4. What is Google App Engine?
• A cloud-computing platform
• Run your web apps on Google’s infrastructure
• Platform as a Services (PaaS)
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5. App Engine Architecture
Incoming Requests
Load App Engine App Engine App Engine
Balancer Front End Front End Front End
AppServer AppServer AppServer
Other Google
AppServer Infrastructure
API Layer - Bigtable
- Google Accounts
- Memcache
App App App
- Image manipulation
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7. Quotas and Billing
Resource Provided Free Additional Cost
CPU 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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8. Ruby on App Engine
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9. Apps run on JRuby
• Fast and portable
• A wealth of integration options
• Supported App Engine Java APIs
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10. Small & Modular Frameworks
• Rack
• Sinatra
• Merb/Rails3*
• Duby
* Currently unreleased
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11. DataMapper for Persistence
• Schema defined in your model
• Extensions for validations, AR finders & more
• Works with existing dm-appengine adapter
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12. Easy to Install
sudo gem install google-appengine
Everything you need installs as gems
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16. Demo
run lambda { |env| [200, {}, 'Hello'] }
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17. Current Issues with JRuby on App Engine
• Several seconds to “spin-up” a new JRuby instance
• Some gems still need their extensions ported to Java
• Not officially supported
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19. Duby’s not Ruby
• Statically typed
• No Duby runtime
• Uses Java’s type system
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20. Duby has Ruby-inspired Syntax
def fib(a:int)
if a < 2
a
else
fib(a - 1) + fib(a - 2)
end
end
puts fib 10
Saturday, November 21, 2009
21. // Generated from examples/Test.duby
public class Test extends java.lang.Object {
public static void main(String[] argv) {
System.out.println(Test.fib(10));
}
public static int fib(int a) {
return (a < 2) ?
(a) :
((Test.fib((a - 1)) + Test.fib((a - 2))));
}
}
Saturday, November 21, 2009
22. A Simple Duby App
import javax.servlet.http.HttpServlet
import com.google.appengine.ext.duby.db.Model
class Post < Model
def initialize; end
property title, String
property body, Text
end
class DubyApp < HttpServlet
def_edb(list, 'com/ribrdb/list.dhtml')
def doGet(request, response)
@posts = Post.all.run
response.getWriter.write(list)
end
def doPost(request, response)
post = Post.new
post.title = request.getParameter('title')
post.body = Text.new(request.getParameter('body'))
post.save
doGet(request, response)
end
end
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23. A Simple Duby App
import javax.servlet.http.HttpServlet
import com.google.appengine.ext.duby.db.Model
class Post < Model
def initialize; end
property title, String
property body, Text
end Types
class DubyApp < HttpServlet inferred from parent
def_edb(list, 'com/ribrdb/list.dhtml')
class
def doGet(request, response)
@posts = Post.all.run
response.getWriter.write(list)
end
def doPost(request, response)
post = Post.new
post.title = request.getParameter('title')
post.body = Text.new(request.getParameter('body'))
post.save
doGet(request, response)
end
end
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24. A Simple Duby App
import javax.servlet.http.HttpServlet
import com.google.appengine.ext.duby.db.Model
class Post < Model
def initialize; end
property title, String
property body, Text
end
Plugins
class DubyApp < HttpServlet
def_edb(list, 'com/ribrdb/list.dhtml')
def doGet(request, response)
@posts = Post.all.run
response.getWriter.write(list)
end
def doPost(request, response)
post = Post.new
post.title = request.getParameter('title')
post.body = Text.new(request.getParameter('body'))
post.save
doGet(request, response)
end
end
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25. Duby Supports Plugins
Only form of metaprogramming (for now)
require 'erb'
Duby::AST.defmacro('def_edb') do |duby, fcall, p|
name = fcall.args_node.get(0).name
path = fcall.args_node.get(1).value
erb = ERB::Compiler.new(nil)
...
src = erb.compile(IO.read(path))
duby.eval(src, p, “(edb)”)
end
Saturday, November 21, 2009
26. Duby Can Use erb Templates
<title>Posts</title>
<body>
<h1>All Posts:</h1>
<% for post in @posts %>
<h2><%= post.title %></h2>
<p><%= post.body.getValue %></p>
<% end %>
<hr>
<h1>New Post:</h1>
<form method=post>
Title: <input type=text name=title><br>
Body: <textarea name=body></textarea><br>
<input type=submit>
</form>
</body>
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27. More to Come
• Open classes
• Mix ins
• Blocks
• More
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28. Resources
• Ryan Brown, ribrdb@google.com
John Woodell, woodie@google.com
• Google App Engine for JRuby
– http://code.google.com/p/appengine-jruby/
• Google Group
– http://groups.google.com/group/appengine-jruby
• Blog: JRuby on App Engine Blog
– http://jruby-appengine.blogspot.com/
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