mjolnir VS Synapse

Ah, for a moment, I thought this was about the [Mjölnir project](https://github.com/matrix-org/mjolnir/) in Matrix-land.

I'm running a small (at the beginning it was completely public, now I'm keeping an eye on registrations) homeserver with synapse for a few years - I really like Matrix on a conceptual level and I'm happy that it exists even through it's not perfect it works pretty well mostly. I don't want to be too harsh because it's the best decentralized alternative for chat at the moment and it's open-source and there is a lot of progress but damn' it was a pain in the ass to run that server... we solved our problems mostly with throwing resources and memory on the problem... it's a nice tour de force if you want to learn about debugging distributed systems but it's nothing to install somewhere and just keep running.

synapse is quite a mess and there are a lot of hidden footguns if you just run a server - this is just the tip of iceberg to keep the postgres database somewhat sane: https://levans.fr/shrink-synapse-database.html - lot's of other issues in the issue-tracker where you can just scratch your head.

bridges are all subtly broken - the xmpp bridge is horrible and broke in so much interesting ways that I'm not going to touch it ever again - telegram works okay most of the time, irc-bridge also have some warts - but it's easy to criticize from my chair and probably unfair to talk so negative about it here but it's often buggy and broken for edge-cases - it works most of the time pretty okay but it's quite a mess and difficult to debug things.

moderation/spam/etc.pp is all hackable but it's all mostly quickly hacked up nodejs code that at least for us exploded in all kinds of interesting ways. https://github.com/matrix-org/mjolnir writing 3tb of logs in a few weeks and heating memory like crazy for instance. It's all complicated and there is no simple ui for anything.

So it's powerful but requires quite a bit of dedication and patience to get right. It's a full blown distributed system and often state is all over the place and once you make a mistake it's difficult to get right.

But there are so much promising projects that I'm confident that these issues will be resolved and it will only get better but in my experience it will break badly on all kinds of edge-cases - the mentioned xmpp-bridge created usernames that can't be deleted via the http api for instance. someone bridged 1000 channels via our telegram-bridge and there is no code to remove those channels - you have to code something up in python for yourself. irc bridge kicks you after 30 days idle because they can't handle the connections - freenode (before the takeover) said it's not them - maybe single threaded nodejs is not such a good idea for that.

Could I do it any better and delivering? Probably not. But except some adventure and if you want to deploy it for an org carefully test any assumptions you take for granted. It's cool but it's also kind of quick'n'dirty in a lot of ways. Still better than anything else I'd use it over any megacorp messenger anytime but maybe don't switch your family yet.

Moderation tools are slowly improving, but definitely still don't fit all use cases, and it's very unfortunate they don't come natively with synapse. I'm the lead admin of a Matrix ' Space', and our main room now has over 6,000 users (80%+ are inactive or barely active). We use mjolnir(https://github.com/matrix-org/mjolnir) to ban and redact users/servers/messages across all of our rooms, which has been a godsend since I used to have to redact all the racist/gore myself message-by-message. It's still reactive instead of proactive, but I'm hoping these tools will mature in time.

What are you thinking of here? Synapse has supported purging room history since 2016: https://github.com/matrix-org/synapse/pull/911, and configurable data retention since 2019: https://github.com/matrix-org/synapse/pull/5815.

Meanwhile, Matrix has never needed the full room history to be synchronised - when a server joins a room, it typically only grabs the last 20 messages. (It does needs to grab all the key-value state about the room, although these days that happens gradually in the background).

If you're wondering why Matrix implementations are often greedy on disk space, it's because they typically cache the key-value state aggressively (storing a snapshot of it for the room on a regular basis). However, that's just an implementation quirk; folks could absolutely come up with fancier datastructures to store it more efficiently; it's just not got to the top of anyone's todo list yet - things like performance and UX are considered much more important than disk usage right now.

some context re the Matrix isses, long history apparently: https://github.com/matrix-org/synapse/issues/14481#issuecomm...

Why not Matrix? Here's one reason: it has incredibly hard-to-debug edge cases, and plenty of bugs. One of my favourites is the one where people are kicked out of your room at random, which was reported a year ago[0]. It wasn't fixed, however, because the head of the Matrix foundation (Matthew) presumably didn't like the issue being posted on Twitter.

This is honestly really disappointing behaviour from a platform owner.

[0]: https://github.com/matrix-org/synapse/issues/14481

> That doesn't make this situation any less bad to the rest of the community.

How is the community suffering here? Let's say Element adds a bunch of baller stuff to their versions over the next few months and then closes the source. Can't the community just fork the last AGPL version? You might say, "well then no one can take the AGPL fork and make their own closed-source business", but do you want them to? Even if you do, they still can with the existing Apache-licensed version, just like Element is doing right now.

You're arguing that Element will lose a lot of contributions, but TFA points out that despite being super open, the vast majority of contributions are still made by Element employees (which seems to be true [0]). It's not the case that Element is looking to monetize the (small) contributions of others, it is the case that others are looking to monetize the (huge) contributions of Element.

And besides, aren't the MSCs the core of Matrix? It's already super possible to build your own compliant client and server.

The situation is that Element needs money to keep developing the ecosystem. It would be cool if there were a big network of donors and contributions, but there isn't. You're essentially saying, "that's fine, go out of business then, and the community will keep developing the ecosystem", but that's not happening now, and it can still happen anyway with the Apache-licensed versions, which again people can still contribute to.

[0]: https://github.com/matrix-org/synapse/graphs/contributors