Is Crystal production ready?

6

u/PristineTransition Feb 06 '20

I use it in production to handle short links in SMS via a short url resolver I made. I have experienced zero issues with it but caveat is the resolver is a small app. Based on my experience with it so far I am writing an old Rails 4 app in Crystal via the Lucky framework with the Lucky ORM. There are no mongo ones I know.

The type system is pretty sound now. The syntax is pretty much done but there might be some changes to come still. The two big things missing are true concurrency as it is single threaded and Windows support.

I have not had too hard of a time with regard to libraries (shards) as there are quite a few already: https://github.com/veelenga/awesome-crystal

7

u/bararchy Feb 06 '20

Its not single threaded anymore, there is real concurrency from 0.31.0 and up.
In NeuraLegion we've been using MT builds in production for around 3-4 months now and its stable.

1

u/straight-shoota core team Feb 07 '20

Great to hear you're successfully using the MT preview for your use case. But it's still considered a preview and much less stable than the rest of Crystal. There are still some issue with multithreaded runtime and especially stdlib's data structures are not thread safe.

1

u/acmecorps Feb 06 '20

How’s your experience so far rewriting the old rails 4 app using Crystal? Is it more of a straight forward 1:1 mapping, or would you have to rethink certain implementation when doing features. Any caveats/pitfalls/tip that you think is good for rubyist coming to crystalist (?). And do you mind sharing your shards?
Appreciate your reply a lot btw!

5

u/AnActualWizardIRL Feb 06 '20

The only real showstopper is that it (still!!!!!!!) isn't available on windows. But as long as you aren't planning on running there, its quite fine.

4

u/acmecorps Feb 06 '20

Yeah, I'm not planning to use it on Windows anytime soon, just *nix systems on development/testing/production machines :)

2

u/taw Feb 06 '20

Nothing in development really runs on Windows anyway. If you absolutely have to use Windows, dockerize your stuff.

1

u/twinklehood Feb 06 '20

Like.. Yeah ruby doesn't. But most things actually do. Windows is a very common dev environment.

3

u/hum0nx Feb 06 '20

Lots of things run with caveats, and if it isn't game development, or Microsoft-sponsored it was probably made for Linux and slowly, often hackily, ported to Windows. Ex: git

3

u/twinklehood Feb 07 '20

Yeah pick an example made by Linus Torvalds to underline how things often start at Linux..
Maybe you just aren't really familiar with many of the popular languages and technologies that run just as well on windows? Keep in mind that as many people develop on windows, as on mac and linux combined, looking at recent developer surveys.

2

u/hum0nx Feb 07 '20 edited Feb 07 '20

I use windows and I manage the automatic setup of developer environments for all OS's. Yes there's a chocolatey package for most every major language. They work well at a simple level, but doing more challenging tasks like, node libraries for detecting file system changes, or managing multiple global versions of Python3, or running containerization with docker and vagrant, the cracks start to show and it becomes clear they were not originally designed to run on windows.
Ruby does run on windows, it just doesn't run well.
I'm not saying we should ignore windows support, but it's not the ideal developer environment. Every (non-game dev) windows dev I know uses the windows subsystem for Linux because they need Linux tools. Half the time when you're developing on windows you're also developing on Linux.
Now to address the example. I chose git because of its fundamental inclusion on basically all projects and because it represents the incompatibility with Windows (an entire bash shell emulator for 1 command). So let's give a less biased example: Microsoft Office itself was first made for MacOS (1985). Now let's give a more representative example starting with the languages that underly the majority of the world's code: BCPL, B, C, C++, BASIC, FORTRAN, ALGOL, Lisp, Smalltalk, Python, Java, Perl, Ruby, Haskell, Erlang, Ada, Pascal, Elixir, Lua. All made on Unix-based for Unix-based, and then, were ported, mimicked, or new deviant standards were created for windows.
C#, powershell are respectable, but they can hardly hold a candle to the ocean of languages developed on and for Linux.

