Which companies are using Erlang, and why? • Hacker News Board

Re: Which companies are using Erlang, and why?

#141

Post by samvher » Mon, Sep 30, 2019, 2:03 PM UTC

strmpnk wrote: post #110

samvher wrote: post #50

Earlier quoted context omitted.

To be fair though many Erlang programmers also avoid hot loading code. For the rest, nice summary.

I’d not consider relup and module loading the same feature. It is rare to see relup (though I have used it, it’s tricky to make work) but hot code loading of modules was something we used extensively both during development but also in production to test out patches for problems. It was super easy to use and never a big problem. Keep in mind that we rolled out the patch incrementally to one or two machines and then t…

Not sure if you're asking, but I'm not repeating someone else's rumor. I started the set-up I work with using hot loading (after all that is one of the things that attracts to Erlang) where I mean just reloading modules on the VM. Unfortunately I would get module order wrong from time to time or I would forget dependencies, and I've seen many badfun errors as well (I admit I used too many anonymous functions). With only 1 node doing the work (I haven't used Erlang on large clusters) that's a bit more risk and those problems have gone away completely since I switched to a strategy where the whole system just stops and starts.

Re: Which companies are using Erlang, and why?

#142

Post by sandGorgon » Mon, Sep 30, 2019, 2:13 PM UTC

ihuk wrote: post #84

We developed Online Charging System in Erlang that served couple million subscribers for close to three years. I found the whole experience fairly terrible. Erlang is nice enough language and I don't mind the syntax but it's also kinda cumbersome and verbose at times. For example, adding `true -> ok` to every if statement gets old fast. Similarly, Erlang/OPT is a nice platform but some parts are fairly bad. Looking a…

did you use Vert.x ? IMHO that has the closest cognitive match to Erlang.

it regularly tops performance benchmarks - https://www.techempower.com/benchmarks/#section=data-r18&hw=... and super simple heroku deployments - https://github.com/vert-x3/vertx-examples/tree/master/heroku...

Also Kotlin !! https://vertx.io/docs/vertx-core/kotlin/ (kotlin vertx on heroku: https://github.com/vert-x3/vertx-examples/tree/master/kotlin...)

Re: Which companies are using Erlang, and why?

#143

Post by atemerev » Mon, Sep 30, 2019, 2:19 PM UTC

cmrdporcupine wrote: post #130

atemerev wrote: post #93

Earlier quoted context omitted.

Yes, it is battle-tested, and the testing result was the big failure: memory-related issues and vulnerabilities alone caused billions of dollars of damage, and on their way to cause more. It is generally not a good idea at all to use C++ in network-facing applications.

Google disagrees with you.

The first maxim of software architecture: You Are Not Google.

(And even at Google most systems running C++ code are their core indexing and analytical systems, which are not directly related to their Internet-facing perimeter; there are some exceptions, of course).

Re: Which companies are using Erlang, and why?

#144

Post by samvher » Mon, Sep 30, 2019, 2:23 PM UTC

wildduck wrote: post #92

atupis wrote: post #15

I have never programmed Erlang but it feels like it is the currently only language that is some kind of secret weapon. It has similar aura than Lisp had before that with Erlang you can do stuff beyond "normal" languages.

My main interest in Erlang is mnesia. A relational/object hybrid data model that is suitable for telecommunications applications. A DBMS query language, Query List Comprehension (QLC) as an add-on library. Persistence. Tables can be coherently kept on disc and in the main memory. Replication. Tables can be replicated at several nodes. Atomic transactions. A series of table manipulation operations can be grouped into…

Yeah mnesia is extremely clever and very fun to learn. Also being able to store basically any term without having to do conversions is very useful.

I've found some practical aspects a bit painful though. It took me a while to figure out how to make backups, migrate schemas to different sets of nodes, that sort of thing. Also there are size limits on disk-based tables which are a bit limiting, and while you can use table fragmentation to get around that to some extent it doesn't seem straightforward to use (I haven't dared so far). I also don't like the way it deals with netsplits - when nodes reconnect it tends to require manual action to resolve.

Re: Which companies are using Erlang, and why?

#145

Post by ramchip » Mon, Sep 30, 2019, 2:23 PM UTC

bpicolo wrote: post #136

ramchip wrote: post #132

Earlier quoted context omitted.

It’s rare in production, but fantastic in development. Often I don’t even restart my Elixir app when switching between git branches, because the hot reload is enough.

