As always, lists like these don’t include Joe Armstrong's PhD thesis “Making reliable distributed systems in the presence of software errors” - http://erlang.org/download/armstrong_thesis_2003.pdf
I would be concerned as an examiner if this came across my desk, more so if I read the colophon where the author comments that they intended to write their own typesetting system, before reading Knuth and wisely concluding that they were unlikely to do anything better than TeX. Top tier yak shaving there.
Just the first 2 chapters (~30p) + the Conclusion (~10p) contain a lot of useful food for thought.
Erlang is simply the right language to build a chat server with, and it doesn't make sense to rewrite it in another language, even though Facebook did that with the server for Messenger. :P
Certainly parts of the WhatsApp stack have changed considerably. No more FreeBSD / no more only a handful of OS processes per node, much less Mnesia (not sure if there's any Mnesia left... I don't get that level of information). I've seen signs that they may have returned to large nodes, so they might be back to millions of connections per node, but that was very much not the case when I left; connection counts had dropped on our FreeBSD nodes because we were doing a lot more on the chat channel and then again because the Facebook nodes we migrated to were so much smaller than our FreeBSD nodes.
The problem is finding talent that knows both distributed systems, and Erlang/Elixir. But Erlang/OTP can replace a lot of expensive kludges. =3
If you can convince your employer of that. I'm working on a system today (and not for the first time) that could have significantly reduced complexity by switching to Erlang (or Elixir) and OTP. Amusingly, it's a glorified, in-house telecom system that was developed because they chose not to buy an existing solution.
Notably, it is possible to rebuild or move the entire infrastructure by issuing a signed resend-logs-to-new-consumer request to clients or servers.
If you start with a dumpster fire at a dried fish factory, than 3 week solutions that last 6+ years under load look pretty nice in retrospect. Your boss is probably contemplating why most Erlang/Elixir people don't work for clown wages. =3
> If you can convince your employer of that.
It's probably easier to find an employer that's already convinced. But that's not easy either. :P I'm working in Rust now, because that's what the employer wants to do and it works enough. Half of my work problems would evaporate if we switched to BEAM, but I'd still have the other half and new ones and I'm not sure the rest of the team would be as excited as I am. And they almost certainly wouldn't let me hot load code, which means less fun and less fast iteration :(
Convincing an employer to switch languages is generally hard, regardless of which language, but switching to a system built on BEAM is probably a bigger change than most.
Scala is kind of a more modern alternative.
If doing a twitter like platform, elixir with Phoenix channels could handle around >20k users per host. Very few other options work for that use case. =3
https://blog.stenmans.org/theBeamBook/#_concurrency_parallel...
In distributed systems the fist lesson is resilience is more important.
Spend enough time in a computer lab, and you will see things halt and catch fire on occasion. Especially if it has a bunch of GPUs pinning the utilization 24/7, or a cheap power supply in the cluster. =3
Per-lecture reading lists are on the course page [1]. He also points at Elaine Shi's Foundations of Distributed Consensus and Blockchains [2] and Andrew Lewis-Pye's Consensus in 50 pages [2] as background, though these are more textbooks, not papers.
Remarkably, the first 7 lectures deal with permissioned systems, recapitulating the classic results of consensus in distributed systems (Dolev Strong, FLP impossibility, CAP) - no blockchain in sight. This takes us to the state of the art at the end of the 1990's (with algorithms that can achieve consensus in the presence of byzantine failures, namely Byzantine Paxos and PBFT, though he discusses a modern variant, permissioned Tendermint from 2014).
Lecture 8 stays permissioned and proves consistency and chain quality for the longest-chain rule. Only at Lecture 9, with proof of work, does anything specifically blockchain appear; then L10 block rewards and selfish mining, L11 transaction fee mechanism design; L12 proof-of-stake sybil resistance with the whole litany of attacks possible there.
Very good series in my view, and shows how little technical merit this whole blockchain circus has - nearly all the great properties people tout (reliability, consistency, audibility, availability) can be achieved with good old permissioned tech more efficiently, with pretty instant and deterministic finality.
Anyway, I found the series worth watching for the classical consensus material alone.
[0] https://www.youtube.com/playlist?list=PLEGCF-WLh2RLOHv_xUGLq...
[1] https://timroughgarden.github.io/fob21/