile which has a random uniform distribution (i.e. any data piece is just as likely to need to be fetched as any other) then for the DB to be I/O bound in a Pi makes sense, but it's my impression (or maybe its just me ;)) that Lemmy data access is very concentrated in a just a few things (which do change over time but the DB engine wll naturally adjust the memory cache contents for that kind of change)
From the little that I know about the structure of the Lemmy software, I expect it's the image server that'll have problems with slow I/O rather than the database.
Of course, all this is just conjecture, as while I worked in high performance computing, it wasn't exactly done with Raspberry Pi devices ;)
Thanks. Might be useful for there to be a table outling diffrent hardware configs and acceptable user loads as more people people consider creating instances.
its difficult because different users have different usage patterns.
for example, two users who never post and are never online at the same time really take no resources from each other. they are effectively "one" user.
one user who posts 10gb of content a day, and is constantly posting would be equivalent to hundreds of "normal" users.