RailsConf: Ezra Zygmuntowicz - Rails Deployment

Nick Sieger — Sat, 24 Jun 2006 19:18:00 +0000

Ezra: Programming in Ruby for 3 years, Rails for 2. Just another Ruby hacker, he says. Right!

Yakima Herald

http://yakimaherald.com – Local newspaper website
CMS
Lots of non-SQL content
Classified and obituary workflow
Internal credit card transaction

Data Aggregation

Mysql
XML feeds from AP
RSS and Atom feeds from parent newspaper
Proprietary database for articles
- Yucky Vendorscript
- Crusty OS 9 server!
- Wrote DSL to emit script over a socket to remote machine

Deployment

Apache? Seems to be the industry standard…

class ApacheWithFCGI < ActiveRecord::Base
  has_many :random_500_errors
end

Lighttpd
- Better FCGI support
- More stable
Switched to standalone, external FCGIs with capistrano spinner/spawner/reaper tasks, and finally got stable.

Tuning

Cache, cache, cache
Got RAM?
Hot spot/profiling/benchmarking
Use httperf not ab
See Zed Shaw’s rant on statistics (Programmers Need To Learn Statistics Or I Will Kill Them All)

Shared hosting

Apache with ProxyPass/ProxyPassReverse talking to multiple lighty instances is about as good as it gets.
But let’s face it…shared hosting + Rails suck.
Only as reliable as the worst application on the server
Not always good neighbors
Resource constraints
Free-for-all

Ezra recommends a Xen VPS for Rails deployment. I’ve followed his advice; this blog is hosted on a Xen VPS at http://rimuhosting.com.

Deployment models

Starting point, web, app and db on the same server.
Next, move database to a separate server. Use the more powerful hardware to the db.
Third, split each role to a separate server. But now you need an NFS to serve static and cached contents. Ezra states you can go a long way with this setup

class FutureOfRailsDeployment < ActiveRecord::Base
  belongs_to :mongrel
end

Mongrel

Speaks plain old HTTP, so you can take advantage of existing tools for load balancing, proxying or caching
You can use frontends: Pound, Pen, Balance, Haproxy, Lighttpd (although mod_proxy needs to be fixed), or Apache 2.2 modproxybalancer
Mongrel cluster gem allows easy management of multiple mongrel processes. It’s straightforward to integrate with capistrano too.

Engine Yard

Ezra describes a new hosting service he’s been working on that will give you a greatly simplified but powerful and performant hosting environment for your Rails applications, including a web admin console and deployment directly from SVN revisions and tags.

Go to Engine Yard for a beta signup email now!

BackgroundDrb

Distributed Ruby server that manages long runnng tasks.
Uses a MiddleMan proxy/stub class that allows the Rails process to connect to the background server.
Can use it as a worker queue, (e.g. for sending email) or as a distributed memory cache.
You can even query for progress on the background workers and push the result all the way to the browser with an ajax progress bar.
The code for BackgroundDrb looks really clean! Go to http://backgroundrb.rubyforge.org/ for the nitty gritty.

Nick Sieger: RailsConf: Ezra Zygmuntowicz - Rails Deployment