Learn how realestate.com.au scales through horizontal/vertical scaling, and judicious use of HTTP caching and CDNs.

1. Scaling @ REA
Geoffrey Giesemann

3. scaling ain't easy
no silver bullet, no secret sauce

4. but Rails *can*
scale!
our first ever Rails app

6. do we need to scale?
$ siege -t 60s list_of_urls.txt
** SIEGE 2.72
** Preparing 15 concurrent users for battle.
The server is now under siege...
pay attention to:
● transaction rate
● throughput
● concurrency

7. Vertical Scalin'
aka more RAMs plz

10. HTTP Caching

11. HTTP Caching 101
Expiration:
Cache-Control: public, max-age=60
Validation:
ETag: 1234567890abcdef
Last-Modified: Thu, 30 Aug 2012 14:03:49 EST

12. realestate.com.au/buy
Empty cache:
Non-empty cache:

13. ActionController::ConditionalGet
class DooHickeyController < ApplicationController
def show_something
expires_in 1.day
@doo_hickey = DooHickey.find(params[:id])
if stale?(:etag => @doo_hickey,
:last_modified => @doo_hickey.updated_at
)
@doo_hickories = @doo_hickey.children # expensive
repond_to do |format|
# etc...
end
end
end
end

14. Content Distribution
Networks
(and S3 asset hosting)

15. getting out of the static asset
hosting business
S3 is an infinite disk that is plugged in to the
internet
can pretend you're not on S3 if you set up DNS
appropriately
currently migrating all property images on to S3

16. you can do with with Rails too!
use jammit-s3 to compile/load your assets into
S3
paperclip will let you upload into S3
dragonfly support resizing with S3 caching

17. scaling lessons learned
simpler is easier to scale than complex
particularly if you can separate the reading/writing parts of
your app
when in doubt - test
you do TDD right? scaling shouldn't be different

18. scaling lessons learned
the fastest request is the one you never make
CDNs are awesome
provided their edge nodes match the distribution of your
users

19. the cloud is coming to AU
rackspace is building a DC in Sydney
opening ~late 2012
CDN and Route53 available in Sydney
more on the way?

20. Questions?