Rails Deployment with NginX
the quest for the perfect rails stack

Who Am I?
Stoyan Zhekov
➲
Bulgarian in Japan
➲
3 kids (boys)
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web: http://zhekov.net/
➲

Deploying Rails
What is deployment?
➲
Too many changes last years
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Money matters
➲
EngineYard: $299/mo per slice
●
RailsMachine: $245/mo + $60 setup
●

Basics are the same
Frontend web server
➲
processing static requests
●
Backend (application) server(s)
➲
processing dynamic requests
●
Database
➲

Basics are the same (2)
image by Ezra Zygmuntowicz

History Lesson
Apache + CGI
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Apache + FastCGI
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Lighttpd + FastCGI
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Lighttpd + SCGI
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Litespeed
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etc. etc. (mod_fcgi, mod_ruby)
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Mongrel
➲

Enter Mongrel

What is Mongrel?
image by Ezra Zygmuntowicz

What is Mongrel? (2)
flickr image

What is Mongrel? (3)
HTTP server and library by Zed Shaw
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Almost pure Ruby (HTTP parser in C)
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Modular = can have my own handlers
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Library = can have my own framework
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Merb: http://merb.rubyforge.org/
●
Ramaze: http://ramaze.rubyforge.org/
●

Why Mongrel (and HTTP)?
HTTP is well know protocol
➲
Mongrel is easy to setup
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Fast
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Easy management (monit)
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Scale easy
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Dynamic Requests
Mongrel != Rails
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Mongrel is Thread safe
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Rails isn't thread save (CGI.rb)
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Giant Mutex Lock around the Dispatcher
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Mongrel serving one request per time
➲

Mutex Lock around the Dispatcher
image by Ezra Zygmuntowicz

What to do?

Scale with processes
mongrel_cluster
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load balancer
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Load Balancer
pen (no SSL)
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pound (restart to reload the config)
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balance
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HAproxy
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LiteSpeed Load Balancer ($1299)
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The common problem?
No static file serving
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Load is shifting to the backends (bad)
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Static Requests
JavaScript – bigger and bigger (AJAX)
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Multimedia – video, images
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Rails caching - .html
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Distributed assets - assets%i.dot.com
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Frontend Web Server
Apache – not enough RAM in VPS
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Lighttpd – memory leak under heavy load
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Litespeed – 300 simultaneous req limit
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NginX: from Russia with love
Name: nginx [engine x]
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HTTP server and IMAP/POP3/SMTP proxy
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20% of russian sites
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fastmail.fm
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EngineYard
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Problems?
One man project
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Do you read/speak russian? - I do ;)
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No CGI support
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Why NginX?
Good performance
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Small memory footprint (VPS)
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No memory leaks in the proxy
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name- and IP-based virtual servers
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PUT, DELETE, MKCOL, COPY and MOVE
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Modular
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FLV streaming
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Good Performance
Serious Web servers use event loops
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http://www.kegel.com/c10k.html
●
Optimized for every OS (async)
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BSD – kqueue
●
Linux 2.6 – epool
●
Solaris 10 – EventPorts (Joyent.com)
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High availability
Management by unix signals
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kill -HUP – reload the config
●
kill -USR2 – BINARY RELOAD
●

Coding style
if (m[1] == 'O') {
if (m[0] == 'P' && m[2] == 'S' && m[3] ==
'T') {
r->method = NGX_HTTP_POST;
break;
}
if (m[0] == 'C' && m[2] == 'P' && m[3] ==
'Y') {
r->method = NGX_HTTP_COPY;
break;
}
...

NginX Installation
Two versions: 0.5.x (stable) and 0.6.x
(devel)
(Debian/Ubuntu)
# apt-get install libssl-dev
http://zhware.net/code/shell/mk_nginx.sh.txt

NginX Configuration
Ezra Zygmuntowicz (merb, BackgroundDRb):
http://brainspl.at/nginx.conf.txt
http://pastie.caboo.se/84928
# gem install nginx_config_generator
# generate_nginx_config –example > config.yml
# generate_nginx_config config.yml nginx.conf

Config: OS tuning
user www-data;
worker_processes 1;
events {
worker_connections 1024;
use epoll;
}

Config: HTTP block
http {
include conf/mime.types;
include conf/optimize.conf;
upstream mybackends {
server b1.example.com weight=5;
server b2.example.com:8080;
server unix:/tmp/backend3;
}
server {
...
}

Config: server block
server {
listen 80;
name s1.example.com;
location / {
}
}
server {
listen 80;
name s2.example.com;
...
}

Config: location blog
location / {
...
proxy_pass http://mybackends;
...
}

Interesting features
Virtual SSI
➲
<!--# include virtual=”/foo” -->
●
Mirror on demand
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memcached module
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NginX Rails config
location / {
# static files
if (-f $request_filename) {
break;
}
# rails caching
if (-f $request_filename.html) {
rewrite (.*) $1.html break;
}
if (!-f $request_filename) {
proxy_pass http://mongrel;
break;
}
}

Links
english: http://nginx.net/
➲
wiki: http://wiki.codemongers.com/
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my notes: http://wiki.zhekov.net/nginx
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links: http://del.icio.us/zh/nginx
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chat: #nginx on FreeNode,
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http://www.lingr.com/room/nginx/

What else?
Combinations
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nginx + Litespeed backends
●
Backend optimizations
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Swiftiply Proxy: http://swiftiply.swiftcore.org/
●
Evented Mongrel (eventmachine)
●
Edge Side Includes (ESI):http://www.esi.org/
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Merb instead of Rails
➲

Questions?