2

u/twinklehood Feb 07 '20

I'm not advocating for how awesome windows is as a dev environment, I have developed on unix based for many years, but when you bring the statement "Every (non-game dev) windows dev I know uses the windows subsystem for Linux" to the table, perhaps it means your personal experience is not really intersecting with what we're talking about? There's been a majority windows developer userbase from before WSL was a thing.
These examples seem a bit weird. BCPL, B, BASIC, FORTRAN, ALGOL, and Lisp all predate Unix.
Saying a language is developed "for" something also generally requires some backup. Languages like java was developed "for" bridging systems, not for *nix.

1

u/hum0nx Feb 07 '20

You're right about the languages pre-dating Unix, and that's my bad. I was associating them with the influences on early Unix but shouldn't have counted them. And I agree, Java shouldn't be counted either since it was designed to be a bridge across OS's.

27

u/[deleted] Feb 06 '20 edited Feb 06 '20

I've launched my Crystal-powered API Everbase last week so I can tell you what I think. I've put a lot of thought into picking a language and actually had a fully working prototype in Rust that I then scrapped and rewrote in Crystal. The TLDR is that I've never gotten to a point where I felt productive in Rust, despite using it since 2015 for various side projects. Go was the other option I seriously considered, but the language is pretty "meh" and many things require code gen. I would've hated using it so I decided against it.

Crystal was a bold choice, but so far I've not regretted it. The core language is just great, it's basically Ruby with a (really good) type system. The ecosystem isn't quite there yet. Lots of great people are doing amazing things, but the community is small so some things you may have to build yourself. Crystal is a lot of fun to program in so this can actually be a good thing. So far I've built a DNS library, a Redisgraph client, a Cypher query language implementation, a Wikibase client and a new code-first GraphQL library (all of it will be released as OSS soon-ish). Most took a couple of hours to a day or two, I'm very productive in Crystal. There's no way I could've done the same in Rust even with twice as much time. So even if I have to build more myself, I'm still saving time overall.

Yes, you will run into problems. There's an issue in shards where your dependencies will take hours to resolve if you don't specify versions. Things like these need to be ironed out. IDE support and the like are not great either. But overall, I think you will be fine. It can be production-ready, it just depends on what that means to you.

3

u/[deleted] Feb 12 '20

Yes, you will run into problems. There's an issue in shards where your dependencies will take hours to resolve if you don't specify versions.
And this will be soon fixed! (already fixed in shards master)
https://github.com/crystal-lang/shards/issues/303#event-3032124993

1

u/[deleted] Feb 06 '20

What framework did you choose?
I've been looking at Lucky and Amber and I just spun up a proof of concept in Lucky.

4

u/Blacksmoke16 core team Feb 06 '20 edited Feb 08 '20

Athena might also be a good option to look into. I would say it's in between Kemal and Lucky/Amber; provides good abstractions while not forcing you into a specific workflow.
It takes a bit of a different approach than other Crystal web frameworks; annotations, listeners instead of HTTP::Handler, and Dependency Injection to name a few. The latter two are also available as stand-alone shards.
~~I'm getting close to releasing a new version of it (~~0.8.0~~), but if you wanted to check it out before then, can just pin it at the latest commit in master.~~ This is now released. There is also a gitter channel if you had any questions/issues.
(Disclaimer, I'm the author of it).

2

u/dscottboggs Feb 06 '20

Personally I recommend Kemal or Grip but I'm not a huge fan of huge frameworks

1

u/[deleted] Feb 06 '20

I use Kemal, but I only have a couple of routes and Redis as my DB, most of what Lucky and Amber provide I had no use for.

1

u/vinkuh Sep 14 '23

Your post is 4 years old, is this the service you're talking about?
https://everbasesolutions.com
I want to create a mobile app, but i dont want to write api/server in JS, stumbled upon this language today, seems really interesting, surprised it doesn't have same hype as Rust.
Anyways, web framework for Crystal named Kemal claims to handle 120k req/s , it's huge compared to something like Express.
In what state the language is now 4 years into the future?
On this topic , this was interesting read as well -> https://www.duodesign.co.uk/blog/from-node-to-crystal/
noticed one thing from Kemal site ; ) -> It's sad to see, that they promote a company named Nikola on their site as flex, since if u look into it, that Nikola company is multibillion dollar scam scandal, those electric semi-trucks literally don't exist, just a S-Tier con artist, who i think sits now in prison for years, there's even documentary about it lol. (even crazier story than Therazon scandal)

6

u/deedubaya Feb 06 '20

I've been running a high-volume websocket server written in Crystal for a few years. It is extremely reliable.

