Improving Your Heroku App Performance with Asset CDN and Unicorn

Optimizing rails applications’ performance

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Friday, January 11, 13

mailto:[email protected]


Question

Does anyone know what

f5dd

is?


What *is Preso is NOT

• not a coding demo or tutorial (strangely)

• not a best practices showcase


What *is Preso IS

• tips and tricks on tuning rails application

• personal experience


DisclaimerThere are many other ways to improve app’s performance:

•database performance (indexes, N+1, slow queries)•caching•background processing•changing interpreter, GC•conditional asset loading, etc•removing cruft!

Try them first!


*is Presentation - Two Parts

• CDN Asset Host using aws*

• unicorn web server*

* Both approaches were tested on heroku, but must work with other hosting solutions


Sample App


NewRelic Monitoring

average load time for mobile traffic only, includes iframed ads


Heroku Dyno Operation


Step 1 - Rack::Cache

Serving assets from rack::cache is faster, and frees up app instance to serve more requests


Static Asset Caching# Gemfilegem 'dalli'

# config/application.rbconfig.cache_store = :dalli_store

# config/environments/production.rbconfig.action_dispatch.rack_cache = { :metastore => Dalli::Client.new, :entitystore => 'file:tmp/cache/rack/body', :allow_reload => false}config.serve_static_assets = trueconfig.assets.digest = true

config.action_controller.perform_caching = true# provision Memcache addon on Heroku


A2er Deploymentshould see entries like this in your log

cache: [GET /assets/application-c0747cab950350f59304a3815f980622.css] miss, storecache: [GET /assets/application-032691d4988a7003c42a10995819a0ce.js] miss, storecache: [GET /assets/s_code.js] miss, store

cache: [GET /assets/application-c0747cab950350f59304a3815f980622.css] freshcache: [GET /assets/application-032691d4988a7003c42a10995819a0ce.js] freshcache: [GET /assets/s_code.js] fresh


Using Rack::Cache Effect

down from 4.91 / 201 / 2.29 before the change -- not bad for 8 lines of code!


Step 2 - S3 bucket for assets

heroku instance has more time to serve application code because all assets are served from aws s3


S3 Bucket for Assets# Gemfilegem "asset_sync" # will push compiled assets into CDN

# Command lineheroku config:add FOG_PROVIDER=AWS \ AWS_ACCESS_KEY_ID=xxx \ AWS_SECRET_ACCESS_KEY=yyy

heroku config:add FOG_DIRECTORY=yourappname-assets

# config/environments/production.rbconfig.action_controller.asset_host = "//#{ENV['FOG_DIRECTORY']}.s3.amazonaws.com"

# make sure to use AssetTagHelper methods (like image_tag)# to ensure assets are properly referenced


Now, on git push heroku

assets are automatically synced to s3 anytime ON rake assets:precompile


S3 Bucket effect

down from 4.45 / 179 / 2.43 before the change -- even better!


Step 3 - AWS CloudFront


CloudFront Effect

down from 3.85 / 179 / 2.19 before the change -- Awesome!


Loading Single 5le$ time curl http://careersingear.mobi/assets/application-bdb77a926724ccc3c20b923ab168d89d.js

real 0m0.896suser 0m0.008ssys 0m0.016s

----------------

$ time curl http://d3kd72psxbec02.cloudfront.net/assets/application-bdb77a926724ccc3c20b923ab168d89d.js

real 0m0.293suser 0m0.006ssys 0m0.010s

getting a single application.js file from cloud front is 3x faster


http://careersingear.mobi/assets/application-bdb77a926724ccc3c20b923ab168d89d.js




http://d3kd72psxbec02.cloudfront.net/assets/application-bdb77a926724ccc3c20b923ab168d89d.js




