There's still a lot of WhatsApp Erlang tooling being published, so I'm pretty sure it's mostly still Erlang. I think I still know a couple people who would share with me if it was rewritten, although I left in 2019.
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.
> But Erlang/OTP can replace a lot of expensive kludges.
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.
>> But Erlang/OTP can replace a lot of expensive kludges.
> 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.
Ah, I just recommended simple AMQP (packed BSON <128k messages) for RabbitMQ with client x509 cert GUID access as secure "middleware" to link all the legacy systems together. The addition of a strict sanitization producer/consumer process bound to each cpu core handles a sliding window idempotent operation handler. Or, people can corrupt their own data if they really try for a finite period, but the system eventually becomes consistent.
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
There's still a lot of WhatsApp Erlang tooling being published, so I'm pretty sure it's mostly still Erlang. I think I still know a couple people who would share with me if it was rewritten, although I left in 2019.
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.
I doubt they changed out Erlang/Elixir, as it is mature backbone infrastructure. It has run many telecoms for over 30 years without issue.
The problem is finding talent that knows both distributed systems, and Erlang/Elixir. But Erlang/OTP can replace a lot of expensive kludges. =3
> But Erlang/OTP can replace a lot of expensive kludges.
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.
>> But Erlang/OTP can replace a lot of expensive kludges.
> 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.
Ah, I just recommended simple AMQP (packed BSON <128k messages) for RabbitMQ with client x509 cert GUID access as secure "middleware" to link all the legacy systems together. The addition of a strict sanitization producer/consumer process bound to each cpu core handles a sliding window idempotent operation handler. Or, people can corrupt their own data if they really try for a finite period, but the system eventually becomes consistent.
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