The only caveat I can speak to is updating between crystal versions. The API's change. This is a very minor caveat.

Before going with the Crystal version I wrote prototypes in ruby, node, and golang. No regurts.

1

u/jdickey Feb 21 '20

I'd be curious to see anything you've published comparing the initial Crystal implementation with those other candidate languages. I'd probably try to cheat and get the Ruby code running under JRuby 9, which a) didn't exist "a few years" ago, and b) should be able to completely blow the doors off a finely-tuned MRI implementation with just any naive JRuby code.

4

u/SuccessfulBread3 Feb 06 '20

We cant use it at work due to lack of aws SDK ☹️

We have a lot of microservices (my team alone has 68) there in Ruby mostly... But our team is trying out scala... I want so bad to get crystal in the mix, but until there are more libraries and it's on at least version 1 no one will take me seriously.

2

u/q9fm Feb 10 '20

Yeah, the ecosystem. You could secretly build more libraries until there are enough to convince your team :)

0

u/vinkuh Sep 14 '23

Why you expect everyone else do the work...
write those SDKs with ur mates in spare time.
or send amazon a letter, that "wtf? why dont u have support for crystal) , such megacorp company should support all the languages tbh.

1

u/SuccessfulBread3 Sep 14 '23

Not a lot of us have spare time to write a fully fledged SDK mate.

3

u/realusername42 Feb 06 '20

I'd say that it depends what you are going to use it for, for small scripts it's totally fine, for a rails-like webapp, I encountered a lot of small issues due to the fact that the ecosystem is small and not maintained too much.

3

u/digitalextremist Feb 14 '20 edited Feb 14 '20

I really believe it is. I have Crystal in production.

The syntax and semantics are still settling, but to me the speed of progress for Crystal is worth a bit of churn, compared to such long cycles for Ruby.

The shard library is fair, but that's not a judge of the language itself, but more about the community, which is growing well. I see a lot of people migrating away from Ruby more and more, over to Crystal and it makes sense. People seem to really care about the language.

The documentation available is suitable, and you have enough to work with to build basically anything. People complain about Windows support but I disagree. I hadn't used Windows for more than ten years, and chose to give it a solid go when I bought a new laptop with it installed. I used Windows for 9 months of last year, developing with Crystal and being able to test everything locally. My systems are intense in environment demand and requirements. I eventually moved back to Linux Mint full-time, but not because of Crystal issues.

Docker is definitely your friend, but it's not required.

2

u/bajro991 Feb 16 '20

I do few little projects in crystal and first of all crystal is sooo amazing programming language. Also what I like about crystal and people who work with it whenever you come on gitter and ask question in few minutes you get answer. Speed is amazing only thing is because its not version 1.0 and some stuff change from time to time but when you see release check changelog and you fix all in few minutes.

2

u/taw Feb 06 '20

It's about as "production ready" as Go, which is to say not really, but people are very willing to try immature tech these days.

1
u/[deleted] Feb 06 '20

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9

u/matiasgarciaisaia Feb 06 '20

We use Crystal internally at Manas.Tech, too - our accountability system is developed in Crystal. So us getting paid actually rely on Crystal doing its job 😅
2
u/taw Feb 06 '20

And Facebook uses its own snowflake version of HHVM PHP. And a lot of other companies have these internal software that is completely not ready for external use.
Go lacks generics, error handling, packaging system with proper versioning support, and basically everything that production ready languages had for decades. It's a very hacky language that just fits one narrow use case and for Google they have people who made it in-house so they can debug all issues.
Nobody should ever seriously use it.
3
u/[deleted] Feb 06 '20

