Eitaro Fukamachi presented on the Woo web server project for Common Lisp. Woo is an event-driven, multithreaded web server built on top of fast-http and QURI for fast HTTP and URI parsing. It aims to be the fastest web server in Common Lisp. Key aspects that contribute to its speed include using the libev event library, avoiding bottlenecks from HTTP and URI parsing, and having a multithreaded event-driven architecture. Future work includes improving multithreading performance using Legion and adding SSL and HTTP/2 support.

1. Woo:
Writing a fast web server
Lisp Meetup #25 Eitaro Fukamachi

2. Thank you for coming.

3. I’m Eitaro Fukamachi
@nitro_idiot fukamachi

4. Looking for a Common Lisp job?
We’re hiring!
https://www.wantedly.com/projects/15144

5. (and 'web-application-engineer
'common-lisper)

6. (and 'web-application-engineer
'common-lisper)

7. (and 'web-application-engineer
'common-lisper)
server :(

8. Woo

9. Woo = Ultra Monster??
http://ultra.wikia.com/wiki/Woo_(kaiju)

10. Woo = Ultra Monster??

11. Woo = Ultra Monster??

12. • Web server for Clack applications
• HTTP/1.x
• Built on top of fast-http, QURI, libev
• Similar to Wookie, but even faster
Woo

13. Woo
https://github.com/fukamachi/woo#benchmarks

14. Woo
(woo:run
(lambda (env)
‘(200 (:content-type “text/plain”) (“Hello, World”))))
(clack:clackup
(lambda (env)
‘(200 (:content-type “text/plain”) (“Hello, World”)))
:server :woo)
Run with Clack

15. Let me tell
why I could make it so fast.

16. 3 difficult things
in web servers

17. 3 difficult things
• Network I/O is the largest bottleneck
• Need to handle a vast amount of requests
at once
• Need to handle various HTTP clients
(fast / slow / unstable)

18. Why fast?
1. Better architecture
2. The libev event library
3. Fast HTTP & URI parsing

19. Reason 1:
Better architecture

20. 2 architectures:
Prefork vs Event-driven

21. Prefork
Worker
thread
Worker
thread
Worker
thread
master thread
Requests
accept connections
Responses
• Simple
• Fast for little
simultaneous
connections
• ex) Hunchentoot,
Unicorn, Apache

22. Prefork
Worker
thread
Worker
thread
Worker
thread
master thread
Requests
accept connections
Responses • Slow client can
cause performance
issue.
• like Mobile users
• Slowloris attack
blocking!
･･･
Problem

23. Event-driven
• Handle many
clients at the same
time
• Asnyc ACCEPT/
READ/WRITE
• ex) Woo, Wookie,
Tornado, nginxServer process
(single-threaded)
Event loop

24. Event-driven
• Single-threaded
Problem
Server process
(single-threaded)
Event loop

25. Woo took another way:
Multithreaded event-driven

26. Multithreaded event-driven
Server process
Event loop
listen on the same file descriptor
Server process
Event loop
Server process
Event loop

27. Reason 2:
The libev event library

28. libev
• Wrapper of epoll, kqueue, POSIX select, poll
• Thin
• Fast
• Poor Windows support
• I don’t think people run a web server on
Windows

29. First choice: cl-async
• Wookie built on top of cl-async
• cl-async was used to use libevent2
• Node.js uses libuv
• libevent2 might be the bottleneck
• cl-async has moved to libuv now

30. Reason 3:
Fast HTTP & URI parsing

31. HTTP parsing can be a bottleneck
• Wookie's largest bottleneck is HTTP parsing
• http-parse (uses regular expression)
• fast-http (byte to byte parser)
• 135 times faster than http-parse
• http://slideshare.net/fukamachi/writing-
a-fast-http-parser

32. URI parsing can be a bottleneck
• Wookie & Woo parses URI for dispatching
• PURI is *not really* fast
• QURI
• 6 times faster than PURI

33. Goal

34. Goal: What is fast enough?
• The initial goal was “Beating Node.js”
• Done
• Being the fastest web server in Common
Lisp
• Done

35. Got a great Pull Request

36. Future tasks

37. Future tasks
• Multithread performance
• SSL support
• HTTP/2 support

38. Multithread performance

39. Multithread performance
• Working in progress
• Legion

40. Status

41. Photo by Robert Couse-Baker licensed under the CC BY 2.0

42. Photo by Robert Couse-Baker licensed under the CC BY 2.0
Status
• Still alpha version
• Use at your own risk
• Tested with SBCL on Linux/Mac OS
• The latest bug:
• Cannot run in Americas (TZ problem)

43. Thanks.

44. EITARO FUKAMACHI
8arrow.org
@nitro_idiot fukamachi