How do you know when it isn't enough?

The website turns into a Phoenix error page telling you to restart the app because config has changed.

Re: Which companies are using Erlang, and why?

#146

Post by kitplummer » Mon, Sep 30, 2019, 2:29 PM UTC

derpherpsson wrote: post #134

kitplummer wrote: post #129

Fairly blind question: does Erlang|Elixir and BEAM make any sense in a pseudo-embedded, edge compute or IoT environment with constrained resources (CPU and memory), or even ARM architecture? Aside from the developer-side things, if AMQP were to the centralized communications hub (e.g. RabbitMQ) does using Nerves on devices make any performance benefit - meaning BEAM and app(s) there? The intent would be pre-process d…

They make the most sense if you want lots and lots of simultaneous clients. Plus it gives you a little bit of safety if you write crappy code. Typically not suited for embedded. (Assuming you mean embedded as in severely limited in resouces, and not "modern embedded" where you have lots and lots of unused system resources. If you mean the latter then anything goes.)

Yep, modern embedded (e.g. rPi and other Intel-based devices). I suppose there would be limited connections from each device, but many devices.

Re: Which companies are using Erlang, and why?

#147

Post by cmrdporcupine » Mon, Sep 30, 2019, 2:30 PM UTC

atemerev wrote: post #143

cmrdporcupine wrote: post #130

Earlier quoted context omitted.

Google disagrees with you.

The first maxim of software architecture: You Are Not Google. (And even at Google most systems running C++ code are their core indexing and analytical systems, which are not directly related to their Internet-facing perimeter; there are some exceptions, of course).

Yes yes, but I work at Google :-)

That said, looking back at previous jobs there are many places -- particularly in ad-tech stuff -- where I used Java server side that I now think C++ would have been more appropriate (or these days, Rust). I wasted a lot of hours tuning for garbage collection that I'd love to have back.

And yes, there is a crapload of stuff that is internet facing that is C++.

Re: Which companies are using Erlang, and why?

#148

Post by kitplummer » Mon, Sep 30, 2019, 2:30 PM UTC

Globz wrote: post #133

kitplummer wrote: post #129

Fairly blind question: does Erlang|Elixir and BEAM make any sense in a pseudo-embedded, edge compute or IoT environment with constrained resources (CPU and memory), or even ARM architecture? Aside from the developer-side things, if AMQP were to the centralized communications hub (e.g. RabbitMQ) does using Nerves on devices make any performance benefit - meaning BEAM and app(s) there? The intent would be pre-process d…

Yes, take a look at nerves : https://nerves-project.org/

Yep, know Nerves. Like the toolset and the model. Really asking about the underlying Erlang/Elixir that Nerves provides. The delivery flow (think image to SD card) fits the more tradition embedded/realtime model - versus OS, and installing app.

Re: Which companies are using Erlang, and why?

#149

Post by lagadu » Mon, Sep 30, 2019, 2:31 PM UTC

z3t4 wrote: post #31

Something I find interesting is that the tech stack is often chosen by non-engineers/founders. So languages and frameworks are marketed to business people. Freelance work is often weak on the requirements, but they have strong opinions on what language and framework to use.

That's often because most clients will already have some sort of environment set up, running some OS and with certain features installed and most importantly: they don't want to have 5 different projects working on 5 different frameworks because that'd be a nightmare to maintain. Once a company gets into a tech stack, they'll want to stay within it as much as possible and that makes plenty of sense.

Re: Which companies are using Erlang, and why?

#150

Post by defined » Mon, Sep 30, 2019, 3:00 PM UTC

ihuk wrote: post #84

We developed Online Charging System in Erlang that served couple million subscribers for close to three years. I found the whole experience fairly terrible. Erlang is nice enough language and I don't mind the syntax but it's also kinda cumbersome and verbose at times. For example, adding `true -> ok` to every if statement gets old fast. Similarly, Erlang/OPT is a nice platform but some parts are fairly bad. Looking a…

I can't refute your personal experience, but 10 years of Erlang work left me longing for more. It sounds as if perhaps Erlang was not used optimally, or, alternatively, best practices may not have been followed.

10 years ago the ecosystem was horrendous, and is much better now. Granted, the build experience could be better but I didn't find it that bad.

I find that people's experiences are relative to what they are accustomed to. Early years for me included compiling and linking C in Windows (segmented) and that was truly horrible!