WebPageTest ResultsBefore


WebPageTest Results A2er


Meet Unicorn• HTTp server for Ruby

• Starts one master process

• forks worker processes

• workers handle requests

• master returns

• one port, several concurrent requests


Server Setup

classic setup nginx -> smart balancer -> pool of mongrels

Unicorn setup nginx -> unix domain socket -> unicorn workers (os handles load balancing)


Unicorn for Rails App# Gemfilegem 'unicorn'

# Procfileweb: bundle exec unicorn -p $PORT -c ./config/unicorn.rb

# config/application.rbconfig.logger = Logger.new(STDOUT)

# also, add config/unicorn.rb


Unicorn for Rails App# config/unicorn.rbworker_processes 3timeout 30preload_app true before_fork do |server, worker| if defined?(ActiveRecord::Base) ActiveRecord::Base.connection.disconnect! Rails.logger.info('Disconnected from ActiveRecord') end

if defined?(Resque) Resque.redis.quit Rails.logger.info('Disconnected from Redis') end

end after_fork do |server, worker| if defined?(ActiveRecord::Base) ActiveRecord::Base.establish_connection Rails.logger.info('Connected to ActiveRecord') end if defined?(Resque) Resque.redis = ENV["REDISTOGO_URL"] Rails.logger.info('Connected to Redis') endend


A2er Implementing Unicorn

down from 3.64 / 46.7 / 1.17 before the change -- good, but also...


Better Concurrency Handlingrequire 'typhoeus'require "benchmark"

URL = "http://careersingear.mobi"HYDRA = Typhoeus::Hydra.new(max_concurrency: 20)

1000.times do request = Typhoeus::Request.new(URL, method: :get, timeout: 10000) request.on_complete do |response| puts response.code end HYDRA.queue(request)end

Benchmark.bm(7) do |x| x.report("first:") { HYDRA.run }end

# using thin# user system total real# 1.030000 0.380000 1.410000 ( 16.713791)

# using unicorn# user system total real# 1.050000 0.390000 1.440000 ( 7.843766)


http://careersingear.mobi

http://careersingear.mobi

And ...

my app can process six concurrent requests on two heroku dynos


Riding Unicorn


To Conclude

• implemented asset cdn

• configured unicorn

• brought down average end user load time from almost 5 sec to 3.5 sec

• app can serve more requests faster and for less $$$



Creditsdefunkt, unicorn! https://github.com/blog/517-unicorn

heroku dev center, using rack::cache with memcached in rails 3.1+ https://devcenter.heroku.com/articles/

rack-cache-memcached-rails31

Rice, david, using a cdn asset host with rails 3.1 https://devcenter.heroku.com/articles/cdn-asset-

host-rails31

Sikkes, Michael, Complete Guide to serving your Rails assets over S3 with asset_sync http://blog.firmhouse.com/

complete-guide-to-serving-your-rails-assets-over-s3-with-asset_sync

van roijen, michael, more concurrency on a single heroku dyno with the new celadon cedar stack http://

michaelvanrooijen.com/articles/2011/06/01-more-concurrency-on-a-single-heroku-dyno-

with-the-new-celadon-cedar-stack/


https://github.com/blog/517-unicorn

https://github.com/blog/517-unicorn

https://devcenter.heroku.com/articles/rack-cache-memcached-rails31




https://devcenter.heroku.com/articles/cdn-asset-host-rails31




http://blog.firmhouse.com/complete-guide-to-serving-your-rails-assets-over-s3-with-asset_sync






http://michaelvanrooijen.com/articles/2011/06/01-more-concurrency-on-a-single-heroku-dyno-with-the-new-celadon-cedar-stack/






Q & AThis presentation can be found on github github.com/semmin/asset-cdn-and-unicorn-preso

twitter: @status_200

Email: [email protected]

Questions?


https://github.com/semmin/asset-cdn-and-unicorn-preso

https://github.com/semmin/asset-cdn-and-unicorn-preso



Documents

Improving Your Heroku App Performance with Asset CDN and Unicorn