Intro to Play 2

My Top 10 Favorite Features

• 0) Simple
• 1) URL Routing
• 2) Class Reloading
• 3) Share-Nothing
• 4) Java & Scala Support
• 5) Great Testing Support
• 6) JPA/EBean Support
• 7) NIO Server (Netty)
• 8) Asset Compiler
• 9) Instant Deployment on Heroku

Intro to Grails 2

My Top 10 Favorite Features

1. Documentation
2. Clean URLs
3. GORM
4. IntelliJ IDEA Support
5. Zero Turnaround
6. Excellent Testing Support
7. Groovy
8. GSPs
9. Resource Optimizer
10. Instant Deployment on Heroku

Code Walk Through

We developed the same app, in similar ways, so let's look at the different layers.

Database - Grails

• Hibernate is the default persistence provider
• Create models, Hibernate creates the schema for you

grails-app/conf/DataSource.groovy

Database - Play

• EBean is the default persistence provider in Java projects
• Evolutions can be auto-applied
• Initial evolution sql is auto-created
• Subsequent changes must be versioned
• Auto-created schema file is database dependent
• Play 2 supports multiple datasources (Play 1 does not)

conf/evolutions/default/2.sql

Database - Play

Using Heroku Postgres in production rocks!

• Postgres 9.1
• Dataclips
• Fork & Follow
• Multi-Ingres

URL Mapping - Grails

grails-app/conf/UrlMappings.groovy

URL Mapping - Play

conf/routes

Models - Grails

• All properties are persisted by default
• Constraints
• Mappings with hasMany and belongsTo
• Override methods for lifecycle events

grails-app/domain/happytrails/Region.groovy

Models - Play

• EBean + JPA Annotations
• Declarative Validations (JSR 303)
• Query DSL
• Lazy Loading (except in Scala Templates)

app/models/Direction.java

Controllers - Grails

grails-app/controllers/happytrails/HomeController.groovy

Controllers - Play

• Stateless - Composable - Interceptable
• Clean connection between URLs and response code

app/controllers/RouteController.java

Views - Grails

• Groovy Server Pages, like JSPs
• GSP Tags
• Layouts and Templates
• Optimized Resources

grails-app/views/region/show.gsp

Views - Play

• Scala Templates
• Composable
• Compiled

app/views/region.scala.html

Validation - Grails

grails-app/controllers/happytrails/RouteController.groovy

grails-app/views/route/create.gsp

Validation - Play

app/controllers/RouteController.java

app/views/signupForm.scala.html

IDE Support - Grails

IntelliJ Rocks!

IDE Support - Play

• $ play idea
• $ play eclipsify
  
  
• Java!!!
• Debugging Support via Remote Debugger
• Limited Testing within IDE

Job - Grails

grails-app/jobs/happytrails/DailyRegionDigestEmailJob.groovy

Job - Play

• Plain old `static void main`
• Independent of web app

app/jobs/DailyRegionDigestEmailJob.java

Feed - Grails

1. grails install-plugin feeds
2. Add feed() method to controller

grails-app/controllers/happytrails/RegionController.groovy

Feed - Play

• No direct RSS/Atom support
• Dependency: "rome" % "rome" % "1.0"

app/jobs/DailyRegionDigestEmailJob.java

Email - Grails

grails-app/jobs/happytrails/DailyRegionDigestEmailJob.groovy

* powered by the mail plugin (built-in)

Email - Play

• SendGrid Heroku Add-on
• Dependency:
  "com.typesafe" %% "play-plugins-mailer" % "2.0.2"

app/jobs/DailyRegionDigestEmailJob.java

conf/prod.conf

Photo Upload - Grails

Photo Upload - Play

• Amazon S3 for Persistent File Storage

app/models/S3Photo.java

app/controllers/RegionController.java

Testing - Grails

• Unit Tests with @TestFor and @Mock
• Test URL Mappings with UrlMappingsUnitTestMixin
• Integration Testing with GroovyTestCase
• Functional Testing with Geb

test/unit/happytrails/RouteTests.groovy

* Grails plugins often aren't in test scope.

Testing - Play

• Standard JUnit
• Unit Tests & Functional Tests
• FakeApplication, FakeRequest, inMemoryDatabase
• Test: Controllers, Views, Routing, Real Server, Browser

test/ApplicationControllerTest.java

Demo Data - Grails

grails-app/conf/BootStrap.groovy

Demo Data - Play

app/Global.java

Configuration - Grails

grails-app/conf/Config.groovy

Configuration - Play

• Based on the TypeSafe Config Library
• Override config with Java Properties:
  -Dfoo=bar
• Environment Variable substitution
• Run with different config files:
  -Dconfig.file=conf/prod.conf

conf/prod.conf

Authentication - Grails

Spring Security UI Plugin, I love you!

grails-app/conf/Config.groovy

Authentication - Play

• Uses cookies to remain stateless

app/controllers/Secured.java

app/controllers/RegionController.java

Application Comparison

• YSlow
• PageSpeed
• Lines of Code
• Load Testing

YSlow

PageSpeed

Lines of Code

Load Testing with BrowserMob

Load Testing - 1 Dyno

Bike (Grails)

Hike (Play)

Load Testing - 1 Dyno

Load Testing - 5 Dynos

Bike (Grails)

Hike (Play)

Load Testing - 5 Dynos

Load Testing - 5 Dynos

Load Testing - 5 Dynos + 100 users

Grails 2 vs. Play 2

• Jobs
• LinkedIn Skills
• Google Trends
• Indeed
• Mailing List Traffic
• Books on Amazon
• 2012 Releases
• Stack Overflow
• Hacker News

Jobs

LinkedIn Skills

Google Trends

Indeed Job Trends

User Mailing List Traffic

Books on Amazon

2012 Releases

StackOverflow Questions

Hacker News

Conclusions: Code

• From a code perspective, very similar frameworks.
• Code authoring good in both, but lacking for Scala Templates.
• Grails Plugin Ecosystem is excellent.
• TDD-Style Development easy with both.
• Type-safety in Play 2 was really useful, especially routes.

Conclusions: Statistical Analysis

• Grails has better support for FEO (YSlow, PageSpeed)
• Grails has less LOC! (6 lines less, but 40% more files)
• 1 Dyno - Grails had 2x transactions!
  • Grails experienced OOM about halfway through.
• Apache Benchmark with 10K requests:
  • Requests per second: {Play: 251, Grails: 198}
• Load Test with 100 Real Users:
  • Grails: 10% more transactions, 0 errors

Conclusions: Ecosystem Analysis

• "Play" is difficult to search for.
• Grails is more mature.
• Play has momentum issues.
• LinkedIn: more people know Grails than Spring MVC.
• Play has 3x user mailing list traffic.
• We had similar experiences with documentation and questions.
• Outdated documentation is a problem for both.
• Play has way more hype!