[Architecture] Hub-Spoke model for federation? · Issue #3245 · LemmyNet/lemmy
github.com
Question One of the biggest issues I am currently seeing with Lemmy, is federation. Either... Federation between instances having issues. Federation is backed up. Federation / Syncing is not scalin...

https://github.com/LemmyNet/lemmy/issues/3245

I posted far more details on the issue then I am putting here-

But, just to bring some math in- with the current full-mesh federation model, assuming 10,000 instances-

That will require nearly 50 million connections.

Each comment. Each vote. Each post, will have to be sent 50 million seperate times.

In the purposed hub-spoke model, We can reduce that by over 99%, so that each post/vote/comment/etc, only has to be sent 10,000 times (plus n*(n-1)/2 times, where n = number of hub servers).

The current full mesh architecture will not scale. I predict, exponential growth will continue to occur.

Let’s work on a solution to this problem together.

  • andscapeEnglish
    2·
    1 year ago

    I understand the logic, and you’re right to think about how improve Lemmy’s scalability. But I’m not sure if this is the way to go.

    If you build a dedicated federation proxy for an instance, you’ve really just slightly moved the problem. The federation proxy is going to have the same scalability issues, and if anything the total load goes up.

    If you build multi-instance hubs, you suddenly introduce a lot of new issues.

    • Security: I think Lemmy checks the source of an update to verify that it comes from the legitimate host. You would have to introduce some kind of signatures to verify that the activity originated from the legitimate host.
    • Privacy: now your users have to trust the hub owners with their data, not just the instance.
    • Motive: who would be running the hubs, and why? They would have to be even bigger that the instances, and there would be much less incentive to do it.
      • andscapeEnglish
        1·
        1 year ago

        Yeah what’s being described there is basically a P2P model. I still think it wouldn’t make a huge difference in the chattiness of the protocol. At best it would redistribute the load for outgoing federation messages, but not for incoming ones. An instance still has to receive each message individually, regardless of where they comes from.