Talk about Heroku from WJAX 2013

1. Eberhard Wolff
Freelance Consultant / Trainer
Head Technology Advisory Board
adesso AG

2. HISTORY & ORIGIN
Eberhard Wolff - @ewolff

3. History & Origin
§ Originally started as Ruby PaaS
§ Now: Support for Node.js, Clojure,
Grails, Scala and Python
§ Acquired by Salesforce.com
Eberhard Wolff - @ewolff

4. Programming Model
§ Jetty, Tomcat or Play! web server
§ Worker for background activities
§ Standard Java Programming Model
Eberhard Wolff - @ewolff

5. Scaling / High Availability
§ Servers must be manually started for
scaling
§ Failed servers will be restarted
Eberhard Wolff - @ewolff

6. TOOLS
Eberhard Wolff - @ewolff

7. Command Line Tool
§ heroku
§ E.g. creates new applications
§ Other management functions
addons
o logs
o etc.
o
Eberhard Wolff - @ewolff

8. Deployment
§ heroku tool creates an empty git repository
§ Deploy new versions with git
§ Build (maven) done by Heroku
§ Build automatically deployed
§ No specialized tools needed – git is enough
§ Integration with Atlassian Bamboo or Travis
possible
§ Alternative: WAR deployment
Eberhard Wolff - @ewolff

9. DEMO
Eberhard Wolff - @ewolff

10. Code Changes
Took the Spring application
Converted to PostgreSQL
<bean class="java.net.URI" id="dbUrl">
<constructor-arg
value="#{systemEnvironment['DATABASE_URL']}" />
</bean>
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="url"
value="#{ 'jdbc:postgresql://' + @dbUrl.getHost() + í
':' + @dbUrl.getPort() + @dbUrl.getPath() }" />
<property name="username"
value="#{ @dbUrl.getUserInfo().split(':')[0] }" />
<property name="password"
value="#{ @dbUrl.getUserInfo().split(':')[1] }" />
</bean>
Eberhard Wolff - @ewolff

11. Eberhard Wolff - @ewolff

12. Eberhard Wolff - @ewolff

13. Eberhard Wolff - @ewolff

14. Alternative: Eclipse PlugIn or Web
Eberhard Wolff - @ewolff

15. Full Stack Java EE
No Java EE build pack available
Would need WAR with Java EE libs
Problem: JNDI DataSource
Eberhard Wolff - @ewolff

16. FLEXIBILITY
Eberhard Wolff - @ewolff

17. Flexibility
§ Dynos: processes run on Heroku
§ Procfile defines command line to start a
“Dyno”
§ Can be tuned and changed
§ Can create custom “Buildpack” to run
entirely different environments
§ Available as Open Source e.g. for Ruby,
PHP, Erlang, EmacsLisp…
Eberhard Wolff - @ewolff

18. Restrictions
§ Max source and build artifact size:
200MB
§ No sticky sessions
§ Dynos may not use more than
512MB RAM
§ I.e. max JVM heap about 400MB
Eberhard Wolff - @ewolff

19. PLATFORM AND OTHER
SERVICES
Eberhard Wolff - @ewolff

20. Platform
§ Amazon Web Services
§ US East region
§ EU West beta
§ Proven foundation
§ Can use AWS resources as part of the
solution
§ 750h per month free
Eberhard Wolff - @ewolff

21. Other Services
§ Heroku supports Add-ons
§ Postgresql and memcached by
Heroku
§ Many 3rd party
§ E.g. relational databases, NoSQL
databases, logging, caches…
§ Configuration passed to service via
environment variables
Eberhard Wolff - @ewolff

22. Heroku: Highlights
§ Very flexible: Supports many
different environments
§ Broad range of additional services
§ Also covers build
§ https://github.com/ewolff/newsapplication-heroku
Eberhard Wolff - @ewolff