6 ms·

Low-level web programming in Racket and a wiki in 500 lines

135 points by ihodes 11y ago

networked 11y ago
How fast is web-server/servlet? Is it fit for production use? Last time I checked (which was, admittedly, a long time ago) it served noticeably fewer "hello, template world" requests per second than Flask running on Python 2.7 while using more RAM. This was a pity to me because I thought Racket could otherwise be a very interesting language for web development.
mkozlows 11y ago
I'm glad to see someone talking about using the lower-level web libraries in Racket. The high-level continuation-based ones are ridiculously unsuitable for actual web programming (they store full state on the server at all times, and the URL gives you full access to the session, among other issues), but the lower-level ones actually look pretty clean and modern. And yet all the documentation keeps talking about the continuation stuff, bizarrely.
- minikomi 11y ago
  Indeed. I have fun making little web apps which serve a small single purpose and can be run from a single script[0] - templating using response/xexpr with paredit is.. well.. fun! Speed isn't a problem since I cache the result behind nginx - these aren't mission critical apps. [0] Tokyo Art Parties parsed out of Tokyo art beat events xml - https://github.com/minikomi/tokyoartparties-rkt/blob/master/artparties.rkt https://github.com/minikomi/tokyoartparties-rkt/blob/master/...
- shriramkmurthi 11y ago
  The continuation-based libraries are the simplest, easiest, quickest way to get a program off the ground. They make interactive Web programming just as easy as writing “scanf” or its equivalent, _and_ are safe in the face of various browser interactions. Therefore, they're a good default for prototyping. However, I agree that they also have issues, and the documentation should not over-emphasize them, but rather indicate what they are suitable for and what not and make clearer to readers a transition path out of there.
  - mkozlows 11y ago
    I think that depends on where you're coming from. If you're a longtime web developer, stateless request/response are in your blood, and stateful, persistent programming is deeply weird.
- jeapostrophe 11y ago
  The issues you mention are all alleviated by the stateless continuations which do not store state on the server and allow various ways of closing off the session from simply having the URL. The documentation discusses the features of the Web framework, many of which have to do with its unique aspects. As you can see in this post, all normal Web programming is possible and easy, but there's very little special to say about it, because it's just a normal program.
  - mkozlows 11y ago
    "It's just normal" is a thing that I think is good to communicate. Being able to use Racket to write web apps in ways that wouldn't be unfamiliar to Node devs makes the Lispy thing seem less weird and intimidating.
nosefrog 11y ago
This is very useful. I'm in the middle of a Racket web project right now and I got hung up on parsing/processing form data. The Racket docs are very thorough, but they can be confusing if you don't know what you're looking for. If anyone here has experience with web stuff in Racket, I've set up a small skeleton for Racket web projects: https://github.com/samertm/web-project-bootstrap.rkt https://github.com/samertm/web-project-bootstrap.rkt Right now it contains skeletons for talking to sqlite, setting up a router and handlers, and manipulating the web server from the command line. I need to add an ORM (I'm not sure if Racket has any up-to-date ORMs?) and static file handlers. I'd love help or feedback!
- bliti 11y ago
  From you experience, how is performance? what would you compare it too? The examples ae useful, thank you.
  - nosefrog 11y ago
    I haven't written any big projects in Racket, so I can't say how it fares on real-world projects with real-world data, but here are the results for a very minimal Racket project using ApacheBench: ~ $ ab -n 100 -c 10 "http://localhost:8888/" http://localhost:8888/" This is ApacheBench, Version 2.3 <$Revision: 1638069 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ http://www.zeustech.net/ Licensed to The Apache Software Foundation, http://www.apache.org/ http://www.apache.org/ Benchmarking localhost (be patient).....done Server Software: Racket Server Hostname: localhost Server Port: 8888 Document Path: / Document Length: 89 bytes Concurrency Level: 10 Time taken for tests: 0.084 seconds Complete requests: 100 Failed requests: 0 Total transferred: 26800 bytes HTML transferred: 8900 bytes Requests per second: 1192.32 [#/sec] (mean) Time per request: 8.387 [ms] (mean) Time per request: 0.839 [ms] (mean, across all concurrent requests) Transfer rate: 312.05 [Kbytes/sec] received
    - SanFranManDan 11y ago
      Without a baseline comparison against other servers with same functionality on the same computer, these results mean nothing. For example here are benchmarks from Django's single-threaded debug webserver: Benchmarking 127.0.0.1 (be patient).....done Server Software: WSGIServer/0.1 Server Hostname: 127.0.0.1 Server Port: 8000 Document Path: / Document Length: 2 bytes Concurrency Level: 10 Time taken for tests: 0.100 seconds Complete requests: 100 Failed requests: 0 Total transferred: 16400 bytes HTML transferred: 200 bytes Requests per second: 998.90 [#/sec] (mean) Time per request: 10.011 [ms] (mean) Time per request: 1.001 [ms] (mean, across all concurrent requests) Transfer rate: 159.98 [Kbytes/sec] received Or Nginx returning the same thing: Benchmarking 127.0.0.1 (be patient).....done Server Software: nginx/1.6.2 Server Hostname: 127.0.0.1 Server Port: 9080 Document Path: /gangam Document Length: 14 bytes Concurrency Level: 10 Time taken for tests: 0.013 seconds Complete requests: 100 Failed requests: 0 Total transferred: 15600 bytes HTML transferred: 1400 bytes Requests per second: 7478.31 [#/sec] (mean) Time per request: 1.337 [ms] (mean) Time per request: 0.134 [ms] (mean, across all concurrent requests) Transfer rate: 1139.27 [Kbytes/sec] received
baldfat 11y ago
Just being exposed to Racket last month I was extremely surprised at how well it clicked with me as opposed to Haskel which I tried to learn for a few months on my own and just tried out SML and it moved to Racket. Can't put a finger on it but Racket just makes sense to me.
- nosefrog 11y ago
  I felt the same way, Racket is ridiculously fun to use! :)
- snissn 11y ago
  Have you tried python..? You might like it
  - baldfat 11y ago
    I was trying to get exposure to functional programming. Yes I use Python (less and less) for many years, but I certainly wish there was a python when I was a teenagers.
  - shriramkmurthi 11y ago
    Racket and Python aren't even remotely comparable as languages. Python is a far less sophisticated language with far richer libraries, and Racket is vice versa.
cneu 11y ago
Very nice proof of concept. Just a word of warning: In practice you want to sanitize your input. The code in "Serving static files" allows to break out of document-root with "..".
- brlewis 11y ago
  Have you tried to actually exploit that? I don't currently use Racket myself, but I would expect request-uri to prevent ".." and if it didn't surely url-path would. ; extract the URI from the request: (define uri (request-uri req)) ; extract the resource from the URI: (define resource (map path/param-path (url-path uri))) ; find the file location: (define file (string-append document-root "/" (string-join resource "/")))
59nadir 11y ago
Isn't your `any?` function actually `ormap`[0]? You should be able to do the same thing with: (ormap password-matches? line) 0 - http://docs.racket-lang.org/reference/pairs.html?q=ormap#%28def._%28%28lib._racket%2Fprivate%2Fmap..rkt%29._ormap%29%29 http://docs.racket-lang.org/reference/pairs.html?q=ormap#%28...
- mattmight 11y ago
  Yep! Jay McCarthy pointed this out, and I changed it. :)
octatoan 11y ago
Hijacking: Can anyone tell me how to make a Scribble website have CSS like in HTDP?
- jeapostrophe 11y ago
  Extra CSS can be added when running Scribble: http://docs.racket-lang.org/scribble/config-style.html?q=css http://docs.racket-lang.org/scribble/config-style.html?q=css

