I think there is (was?) an attempt to rewrite Mastodon into Rust but I haven't heard much about it.
A single user Mastodon instance takes an unreasonable amount of resources. I don't know if it's just because of Ruby (Gitlab has the same problem, so it might just be) or because everyone is wasting money on expensive servers, but an RSS feed on steroid shouldn't take this much RAM.
Mastodon itself is designed for "flagship scale" (given lead developers run mastodon.social and mastodon.online, two of the biggest instances and the most "dogfooding" two instances) so it bundles an entire cluster of services: background processors (sidekiq), caches (redis, I think?), database server (postgres), optional ElastiCache, and more. I don't know how much Ruby itself accounts for expensive overhead, but just running all of those other things on a single server vertically for a single user instance is a massive, expensive overhead. (It's clearly built for horizontal scale where your background services and caches and database servers may all be different clusters of VMs/servers over vertical stack efficiency when "scaled down" from the "natural" "mastodon.social scale" that Mastodon is most optimized for.)
It's an interesting optimization problem reminder that scaling factors are different for different needs and not everything scales cleanly to every use case. A single user instance should be able to use a much smaller vertical stack, but scaling down from a wide horizontal stack is not necessarily the best or cheapest place to start when building something like that.
(There are some interesting projects I've seen to build single user instances with much less overhead, shorter vertical stacks. I'm curious to see where those efforts go. In my own usage of Mastodon my "single user" instance gets the benefits of the horizontal scaling Mastodon was built for because my hosting provider does a bunch of work to make sure that they take advantage of that economy of scale to host many small instances for cheaper than trying to run small instances in one-off VMs.)
This is the same problem that plagued mail servers. It takes so many different components which all have their own configurations to optimize (and memory/cpu footprints) that it ends up being too complex for most people to actually run an instance.
I'm also completely positive that a Go or Rust version on a $5 VPS with an in-memory database model (RocksDB, LevelDB, BadgerDB, etc..) could easily handle hundreds of thousands of users and gigs of content each day. It seems like it would be easy to expand that to a multi-node key-value store like TiDB, CockroachDB, etc.. if you needed to grow beyond a single host.
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I think there is (was?) an attempt to rewrite Mastodon into Rust but I haven't heard much about it.
A single user Mastodon instance takes an unreasonable amount of resources. I don't know if it's just because of Ruby (Gitlab has the same problem, so it might just be) or because everyone is wasting money on expensive servers, but an RSS feed on steroid shouldn't take this much RAM.
Mastodon itself is designed for "flagship scale" (given lead developers run mastodon.social and mastodon.online, two of the biggest instances and the most "dogfooding" two instances) so it bundles an entire cluster of services: background processors (sidekiq), caches (redis, I think?), database server (postgres), optional ElastiCache, and more. I don't know how much Ruby itself accounts for expensive overhead, but just running all of those other things on a single server vertically for a single user instance is a massive, expensive overhead. (It's clearly built for horizontal scale where your background services and caches and database servers may all be different clusters of VMs/servers over vertical stack efficiency when "scaled down" from the "natural" "mastodon.social scale" that Mastodon is most optimized for.)
It's an interesting optimization problem reminder that scaling factors are different for different needs and not everything scales cleanly to every use case. A single user instance should be able to use a much smaller vertical stack, but scaling down from a wide horizontal stack is not necessarily the best or cheapest place to start when building something like that.
(There are some interesting projects I've seen to build single user instances with much less overhead, shorter vertical stacks. I'm curious to see where those efforts go. In my own usage of Mastodon my "single user" instance gets the benefits of the horizontal scaling Mastodon was built for because my hosting provider does a bunch of work to make sure that they take advantage of that economy of scale to host many small instances for cheaper than trying to run small instances in one-off VMs.)
This is the same problem that plagued mail servers. It takes so many different components which all have their own configurations to optimize (and memory/cpu footprints) that it ends up being too complex for most people to actually run an instance.
I'm also completely positive that a Go or Rust version on a $5 VPS with an in-memory database model (RocksDB, LevelDB, BadgerDB, etc..) could easily handle hundreds of thousands of users and gigs of content each day. It seems like it would be easy to expand that to a multi-node key-value store like TiDB, CockroachDB, etc.. if you needed to grow beyond a single host.
https://github.com/rustodon/rustodon#readme which has an awesome name but you're correct it appears that specific repo stalled out. I didn't check on the 41 forks of it