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Lovely Week with Elixir

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Re: Lovely Week with Elixir

#61

Post by ch4s3 »

dpeck wrote: post #51
ch4s3 wrote: post #24

Earlier quoted context omitted.

> 1. Ecto is simply the best DB library I've encountered in any language. I'd almost recommend learning Elixir just to be able to use Ecto. It's interesting, people always talk about Phoenix, which is nice, but Ecto is really special. I often recommend it to anyone who is feeling burned by Active Record implementations.

Changesets are beautiful. And they're great for general structure validation outside of databases as well.

Oh yeah, absolutely. They're great for building API clients.

Re: Lovely Week with Elixir

#62

Post by dnautics »

skeletal88 wrote: post #57
biggestlou wrote: post #17

I learned Elixir a few weeks ago as a quarantine self-improvement project and pretty much loved it. There are some warts, as in any language. As someone who's primarily worked in Go and Java in the past and has also been learning Rust I don't super love the optional typing thing, and I end up missing higher-level data constructs like interfaces and traits. But there are some great language features, like guards and p…

Interesting. I really like Python and SqlAlchemy. Changing objects in the database via changesets and applying them on top of eachother feels kinda alien, when I can't do object.property = something. The thing that confuses me most about Phoenix and Elixir is how do I actually deploy the application to production? I have my own server where I can run whatever I want (running Ubuntu), so what do I have to do to get my…

Doing object.property = something is, I think a mental anti-pattern because it engenders uncertainty about which source of information holds the truth (local object or database), and now you have a needless (mental) distributed state problem. At least in a system with bare structs and changesets, especially in an immutable language, there's no ambiguity about the fact that your data are stale the minute you drive it off the dealership lot and your data synchronization events must pass through a single explicit point of entry. Explicit is better than implicit, after all.

To answer your second question, that's not entirely easy to answer, but I personally use mix release command, ship it to s3 as a tar.gz, then pull it down into the server, unzip, put the command line entry point "start" (there are instructions when you do mix release) into a systemd service, and it's good to go. Couldn't be easier. It takes us several ansible scripts, and annoying wrangling with virtualenvs if something goes wrong for us to create a new Ubuntu Django server from scratch and literally two commands (one is a 5 line shell script) to get Elixir up and running.

Re: Lovely Week with Elixir

#63

Post by polmuz »

PascalW wrote: post #43
ashton314 wrote: post #22

The BEAM is a huge win: having lightweight threads means you can often do away with things like Redis for job queues and PubSub stuff. I love this answer on StackOverflow by Elixir's creator: https://stackoverflow.com/questions/32085258/how-can-i-sched... So simple. Something that would require a job queue and a job runner fades away into a piece of the OTP application tree. When it crashes, it will even come right b…

I don't really understand this sentiment of not needing a queue system. This is not much different from spawning a thread in Java to delay the email sending. For any serious application you want a job like that to be persisted so you can guarantee it runs even if your application is restarted. I know that Erlang/Elixir is designed for stateful applications and if you have a cluster and do hot deploys this is less of…

Having a queue means you have a distributed system. How do you handle network problems, errors/retries, back pressure? OTP has excellent idiomatic tools for all that and more.

Re: Lovely Week with Elixir

#64

Post by ch4s3 »

skeletal88 wrote: post #57
biggestlou wrote: post #17

I learned Elixir a few weeks ago as a quarantine self-improvement project and pretty much loved it. There are some warts, as in any language. As someone who's primarily worked in Go and Java in the past and has also been learning Rust I don't super love the optional typing thing, and I end up missing higher-level data constructs like interfaces and traits. But there are some great language features, like guards and p…

Interesting. I really like Python and SqlAlchemy. Changing objects in the database via changesets and applying them on top of eachother feels kinda alien, when I can't do object.property = something. The thing that confuses me most about Phoenix and Elixir is how do I actually deploy the application to production? I have my own server where I can run whatever I want (running Ubuntu), so what do I have to do to get my…

1. It's a functional thing, it's quite nice after you use it for a bit, and really powerful because you can use it for any data, and not just when working with a DB.

2. There are several ways. You can use releases [1]; copy the code to the box, run mix release, then ./app start, and point whatever you want to that process. If you're running phoenix you could always compile it on the box and just run mix phx.server. I wouldn't do that though. You could also use a tool like distillery[2] which is kind of like releases. There is another more esoteric option where you build locally without the runtime, but I wouldn't recommend that.

[1] https://elixir-lang.org/getting-started/mix-otp/config-and-r...

