A Scalable Rails App Deployed in 60 Seconds

A Scalable Rails app Deployed in 60

secondsA love affair with Rails & Heroku.

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Ben Scheirman

• Director of Development at ChaiONE

• Microsoft MVP, ASP Insider

• Certified ScrumMaster

• Former .NET Ninja, now Rails/iPhone aficionado

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Ben Scheirman

• ...not affiliated with Heroku

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So you have a fantastic app?

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Now deploy it...

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Shared HostingVirtual Dedicated

Dedicated6

Shared Hosting

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Shared Hosting

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Shared Hosting

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Shared Hosting

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Shared Hosting

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Shared Hosting

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Virtual Dedicated

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Virtual Dedicated

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Dedicated

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Scale

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x 1,000?11

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x 10,000?12

writes

reads

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x 1,000,000?

writes

reads

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ScaleOn-Demand

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0

100

200

300

400

12 AM 3AM 6AM 9AM 12PM 3PM 6PM 9PM 12AM

# Users by time of day

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0

100

200

300

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0

100

200

300

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Only need massive scale from 9am - 9pm

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225

450

675

900

Mar 1 Mar 15 Apr 1 Apr 15 May 1 May 15 Jun 1 Jun 2

Expected Users For PR Campaign

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0

225

450

675

900

Mar 1 Mar 15 Apr 1 Apr 15 May 1 May 15 Jun 1 Jun 2

Expected Users For PR Campaign

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Wouldn’t this be magical?

SCALE

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Forget about servers19

Awesome Shredder Art by Dan Barret

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Awesome Shredder Art by Dan Barret

gem install heroku

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• Platform as a service for Rack-based apps

• Scale easily

•Great workflow

• Free to start / Friendly Pricing

• Complete command-line API

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git initgit add .git commit -m “My First Commit”heroku creategit push heroku master

Deploy a rails app in 5 steps

Creating morning-summer-18..... doneCreated http://morning-summer-18.heroku.com/ | [email protected]:morning-summer-18.git

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http://morning-summer-18.heroku.com


mailto:[email protected]


git initgit add .git commit -m “My First Commit”heroku creategit push heroku master

Deploy a rails app in 5 steps

LET THAT SOAK IN...

Creating morning-summer-18..... doneCreated http://morning-summer-18.heroku.com/ | [email protected]:morning-summer-18.git

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Using git for deployment is f***ing GENIUS

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• Amazon Web Services

• Caching w/ Varnish

• Debian Linux

• Erlang Routing Mesh

• Nginx

• PostgreSQL

Technology

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How Heroku Scales

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How Heroku Scalesor WTF is a Dyno?

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How Heroku Scales

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How Heroku Scales

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How Heroku Scales

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• Increasing response times

• “Backlog Too Deep” Error

When to add dynos

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• New Relic RPM

• Apache Bench

Always Measure

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• Multiple Heroku apps for Test, Staging, Production

• Learn the awesome-ness of Taps

• Heroku logs

• Heroku Console

• Useful addons: New Relic, Exceptional

Heroku Tips

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Backups

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Coping with the Free Single Bundle task :backup do bundle_name = "my-backup" heroku_app = ENV['app'] def wait_for_response_text(text) heroku_app = ENV['app'] #lame, I know begin puts "." bundles = `heroku bundles --app #{heroku_app}` end while bundles.match(text).nil? end #check for existing bundle bundles = `heroku bundles --app #{heroku_app}` unless bundles.match /has no bundles/ `heroku bundles:destroy #{bundle_name} --app #{heroku_app}` wait_for_response_text 'has no bundles' end puts "Capture bundle #{bundle_name}..." `heroku bundles:capture #{bundle_name} --app #{heroku_app}` wait_for_response_text "complete" puts "Downloading bundle..." `heroku bundles:download #{bundle_name} --app #{heroku_app}` timestamp = `date -u '+%Y-%m-%d-%H-%M'`.chomp new_path = "backups/#{heroku_app}-#{timestamp}.tar.gz" mkdir "backups" unless File.exists? "backups" `mv #{heroku_app}.tar.gz #{new_path}` puts "Bundle saved to #{new_path}" end end

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One-button Deployments task :deploy do heroku_app = ENV['app'] heroku_config = Hash.new Rake::Task["heroku:backup"].invoke puts "Turning maintenance on..." puts "** " + `heroku maintenance:on --app #{heroku_app}` sleep 15 #maintenance mode causes your slug to be recompiled puts "Pushing changes to heroku..." puts "** " + `git push #{git_remotes[heroku_app]} master` puts "Migrating heroku databases..." puts "** " + `heroku rake db:migrate --app #{heroku_app}` puts "Setting up config variables..." heroku_config.each_pair do |k, v| puts "** " + `heroku config:add #{k.to_s.upcase}=#{v}` end puts "Turning maintenance mode off" puts "** " + `heroku maintenance:off --app #{heroku_app}` puts "DEPLOYMENT DONE!" end

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Delayed Jobs

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Delayed Jobs

def send_bulk_emails

BulkEmailSender.send_a_tonflash[:notice] => "Ok we sent them"

end

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Delayed Jobs


BulkEmailSender.send_a_tonflash[:notice] => "Ok we sent them"

end


BulkEmailSender.send_later(:send_a_ton)flash[:notice] => "Ok we sent them"

end

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Delayed Jobs

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Delayed Jobs

> gem install delayed_job> rails g delayed_job > rake db:migrate

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Delayed Jobs

> gem install delayed_job> rails g delayed_job > rake db:migrate

> heroku workers 1 simple-snow-68 now running 1 worker

> heroku workers +1 simple-snow-68 now running 2 workers

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Delayed Jobs

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Delayed Jobs

$0.05 per hour / worker(even when it's not processing Jobs)

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Delayed Jobs

$0.05 per hour / worker(even when it's not processing Jobs)

http://github.com/pedro/delayed_job/commit/09d7657e1fc7d25072e6c5e73ede20d6e1185eac

http://bit.ly/9Qokff

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Delayed JobsPedro's Fork / auto-scale branch

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Delayed JobsPedro's Fork / auto-scale branch

//lib/delayed/job.rbdef after_createManager.scale_up if self.class.auto_scale && Manager.qty == 0

end

//lib/delayed/worker.rbManager.scale_down if count.zero? && Job.auto_scale && Job.count == 0

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• Read-only file system

• some gems don’t work

• File uploads?

• Temp Directory

• SSL, memcached, Full-text-search expensive

• Bound-by Amazon’s SLA

Gotchas

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contact = {

! :blog => http://flux88.com,!! :twitter => @subdigital,!! :email => [email protected]

}

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http://flux88.com

http://flux88.com



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