At the time of writing, Lemmyworld has the second highest number of active users (compared to all lemmy instances)

Also at the time of writing, Lemmyworld has >99% uptime.

By comparison, other lemmy instances with as many users as Lemmyworld keep going down.

What optimizations has Lemmyworld made to their hosting configuration that has made it more resilient than other instances’ hosting configurations?

See also Does Lemmy cache the frontpage by default (read-only)? on !lemmy_support@lemmy.ml

  • PriorProject@lemmy.world
    0·
    1 year ago

    I’m not an admin, but have followed the sizing discussions around the lemmyverse as closely as I can from my position of lacking first-hand knowledge:

    • lemmy.ml is the biggest instance by user count, but runs on incredibly modest 8-cpu hardware. Their cloud provider doesn’t provide any easy scale up options for them, so they can’t trivially restart on a bigger VM with their db and disk in place. I suspect this means that instance is going to suffer for a bit as they figure out what to do next.
    • lemmy.world on the other hand was running on a box at least twice as big as lemmy.ml at last count, and I believe they can go quite a bit bigger if they need to.
    • The lemmy.world admins also run mastodon.world and lived through the twitterpocalypse, seeing peak user registrations rates of 4k per hour. So this is not their first rodeo in terms of explosive growth, I’m sure that experience gives them some tricks up their sleeve.
    • The admin team is pretty clearly technically strong. If I recall correctly, ruud is a professional database admin. One of the spooky parts of Lemmy performance-wise is the db. If ruud or others on the admin team custom-tuned their pg setup based on their own analysis of how/why it’s slow, they may be getting more performance per CPU cycle than other instances running more stock configs or that are cargo-culting tweaks that aren’t optimal for their setup without understanding what makes them work.

    I’m surprised that sh.itjust.works isn’t growing faster. They also have a hefty hardware setup and seemingly the technical admins to handle big user counts. I wonder if it’s a branding problem, where lemmy.world sounds inviting and plausibly serious where sh.itjust.works sounds like clowntown even though it’s run by a capable and serious team.

    • Retro@lemmy.world
      2·
      1 year ago

      I originally signed up with sh.itjust.works, but I wanted to be on the instance with the majority of migrants.

      Also, it sounds dumb, but I think the sh.itjust.works domain is just kinda weird, technically has a “curse word” in it (not that I personally care), and they don’t support NSFW content (which isn’t just used for porn). So, it didn’t make sense to have that as my home instance. 🤷‍♂️

      Edit: Also, this is my first comment on here! Hello world! 👋

      • PriorProject@lemmy.world
        2·
        1 year ago

        Yeah, I get it. Naming optics aside, it seems an instance with a lot of headroom relative to others, with a capable team. Would be near the top of my word-of-mouth options in spite of the idiosyncratic name.

    • wheen@lemmy.world
      1·
      1 year ago

      Can none of this scale horizontally? Every mention of scaling has been just “throw a bigger computer at it”.

      We’re already running into issues with the bigger servers being unable to handle the load. Spinning up entirely new instances technically works, but is an awful user experience and seems like it could be exploited.

      • PriorProject@lemmy.world
        2·
        1 year ago

        It’s important to recall that last week the biggest lemmy server in the world ran on a 4-core VM. Anybody that says you can scale from this to reddit overnight with “horizontal scaling” is selling some snake oil. Scaling is hard work and there aren’t really any shortcuts. Lemmy is doing pretty well on the curve of how systems tend to handle major waves of adoption.

        But that’s not your question, you asked if Lemmy can horizontally scale. The answer is yes, but in a limited/finite way. The production docker-compose file that many lemmy installs are based on has 5 components. From the inside out, they are:

        • Postgres: The database, stores most of the data for the other components. Exposes a protocol to accept and return SQL queries and responses.
        • Lemmy: The application server, exposes websockets and http protocols for lemmy clients… also talks to the db.
        • Lemmy-ui: Talks to Lemmy over websockets (for now, they’re working to deprecate that soon) and does some fancy dynamic webpage construction.
        • Nginx: Acts as a web proxy. Does https encryption, compression over the wire, could potentially do some static asset caching of images but I didn’t see that configured in my skim of the config.
        • Pict-rs: Some kind of image-hosting server.