[2] https://hexdocs.pm/distillery/tooling/cli.html

Re: Lovely Week with Elixir

#65

Post by depr »

skeletal88 wrote: post #57
biggestlou wrote: post #17

I learned Elixir a few weeks ago as a quarantine self-improvement project and pretty much loved it. There are some warts, as in any language. As someone who's primarily worked in Go and Java in the past and has also been learning Rust I don't super love the optional typing thing, and I end up missing higher-level data constructs like interfaces and traits. But there are some great language features, like guards and p…

Interesting. I really like Python and SqlAlchemy. Changing objects in the database via changesets and applying them on top of eachother feels kinda alien, when I can't do object.property = something. The thing that confuses me most about Phoenix and Elixir is how do I actually deploy the application to production? I have my own server where I can run whatever I want (running Ubuntu), so what do I have to do to get my…

Use edeliver https://github.com/edeliver/edeliver

Re: Lovely Week with Elixir

#66

Post by moreaccountspls »

PascalW wrote: post #43
ashton314 wrote: post #22

The BEAM is a huge win: having lightweight threads means you can often do away with things like Redis for job queues and PubSub stuff. I love this answer on StackOverflow by Elixir's creator: https://stackoverflow.com/questions/32085258/how-can-i-sched... So simple. Something that would require a job queue and a job runner fades away into a piece of the OTP application tree. When it crashes, it will even come right b…

I don't really understand this sentiment of not needing a queue system. This is not much different from spawning a thread in Java to delay the email sending. For any serious application you want a job like that to be persisted so you can guarantee it runs even if your application is restarted. I know that Erlang/Elixir is designed for stateful applications and if you have a cluster and do hot deploys this is less of…

Slightly offtopic, but consider a pattern of persisting the state machine of a given task instead of the task queue itself. For example, for a daily email job, you might have three states: UNSENT, BEGIN(begin_time), SENT. Then you can just have a supervisor job that scans your table or whatever and schedules jobs, retries, etc. as needed. Now you don't have to worry about the queue state at all!

Re: Lovely Week with Elixir

#67

Post by ninjakeyboard »

Scramblejams wrote: post #20
ninjakeyboard wrote: post #7

Elixir is decent and I've worked with it a fair amount in production systems... Mostly Rubyists seem to really click with it. And ruby idioms are all over it - you can taste its history and proximity to ruby's ecosystem. As a scala dev that ended up working with elixir for a couple years, my opinion is that a typesafe elixir-like language would really bring BEAM back into the mainstream. Akka is alright but it's shoe…

The older I get the grumpier runtime errors make me. I want ReasonML (language!) and Erlang (OTP!) to have a baby, and I want it birthed by the Go runtime. (Go? Yeah, Go. I don't love the language, but I am a lover of low latency and garbage collection, what can I say?) Yes, there's Gleam, but if something's based on BEAM, the throughput generally won't impress. :-( Would seem a shame to do all that static typing, an…

"I think there's a sweet spot for a language that accepts mutability inside of actors, but only allows immutable objects to be sent as messages, with an escape hatch available if needed."

That's kind of what akka is on scala or java. Messages are immutable _BY CONVENTION_ but you can do whatever you want.

Re: Lovely Week with Elixir

#68

Post by jeremyjh »

polmuz wrote: post #63
PascalW wrote: post #43

Earlier quoted context omitted.

I don't really understand this sentiment of not needing a queue system. This is not much different from spawning a thread in Java to delay the email sending. For any serious application you want a job like that to be persisted so you can guarantee it runs even if your application is restarted. I know that Erlang/Elixir is designed for stateful applications and if you have a cluster and do hot deploys this is less of…

Having a queue means you have a distributed system. How do you handle network problems, errors/retries, back pressure? OTP has excellent idiomatic tools for all that and more.

Elixir developers who need a queue generally reach for Rabbit (which any language can use), or something backed in a database like rihanna[1] or honeydew[2]. Rolling your own distributed system is very much a last resort, and despite its excellent concurrency characteristics the BEAM still lacks basics such as a battle-tested raft implementation.

[1]https://github.com/samsondav/rihanna [2]https://github.com/koudelka/honeydew

Re: Lovely Week with Elixir

#69

Post by joeyspn »

ch4s3 wrote: post #64
skeletal88 wrote: post #57

Earlier quoted context omitted.

Interesting. I really like Python and SqlAlchemy. Changing objects in the database via changesets and applying them on top of eachother feels kinda alien, when I can't do object.property = something. The thing that confuses me most about Phoenix and Elixir is how do I actually deploy the application to production? I have my own server where I can run whatever I want (running Ubuntu), so what do I have to do to get my…

1. It's a functional thing, it's quite nice after you use it for a bit, and really powerful because you can use it for any data, and not just when working with a DB. 2. There are several ways. You can use releases [1]; copy the code to the box, run mix release, then ./app start, and point whatever you want to that process. If you're running phoenix you could always compile it on the box and just run mix phx.server. I…

+1 for distillery, very convenient...

https://github.com/bitwalker/distillery

Re: Lovely Week with Elixir

#70

Post by overkalix »

ninjakeyboard wrote: post #67
Scramblejams wrote: post #20

Earlier quoted context omitted.

The older I get the grumpier runtime errors make me. I want ReasonML (language!) and Erlang (OTP!) to have a baby, and I want it birthed by the Go runtime. (Go? Yeah, Go. I don't love the language, but I am a lover of low latency and garbage collection, what can I say?) Yes, there's Gleam, but if something's based on BEAM, the throughput generally won't impress. :-( Would seem a shame to do all that static typing, an…

"I think there's a sweet spot for a language that accepts mutability inside of actors, but only allows immutable objects to be sent as messages, with an escape hatch available if needed." That's kind of what akka is on scala or java. Messages are immutable _BY CONVENTION_ but you can do whatever you want.

Isn't that the basis/point of the actor model? Actors can message each other and processing the message can trigger state mutation of the recipient, but they can't directly mutate each other.
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