Erlang/OTP by Example

#1

Post by jxub » Sat, Oct 20, 2018, 6:34 PM UTC

Erlang/OTP by Example
erlangbyexample.org

Re: Erlang/OTP by Example

#2

Post by xq3000 » Sat, Oct 20, 2018, 6:37 PM UTC

Cool site!

PS: Content looks cropped on an iPhone 7 nonmatter how you resize it

Re: Erlang/OTP by Example

#3

Post by jlouis » Sat, Oct 20, 2018, 7:46 PM UTC

If you get to the part about monitors, consider erlang:demonitor(Ref, [flush]) in your own code. This also removes the monitor message from your mailbox if it arrived in between, which is a real problem in an async setting.

Though in some situations, it is better to just ignore the spurious message when it arrives by tracking what monitors you have enabled in the process state. Unkonwn monitors are just gracefully ignored. The same pattern is useful with timeouts as well. Cancel the timeout, but if it arrives in your mailbox while the cancel is happening, you can just detect an old timeout and ignore it.

Re: Erlang/OTP by Example

#4

Post by davidw » Sat, Oct 20, 2018, 7:46 PM UTC

This is also a fantastic Erlang learning resource: https://learnyousomeerlang.com/

Re: Erlang/OTP by Example

#5

Post by ilovecaching » Sat, Oct 20, 2018, 8:17 PM UTC

As someone who has worked two jobs now writing, deploying, and operating Erlang clusters, I recommend switching to Rust. Erlang requires a lot of TLC to get right, it's super slow, and it's hard to burst. Like, super hard to burst. Erlang nodes are meant to cluster as a k graph and never go down. Modern ops, especially container ops, does availability through ephemerality of services. The BEAM just doesn't like to be treated like cattle. Also Erlang has notoriously bad error messages, very little abstraction, and converting between binary strings and lists is a pain. Gaining Erlang operational knowledge also takes a while. We eventually had to rewrite things like gen_server, ditch mnesia etc. as we scaled.

So why Rust? Like Erlang, it's damn good at concurrency and enables functional programming. It also enables event driven programming through tokio, which is a better fit for web servers than green threads (you're mostly waiting on the network). Unlike Erlang, it's super fast (even at math), has a great type system, amazing error messages, low memory usage, and the community is already quite a bit bigger.

Re: Erlang/OTP by Example

#6

Post by dev_dull » Sat, Oct 20, 2018, 8:21 PM UTC

ilovecaching wrote: post #5

As someone who has worked two jobs now writing, deploying, and operating Erlang clusters, I recommend switching to Rust. Erlang requires a lot of TLC to get right, it's super slow, and it's hard to burst. Like, super hard to burst. Erlang nodes are meant to cluster as a k graph and never go down. Modern ops, especially container ops, does availability through ephemerality of services. The BEAM just doesn't like to be…

The world of ephemeral containers really has changed the dynamic. Erlang solves a lot of problems with good solutions, but writing good software is only part of the battle. Lifecycle management, monitoring, etc make up a huge operational burden and should always be thought of as first-class problems in language design. Rust makes that better in many ways but not uniquely better than alternative languages.

Re: Erlang/OTP by Example

#7

Post by abledon » Sat, Oct 20, 2018, 8:23 PM UTC

ilovecaching wrote: post #5

As someone who has worked two jobs now writing, deploying, and operating Erlang clusters, I recommend switching to Rust. Erlang requires a lot of TLC to get right, it's super slow, and it's hard to burst. Like, super hard to burst. Erlang nodes are meant to cluster as a k graph and never go down. Modern ops, especially container ops, does availability through ephemerality of services. The BEAM just doesn't like to be…

What is TLC?

Re: Erlang/OTP by Example

#8

Post by phyrex » Sat, Oct 20, 2018, 8:24 PM UTC

xq3000 wrote: post #2

Cool site! PS: Content looks cropped on an iPhone 7 nonmatter how you resize it

Yep, completely unusable on mobile

Re: Erlang/OTP by Example

#9

Post by ilovecaching » Sat, Oct 20, 2018, 8:27 PM UTC

abledon wrote: post #7

ilovecaching wrote: post #5

As someone who has worked two jobs now writing, deploying, and operating Erlang clusters, I recommend switching to Rust. Erlang requires a lot of TLC to get right, it's super slow, and it's hard to burst. Like, super hard to burst. Erlang nodes are meant to cluster as a k graph and never go down. Modern ops, especially container ops, does availability through ephemerality of services. The BEAM just doesn't like to be…

What is TLC?

Tender loving care

Re: Erlang/OTP by Example

#10

Post by kauboy » Sat, Oct 20, 2018, 8:31 PM UTC

ilovecaching wrote: post #5

As someone who has worked two jobs now writing, deploying, and operating Erlang clusters, I recommend switching to Rust. Erlang requires a lot of TLC to get right, it's super slow, and it's hard to burst. Like, super hard to burst. Erlang nodes are meant to cluster as a k graph and never go down. Modern ops, especially container ops, does availability through ephemerality of services. The BEAM just doesn't like to be…

What do you think of Elixir?