        So… first off… there’s 5 layers there that talk to each other over the docker network. So you can definitely use 5 computers to run a lemmy instance. That’s a non-zero amount of horizontal scaling. Of those layers, I’m told that lemmy and lemmy-ui are stateles and you can run an arbitrary number of them today. There are ways of scaling nginx using round-robin DNS and other load-balancing mechanisms. So 3 out of the 5 layers scale horizontally.

        Pict-rs does not. It can be backed by object storage like S3, and there are lots of object storage systems that scale horizontally. But pict-rs itself seems to still need to be a single instance. But still, that’s just one part of lemmy and you can throw it on a giant multicore box backed by scalable object storage. Should take you pretty far.

        Which leaves postgres. Right now I believe everyone is running a single postgres instance and scaling it bigger, which is common. But postgres has ways to scale across boxes as well. It supports “read-replicas”, where the “main” postgres copies data to the replicas and they serve reads so the leader can focus on handling just the writes. Lemmy doesn’t support this kind of advanced request routing today, but Postgres is ready when it can. In the far future, there’s also sharding writes across multiple leaders, which is complex and has its downsides but can scale writes quite a lot.

        All of which is to say… lemmy isn’t built on purely distributed primitives that can each scale horizontally to arbitrary numbers of machines. But there is quite a lot of opportunity to scale out in the current architecture. Why don’t people do it more? Because buying a bigger box is 10x-100x easier until it stops being possible, and we haven’t hit that point yet.

    • Master@lemmy.world
      21·
      1 year ago

      Can confirm… I didnt sign up for sh.itjust.works solely because of the name… I dont particularly want that attached to every post I make.

    • Pspspspspsps@lemmy.world
      1·
      1 year ago

      I wonder if it’s a branding problem, where lemmy.world sounds inviting and plausibly serious where sh.itjust.works sounds like clowntown

      That was my thought process when choosing an instance tbh. I’m not a tech person, I looked at the list and lemmy.world was the first ‘safest feeling’ instance that had open sign up. I saw sh.itjust.works and didn’t even check their sign up process, there was too many periods in the strange name and it just looks weird to me as someone not used to these things. Edit: spelling

      • s4if@lemmy.world
        2·
        1 year ago

        nah, I’m bit regretting not signing up on their instance. sh.itjust.works is a cool name and can be a brag point. lol. lemmy world is a bit too generalist, but I won’t migrate there as ruud (the admin of lemmyworld) is doing a good job managing the instance. I appreciate that. :)

      • Z______@lemmy.world
        0·
        1 year ago

        I definitely second the motion on it being a branding problem. Stuff like sh.itjust.works seem to me like something that dark basement tech nerds would come up with that is “edgy” and really only used by them and other people like them.

        I’m not really into the ironic “edgy” aesthetic and part of the struggle with this transition for me has been orienting myself in the space because I don’t want to commit to some “sketchy” edgelord URL

        • DarkwingDuck@sh.itjust.works
          1·
          1 year ago

          something that dark basement tech nerds would come up with that is “edgy” and really only used by them and other people like them.

          That’s exactly what it is and why I love it. The whole thing about this federated networking is that it doesn’t matter where you signed up.

    • WaffleFriends@lemmy.world
      1·
      1 year ago

      I had a very similar thought process when choosing my instance. lemmy.world seemed like it would be more open to new users than an instance named sh.itjust.works. Idk why that was my thought process but I’m here now

    • StrayPizza@lemmy.world
      1·
      1 year ago

      I hope lemmy.ml can upgrade at some point. A lot of the slowness I’m running into is trying to browse/discovery communities that happen to live on that instance.

    • Druidgrove@lemmy.world
      1·
      1 year ago

      I’m now going to start incorporating “Sounds like clowntown” into my everyday conversations - that’s funny!