JRuby on App Engine Run Ruby apps on Google Servers, with access to first-class Java APIs 2010-05-06

1. Sunday, May 9, 2010

2. JRuby on App Engine
Run Ruby apps on Google Servers,
with access to first-class Java APIs
John Woodell
May 6, 2010
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3. Google App Engine
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4. Key Features
• No need to install or maintain your own stack
• Use Google scalable services via standard APIs
• Built-in application management console
• Google does the scaling for you
• Pay-as-you-go, with free quota to get started
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5. Key Limitations
• No native code
• No threads or sockets
• No writing to the filesystem
• No relational database
• No more than 30 seconds per request
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6. Dev AppServer
• Local implementation of services
– LRU memcache
– Disk-backed datastore
– HttpClient-backed URLFetch
• Emulates the production environment
– Sandbox restrictions may be inconsistent,
so run tests on production servers as well
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7. Deployment
• Your app lives at
– <app_id>.appspot.com, or
– Custom domain with Google Apps
• Deploying uploads
– Static files
– Resource files
– Other metadata (datastore indexes, cron jobs)
• Admin Console
– dashboards
– manage multiple versions
– view logs
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8. Quotas and Billing
Resource Provided Free Additional Cost
CPU time 6.5 hours/day $0.10/hour
Bandwidth In 1GByte/day $0.10/GByte
Bandwidth Out 1GByte/day $0.12/GByte
Stored Data 1 GB $0.005/GB-day
Emails sent 2000/day to users $0.0001/email
50000/day to admins
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9. App Engine Product Roadmap
• SSL for third-party domains
• Background servers capable of running for longer than 30s
• Ability to reserve instances to reduce application loading overhead
• Ability to select different availability vs. latency options for Datastore
• Support for mapping operations across datasets
• Datastore dump and restore facility
• Raise request/response size limits for some APIs
• Improved monitoring and alerting of application serving
• Support for Browser Push (Comet) communication
• Built-in support for OAuth & OpenID
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10. JRuby on App Engine
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11. Rails Deployment History
• 2004 - FastCGI on Apache or Lighttpd
“a rocket that sometimes blows up in strange ways”
• 2006 - Mongrel clusters behind Apache mod_proxy
“high throughput, but requires multiple moving parts”
• 2008 - Phusion Passenger on Apache
“simply upload files, rack-based, REE/COW”
• 2010 - Running in a servlet container with JRuby-Rack
“powerful/portable/scalable, rack-based, JRuby”
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12. Benefits of JRuby
• Outperforms MRI in many cases... 2x to 10x
• Gem extensions written in Java (no more segfaults)
• A wealth of integration options and first-class Java APIs
• Spin-up new instances quickly using Duby (or Java) servlets
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13. App Engine JRuby Milestones
• 2009-04-08 @olabini publishes blog post on YARBL
• 2009-05-06 RailsConf
• 2009-11-02 0.0.5 bundler, precompilation, Duby
• 2009-11-20 RubyConf
• 2009-12-02 0.0.6 Rails 3.0.pre primer & image demos
• 2009-12-27 @urekat publishes Rails 2.3.5 patches
• 2010-01-21 0.0.8 Rails 2.3.5 Primer for DM & TinyDS
• 2010-01-26 0.0.9 Mechanize and Hpricot demos
• 2010-02-19 @carlhuda publishes bundler08
• 2010-02-27 0.0.10 ActionMailer demos
• 2010-04-08 0.0.11 deferred dispatcher (early look)
• 2010-05-06 0.0.12 JRuby 1.5 & OpenSSL 0.7
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14. Current Issues with JRuby on App Engine
• Several seconds to “spin-up” a new JRuby instance
• Some gems may need their extensions ported to Java
• Not officially supported , but you have all that you need
+
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15. Install it Now
sudo gem install google-appengine
Everything you need installs as gems
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16. App Engine Gems
• Development Gems
– appengine-sdk
– appengine-jruby-jars
– appengine-rack
– appengine-tools . . . dev_appserver.rb & appcfg.rb
• Runtime Gems
– appengine-rack . . . . rack & jruby-rack
– appengine-apis
• Related Gems
– dm-appengine
– rails_appengine
– rails_dm_datastore
– rails_tiny_ds
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17. App Engine JRuby APIs
• AppEngine::Users
• AppEngine::Datastore
• AppEngine::Memcache
• AppEngine::Mail
• AppEngine::URLFetch
• AppEngine::Images
• AppEngine::Logger
• AppEngine::XMPP
• AppEngine::Labs::TaskQueue
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18. Users API
• Existing User Account
• Restrict your app to a domain
map '/src' do
use AppEngine::Rack::AdminRequired
use AppEngine::Rack::SSLRequired
run ActionController::Dispatcher.new
end
map '/' do
run ActionController::Dispatcher.new
end
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19. Datastore API + DataMapper
# Comparisons you’d expect
Zoo.first(:name => 'Galveston')
# The 'gt/lt' means greater/less-than.
Person.all(:age.gt => 30)
Person.all(:age.lt => 40)
# The 'gte/lte' means greather/less-than-or-equal-to.
Person.all(:age.gte => 30)
Person.all(:age.lte => 40)
# The value of a pair is an Array
Person.all(:name => 'Sam', :id => [ 1, 2, 3, 4, 5 ])
Person.all(:name => [ 'bob', 'rick', 'steve' ])
# Ordering
Person.all(:order => [ :age.desc ])
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20. Memcache API
• No configuration required
• Same API as Ruby-Memcache
• Keys can be any Symbol or String
• Can store any Marshalable or Serializable object
cache = AppEngine::Memcache.new
cache.set_many({:a => 1, :foo => 1..5})
a, foo = cache.get(:a, :foo)
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21. URL Fetch API
• Drop-in replacement for Net::HTTP
AppEngine::URLFetch.fetch(url, options={})
:method
:payload
:headers
:allow_truncated
:follow_redirects
:deadline
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22. Resources
• John Woodell, @johnwoodell
• Blog
– http://jruby-appengine.blogspot.com/
• Code Site
– http://code.google.com/p/appengine-jruby/
• Google Group
– http://groups.google.com/group/appengine-jruby
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