How Discord Scaled Elixir to 5,000,000 Concurrent Users

**rlefevre** · May 18, 2019, 2:33pm

And some discussion on Hacker News about it (including some OTP 20.0 optimizations).

Their published libraries described in the blog post:

manifold: Fast batch message passing between nodes for Erlang/Elixir
ex_hash_ring: A fast consistent hash ring implementation in Elixir
fastglobal: Fast no copy globals for Elixir & Erlang
semaphore: Fast semaphore using ETS

At last the praised free book from Fred Hebert: Stuff Goes Bad: Erlang in Anger

**AstonJ** · July 11, 2017, 11:09pm

Nice

I’ve made some changes to our Showcase section and moved this there

**OvermindDL1** · July 11, 2017, 10:37pm

Oh now that is very cool, they made a lot of little micro-libraries (micro as in one-file) that are very useful and simple.

**tmbb** · July 11, 2017, 11:56pm

Recompiling code on the fly so that the datastructure is “constant” is impossibly cool xD best cache ever

**adrianrl** · May 17, 2019, 10:03pm

Using Rust to Scale Elixir for 11 Million Concurrent Users

Nowadays it seems like they use a faster implementation with NIFs, here’s the library: SortedSet

**sorentwo** · May 17, 2019, 11:15pm

Thanks for the link, that is really handy. I implemented a custom MapSet with Erlang 21+ features which is 25% faster than the native MapSet, I expect this can be an even bigger improvement.

**tmbb** · May 18, 2019, 1:46pm

You should submit a PR to Elixir then!

**sorentwo** · May 19, 2019, 2:26pm

Absolutely, I planned on submitting a PR after support for Erlang 20 was dropped. That will probably be quite a while though, so I’ll probably investigate conditional compilation instead.