Nick Sieger

RailsConf: Ezra Zygmuntowicz - Rails Deployment

Posted by Nick Sieger Sat, 24 Jun 2006 19:18:00 GMT

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.