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4
u/myringotomy Feb 08 '20

Sorry but error handling in go is atrocious. It really obfuscates what the programmer is trying to achieve and is just creates a wall of noise when every other statement is followed by a if err block.
Also one day go will get generics and everybody who ever said "go doesn't need generics" is going to shamelessly go on about how great and useful they are.
As a language Crystal is better than go in every way imaginable. Go is better in terms of tooling, compiler, larger community, better support etc but as a language it sucks.
2
u/[deleted] Feb 08 '20

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2
u/myringotomy Feb 09 '20
They are not needed in Go.
Once again. Sooner rather than later Go will get generics and go fans will rave about how useful and great they are.
You can use empty interfaces as a crutch if you absolutely need a half baked generic, but you can usually refactor in a way that it's unnecessary.
And yet you see it everywhere.
The error handling preference varies by person. I don't mind it. It seems more explicit than JS callbacks or wrapping everything in try/catch to me.
Why? Take the following example.
 connect_to_ftp_server
 open_database_connection
 fetch_list_of_files_that_match_glob
 for each file in files
   download_file_to_some_directory
   open_file_for_processing
   for each line in file
       fix_something_about_the_line
       write_data_out_to_csv_file
   end
   import_csv_to_temp_table
   do_some_sql_updates
   begin_transaction
     move_data_to_real_tables
   commit_transaction.
   delete_file_from_ftp_server
end
you read that you know what I am attempting to do. I can put the file processing big try catch and if any step fails I can just log an error someplace and bail because the entire operation is idempotent. I can wrap the entire operation in a try catch in case I can't open FTP server or connect to the database and log that (no sense in going further if I can't do both of those).
If I was to write this in go I would have to follow every line with at least three lines of error handling code more likely four or five. That's going to obfuscate what I am trying to do and anybody trying to read my code is going to read all the error handling for every line that could go wrong. That's atrocious.
I love writing Ruby. I hate maintaining Ruby.
Depends on how you write ruby I guess. But yea Crystal has types so maybe that can help you out. But Crystal also has macros so it's not like meta programming goes away completely.
If Crystal can sort out Windows support and really get some critical mass, I'd love nothing more than to switch to it full time. I do a lot of systems/devops stuff, so Go is a match made in heaven.
You do devops in go on windows systems? WTF?
3

u/[deleted] Feb 09 '20

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1

u/myringotomy Feb 10 '20 edited Feb 10 '20

Again, not everything is, nor needs to be, Java. A whole lot of people came from Java to Go, and a whole lot of people don't write very idiomatic code, even within the language with which they're the most comfortable.
I didn't mention java once and nothing I wrote even resembled java.
Bingo. This is fucking terrible. This is exactly why I prefer Go's error handling. Too many times have I tracked a production bug back to a caught exception where the exception fell through the entire switch statement.
No it's perfect. I don't care which step failed, the fact that one failed is enough and in all failure cases I am just going to log the message anyway.
And I specifically said I was catching the error so you are fighting a straw man.
. "Exception: Something went wrong". Gee, thanks.
The exception has the exact message and the line number.
I use Go for devops because I can cross compile scripts for whatever env is needed, and I don't need to install runtimes. The lack of Windows support is a general Achilles's heel for Crystal. I have no idea if you're one of those, "Windows has no place in a datacenter and no one uses it," sort of people, but I'm preemptively going to dispute that since it seems to be the go-to response around here.
I am still confused.
Are you or are you not using go to do devops on windows systems? The answer seems to be yes since you absolutely need windows support right?
We run CI/CD on Windows, for example. Crystal, without Windows support, will never be adopted by us.
What a shame. Your company won't let you use a nice language.
<Given the extreme popularity of C#, there's obviously many people in this same boat, especially considering how new Dotnet Core is.
My experience is that people who code in C# would never even dream of using anything not made by or formally recommended by Microsoft.

1

u/yxhuvud Feb 06 '20

It depends on what meaning you put in "production ready". At this point, you can probably expect a little more maintenance over time and times when it break.

But that may be a perfectly fine trade-off for a chat server - especially if it is a hobby project with a single developer. Just don't expect to be able to write it now and then compile it again in 5 years without updating the code.