135 points by ihodes 11y ago

How fast is web-server/servlet? Is it fit for production use? Last time I checked (which was, admittedly, a long time ago) it served noticeably fewer "hello, template world" requests per second than Flask running on Python 2.7 while using more RAM. This was a pity to me because I thought Racket could otherwise be a very interesting language for web development.

mkozlows 11y ago

I'm glad to see someone talking about using the lower-level web libraries in Racket. The high-level continuation-based ones are ridiculously unsuitable for actual web programming (they store full state on the server at all times, and the URL gives you full access to the session, among other issues), but the lower-level ones actually look pretty clean and modern. And yet all the documentation keeps talking about the continuation stuff, bizarrely.

minikomi 11y ago
Indeed. I have fun making little web apps which serve a small single purpose and can be run from a single script[0] - templating using response/xexpr with paredit is.. well.. fun! Speed isn't a problem since I cache the result behind nginx - these aren't mission critical apps. [0] Tokyo Art Parties parsed out of Tokyo art beat events xml - https://github.com/minikomi/tokyoartparties-rkt/blob/master/artparties.rkt https://github.com/minikomi/tokyoartparties-rkt/blob/master/...
shriramkmurthi 11y ago
The continuation-based libraries are the simplest, easiest, quickest way to get a program off the ground. They make interactive Web programming just as easy as writing “scanf” or its equivalent, _and_ are safe in the face of various browser interactions. Therefore, they're a good default for prototyping. However, I agree that they also have issues, and the documentation should not over-emphasize them, but rather indicate what they are suitable for and what not and make clearer to readers a transition path out of there.
- mkozlows 11y ago
  I think that depends on where you're coming from. If you're a longtime web developer, stateless request/response are in your blood, and stateful, persistent programming is deeply weird.
jeapostrophe 11y ago
The issues you mention are all alleviated by the stateless continuations which do not store state on the server and allow various ways of closing off the session from simply having the URL. The documentation discusses the features of the Web framework, many of which have to do with its unique aspects. As you can see in this post, all normal Web programming is possible and easy, but there's very little special to say about it, because it's just a normal program.
- mkozlows 11y ago
  "It's just normal" is a thing that I think is good to communicate. Being able to use Racket to write web apps in ways that wouldn't be unfamiliar to Node devs makes the Lispy thing seem less weird and intimidating.

