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Elixir saves Pinterest $2M a year in server costs

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Re: Elixir saves Pinterest $2M a year in server costs

#231

Post by pdimitar »

wild_egg wrote: post #209
pdimitar wrote: post #196

Earlier quoted context omitted.

There is a reason: the BEAM is almost not prone to huge GC pauses. Bigger load results in every actor responding very slightly slower. Nothing else. Many other systems don't have this property. They fall down under pressure. Gosh, a huge chunk of HN is always so dismissive. At least read up a bit beforehand, man. The criticisms should be informed and benefit the readers, not only express a generic skepticism.

If you're seeing GC pauses of >1ms in Go, please report a bug

Golang is actually my #2 after Elixir (simply because Elixir code is much more terse and often more readable).

So yeah, Golang's GC is world-class, no argument from me.

Re: Elixir saves Pinterest $2M a year in server costs

#232

Post by pdimitar »

fidotron wrote: post #229
pdimitar wrote: post #228

Earlier quoted context omitted.

I can see how you would think that, yes. In practice I haven't noticed it except in super rare cases where processes (actors) hold on to huge binaries / strings -- which is one of the weak points of BEAM's GC.

My experience of this is not theoretical.

Maybe you should write a blog post about it, many in the Elixir's ecosystem are very serious devs and are always looking at ways to improve it.

Re: Elixir saves Pinterest $2M a year in server costs

#233

Post by throwaway894345 »

pdimitar wrote: post #225
SanderNL wrote: post #205

Earlier quoted context omitted.

That does not in any way explain a drop of 95%, which IMO is ridiculous and points to other issues. The system they created now is totally different from the one they had. It’s more efficient by an insane margin. Choice of language seems like it would have trouble breaking the top 5 major reasons.

Why is it ridiculous? I migrated Rails apps to Elixir before, we reduced from 15 servers to 3, and 1 was basically "if crap hits the fan", we could have gotten away with 2 easily. It's worrying that a supposedly high-quality forum like HN receives comments with no substance. If you have an actual counter-argument, let's discuss. If not, well, not an interesting exchange.

You’re comparing Elixir to Python and Rails. Many of us have seen Python replaced with other languages for an astronomical improvement. Python and Ruby are the slowest category of languages; they’re easily beaten and you need to offer some evidence as to why the improvement was derived from migrating to Elixir specifically rather than moving away from Python/Rails.

Re: Elixir saves Pinterest $2M a year in server costs

#234

Post by pdimitar »

throwaway894345 wrote: post #221
pdimitar wrote: post #196

Earlier quoted context omitted.

There is a reason: the BEAM is almost not prone to huge GC pauses. Bigger load results in every actor responding very slightly slower. Nothing else. Many other systems don't have this property. They fall down under pressure. Gosh, a huge chunk of HN is always so dismissive. At least read up a bit beforehand, man. The criticisms should be informed and benefit the readers, not only express a generic skepticism.

Go also doesn’t have huge GC pauses (and moreover idiomatic Go generates very little garbage)and I have a hard time seeing how GC pauses would contribute so significantly. Java also allegedly has a very low latency collector.

Apologies, I was only responding to a single point which was meant to counter another. I am well aware that Golang's GC is world-class and it's my second most loved language after Elixir.

Re: Elixir saves Pinterest $2M a year in server costs

#236

Post by malodyets »

_m8fo wrote: post #109
mcintyre1994 wrote: post #106

Earlier quoted context omitted.

I think Node is still single core by default? Elixir (or rather the Beam) will handle core utilisation so if you start a load of Elixir processes they’ll be spread across multiple cores.

[flagged]

I wish you wouldn’t delete your posts - it makes it hard to understand what the following comments are responding to.

Re: Elixir saves Pinterest $2M a year in server costs

#237

Post by pdimitar »

throwaway894345 wrote: post #233
pdimitar wrote: post #225

Earlier quoted context omitted.

Why is it ridiculous? I migrated Rails apps to Elixir before, we reduced from 15 servers to 3, and 1 was basically "if crap hits the fan", we could have gotten away with 2 easily. It's worrying that a supposedly high-quality forum like HN receives comments with no substance. If you have an actual counter-argument, let's discuss. If not, well, not an interesting exchange.

You’re comparing Elixir to Python and Rails. Many of us have seen Python replaced with other languages for an astronomical improvement. Python and Ruby are the slowest category of languages; they’re easily beaten and you need to offer some evidence as to why the improvement was derived from migrating to Elixir specifically rather than moving away from Python/Rails.

Sure, not wrong on the outset, but you do come across as dismissive of Elixir while stating this.

Re: Elixir saves Pinterest $2M a year in server costs

#238

Post by zaphar »

Thaxll wrote: post #199
sph wrote: post #64

Earlier quoted context omitted.

The advantages of Elixir are not performance-related. There is a lot of focus on raw performance on web-related services, when in reality most of their running time is spent waiting for IO. If there are two things the BEAM excels at, is IO and turning almost any problem into half a dozen processes that are scheduled and run in parallel, if not geographically-distributed, with 1/50th the effort of any other language.…

I wrote the same kind of tool in both Elixir and Go, the performance difference was huge between the two, Elixir / Erlang is pretty slow overall.

The go runtime has similar capabilities as the BEAM runtime when it comes to concurrent workloads. Go has the benefit of being a typesafe compiled language which gives it speed benefits. But using either one of them instead of Java is probably going to be a huge win for most teams on concurrent workloads.

Re: Elixir saves Pinterest $2M a year in server costs

#239

Post by zaphar »

Thaxll wrote: post #201
sph wrote: post #64

Earlier quoted context omitted.

The advantages of Elixir are not performance-related. There is a lot of focus on raw performance on web-related services, when in reality most of their running time is spent waiting for IO. If there are two things the BEAM excels at, is IO and turning almost any problem into half a dozen processes that are scheduled and run in parallel, if not geographically-distributed, with 1/50th the effort of any other language.…

Elixir does not do anything better at IO than other languages.

They do have a really compelling conccurent processing story though, which is what most people mean when they say it's better at IO.

Re: Elixir saves Pinterest $2M a year in server costs

#240

Post by arrowsmith »

skrebbel wrote: post #218
arrowsmith wrote: post #203

Earlier quoted context omitted.

As much as I love Elixir, it's really not just "basically Ruby with some slight modifications". The syntax is similar at a glance, but there are some major design differences (e.g. immutability); solving the same problem in Elixir and Ruby can require a completely different structure to your code. I wrote this blog post about what I think are the three most important differences between Elixir and Ruby: https://phoen…

No monads though. No pure functions, no Option types, pretty much no recursion in practice. Really it’s got none of the stuff that makes some FP languages hard to learn. (Except maybe “no for loops”).

That's true - Elixir is simpler to learn than, say, Haskell. All I'm saying is that it's not a trivial jump from Elixir to Ruby, despite the superficially similar syntax.
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