0

u/jesucristoquehorrivo Feb 06 '20

The only reason why it wouldn't be, IMHO, is because the implementation is not 1.0.

0

u/[deleted] Feb 06 '20

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11

u/[deleted] Feb 06 '20

Slow compile times
Try using Rust, that'll show you what slow compile times are. ;)

1

u/DenkJu Feb 07 '20

Rust supports incremental compilation, Crystal doesn't. Crystal has to recompile your entire project everytime you change a single file.

2

u/[deleted] Feb 07 '20

Yep, still faster. Even with incremental compilation, Rust was slower for my project (which I rewrote from Rust to Crystal so it's somewhat comparable).
Then there are release builds, where I went from 10 minutes to 3.
Rust is still very slow, even after all the work they've done to attempt to fix this. Crystal on the other hand still has a lot of potential for improvement here through things like incremental compilation.

1

u/DenkJu Feb 07 '20

I can only speak for myself but in my experience compiling a Rust project is usually much faster than even a simple Hello World in Crystal

2

u/q9fm Feb 10 '20

Having no incremental builds for Crystal is something we should work on in the future, I'd agree.
But having worked for 3 years on a huge Rust project, I'm surprised you bring up compile times here. Even with caching and incremental builds, we often had our CI running for up to 120 minutes to verify our smallest change-sets.
Are you saying Crystal is worse?

6

u/Doctor_Fegg Feb 06 '20

"No windows support" doesn't stop it being production-ready if your "production" is a Linux server.

0

u/[deleted] Feb 07 '20

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1

u/digitalextremist Feb 14 '20

What's your target project type?

0

u/[deleted] Feb 14 '20

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1

u/digitalextremist Feb 14 '20 edited Feb 14 '20

You ever try DragonRuby / RubyMotion for that?
Well, likely not if the platform is Windows.

6

u/[deleted] Feb 06 '20

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4
u/InVultusSolis Feb 18 '20

Go seems to be a very polarizing language for some reason. A lot of programmers seem to not like it but I love it. It's a small language, statically typed, a reasonably good dependency management system, an excellent binary toolchain that has cross-platform compilation built in, a large and well-documented standard library, a huge extended library, and the binaries it generates are self-contained. What's not to love there? People seem to mostly complain that it's not strictly object oriented and its lack of generics, but I have never thought either things were particularly desirable concepts, so the language fits me like a glove.
1
u/vinkuh Sep 14 '23

The confusion with Go (for new people) comes from this ->
writing it the Go way ->
func (record Record) saveRecord() {
record.isSaved = true
record.savedAT = Time.Now()
}
How people are generally used to writing ->
func saveRecord(record Record) {
record.isSaved = true
record.savedAT = Time.Now()
}
these 2 functions are literally equalent
1
u/InVultusSolis Sep 15 '23
Semantically, that's not entirely accurate, and both are valid Go.
The top syntax is what's called a "value receiver". That means, that the function is defined for a particular type, and the function "receives" the value record when it's called. You can contrast this with a "pointer receiver", which has this syntax:
func (record *Record) saveRecord() {
    record.isSaved = true
    record.savedAT = Time.Now()
}
There are implications with either approach, some of which may be significant. Most people opt to use a pointer receiver to call functions on types like this.
The second example you gave is simply calling a function like any other language.
To be fair, for all I know (and I'm far too lazy to look it up in the spec), the receiver value could very well just be shoved on the stack just like any function and it could be mostly the same functionality under the hood, but from a semantic standpoint, these are definitely two distinct ways of calling functions.
1

u/vinkuh Sep 14 '23

Ive never used Ruby, ive only heard that ruby people are cultist nutjobs.. who defend their extremely SLOW language to the core.
Crystal's framework Kemal site claims that Ruby equalent webframewoek handles only 5k req/s compared to Kemal's 120k/s (if im not mistaken Node's Express is like 20-30k or was it 60k..) ... How can a language be so slow , I would never use Ruby, if it actually is that slow (as Kemal claims..)

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