nosefrog 11y ago

This is very useful. I'm in the middle of a Racket web project right now and I got hung up on parsing/processing form data. The Racket docs are very thorough, but they can be confusing if you don't know what you're looking for. If anyone here has experience with web stuff in Racket, I've set up a small skeleton for Racket web projects: https://github.com/samertm/web-project-bootstrap.rkt https://github.com/samertm/web-project-bootstrap.rkt Right now it contains skeletons for talking to sqlite, setting up a router and handlers, and manipulating the web server from the command line. I need to add an ORM (I'm not sure if Racket has any up-to-date ORMs?) and static file handlers. I'd love help or feedback!

bliti 11y ago
From you experience, how is performance? what would you compare it too? The examples ae useful, thank you.
- nosefrog 11y ago
  I haven't written any big projects in Racket, so I can't say how it fares on real-world projects with real-world data, but here are the results for a very minimal Racket project using ApacheBench: ~ $ ab -n 100 -c 10 "http://localhost:8888/" http://localhost:8888/" This is ApacheBench, Version 2.3 <$Revision: 1638069 $> Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/ http://www.zeustech.net/ Licensed to The Apache Software Foundation, http://www.apache.org/ http://www.apache.org/ Benchmarking localhost (be patient).....done Server Software: Racket Server Hostname: localhost Server Port: 8888 Document Path: / Document Length: 89 bytes Concurrency Level: 10 Time taken for tests: 0.084 seconds Complete requests: 100 Failed requests: 0 Total transferred: 26800 bytes HTML transferred: 8900 bytes Requests per second: 1192.32 [#/sec] (mean) Time per request: 8.387 [ms] (mean) Time per request: 0.839 [ms] (mean, across all concurrent requests) Transfer rate: 312.05 [Kbytes/sec] received
  - SanFranManDan 11y ago
    Without a baseline comparison against other servers with same functionality on the same computer, these results mean nothing. For example here are benchmarks from Django's single-threaded debug webserver: Benchmarking 127.0.0.1 (be patient).....done Server Software: WSGIServer/0.1 Server Hostname: 127.0.0.1 Server Port: 8000 Document Path: / Document Length: 2 bytes Concurrency Level: 10 Time taken for tests: 0.100 seconds Complete requests: 100 Failed requests: 0 Total transferred: 16400 bytes HTML transferred: 200 bytes Requests per second: 998.90 [#/sec] (mean) Time per request: 10.011 [ms] (mean) Time per request: 1.001 [ms] (mean, across all concurrent requests) Transfer rate: 159.98 [Kbytes/sec] received Or Nginx returning the same thing: Benchmarking 127.0.0.1 (be patient).....done Server Software: nginx/1.6.2 Server Hostname: 127.0.0.1 Server Port: 9080 Document Path: /gangam Document Length: 14 bytes Concurrency Level: 10 Time taken for tests: 0.013 seconds Complete requests: 100 Failed requests: 0 Total transferred: 15600 bytes HTML transferred: 1400 bytes Requests per second: 7478.31 [#/sec] (mean) Time per request: 1.337 [ms] (mean) Time per request: 0.134 [ms] (mean, across all concurrent requests) Transfer rate: 1139.27 [Kbytes/sec] received

baldfat 11y ago

Just being exposed to Racket last month I was extremely surprised at how well it clicked with me as opposed to Haskel which I tried to learn for a few months on my own and just tried out SML and it moved to Racket. Can't put a finger on it but Racket just makes sense to me.

nosefrog 11y ago
I felt the same way, Racket is ridiculously fun to use! :)
snissn 11y ago
Have you tried python..? You might like it
- baldfat 11y ago
  I was trying to get exposure to functional programming. Yes I use Python (less and less) for many years, but I certainly wish there was a python when I was a teenagers.
- shriramkmurthi 11y ago
  Racket and Python aren't even remotely comparable as languages. Python is a far less sophisticated language with far richer libraries, and Racket is vice versa.

cneu 11y ago

Very nice proof of concept. Just a word of warning: In practice you want to sanitize your input. The code in "Serving static files" allows to break out of document-root with "..".

brlewis 11y ago
Have you tried to actually exploit that? I don't currently use Racket myself, but I would expect request-uri to prevent ".." and if it didn't surely url-path would. ; extract the URI from the request: (define uri (request-uri req)) ; extract the resource from the URI: (define resource (map path/param-path (url-path uri))) ; find the file location: (define file (string-append document-root "/" (string-join resource "/")))

59nadir 11y ago

Isn't your `any?` function actually `ormap`[0]? You should be able to do the same thing with: (ormap password-matches? line) 0 - http://docs.racket-lang.org/reference/pairs.html?q=ormap#%28def._%28%28lib._racket%2Fprivate%2Fmap..rkt%29._ormap%29%29 http://docs.racket-lang.org/reference/pairs.html?q=ormap#%28...

mattmight 11y ago
Yep! Jay McCarthy pointed this out, and I changed it. :)

octatoan 11y ago

Hijacking: Can anyone tell me how to make a Scribble website have CSS like in HTDP?

jeapostrophe 11y ago
Extra CSS can be added when running Scribble: http://docs.racket-lang.org/scribble/config-style.html?q=css http://docs.racket-lang.org/scribble/config-style.html?q=css