Raible Designs

Devoxx France: A Great Conference in a Magnificent City

This week, my lovely fiancé and I traveled to the City of Light. Our journey was designed around some speaking engagements at Devoxx France. Devoxx is one of my favorite conference franchises and Devoxx France has been special to me ever since the Devoxx (Belgium) I spoke at in 2011.

2011 was the year I spoke about my experience with Play, Scala, CoffeeScript and Jade. I wrote the presentation on my flight over, composed the demo video the night before and made it all happen in the nick of time. Of course, this was after 120 hours of research and preparation, so the presentation composition process had all the data I needed. You can imagine my sense of relief after pulling off that talk and getting an enthusiastic applause from the audience for my efforts.

One of the first audience questions I received was from Nicolas Martignole, asking if I'd speak at Devoxx France the following year. I whole-heartedly agreed to do it and was excited for the opportunity. It was with great disappointment that I later found out I couldn't attend Devoxx France in 2012. My client didn't like me taking so much time off and I agreed to scale my two week vacation back to 1 week. This year, I was determined to go, so I submitted some of my favorite talks: Comparing JVM Web Frameworks and The Play vs. Grails Smackdown with James Ward. I was extremely pleased when they both got accepted.

Side Story: I met Martin Odersky shortly when he sat down next to me for the Java Posse presentation in Belgium in 2011. After shaking his hand and introducing myself, I had to politely ask him to leave because it was Trish's seat. Talk about awkward; but Martin was very gracious and promptly found a new seat close by.

Comparing JVM Web Frameworks
Both talks required a bit of updating. For Comparing JVM Web Frameworks, I started reading The Paradox of Choice and found many parallels to the agony that developers experience with choosing a web framework. I described how I didn't think good framework decisions were based on the many, many features that frameworks have, but often on pre-defined constraints. There's those lucky developers that get to choose a Full Stack Framework because they're doing greenfield development. Then there's those that want a better Pure Web Framework that replaces something (e.g. Struts) that's not satisfying their needs. And lastly, there's those that've found it possible to leverage a SOFEA and use a JavaScript MVC framework with an API Framework on the backend. I don't think it makes sense to compare all web frameworks and I tried to use these pre-defined constraints (language, platform and application type) argument to separate into categories and help make choosing easier.

I took out the parts of the presentation that've pissed people off in the past - particular the JSF bashing by James Gosling, the Rails gushing from Craig McClanahan and the Pros and Cons sections of each framework. I added the history of web frameworks and research from InfoQ and devrates.com.

The best part of the JVM Web Frameworks talk was the audience's reaction and enthusiasm. Devoxx always seems to attract passionate developers and Devoxx France was no different. Developers packing the room, clapping after your intro, laughing at your jokes, signifying that they agree with you about JSF. As a speaker, it's an unbelievable experience.

You can view my Comparing JVM Web Frameworks presentation below or on Slideshare.net.

Play Frameworks vs. Grails Smackdown
To prepare for James Ward and my Play vs. Grails Smackdown, we had a number of goals. First of all, we wanted to update our apps to use the latest versions of each framework. I documented what it took for Grails, James just checked in his code to GitHub. It was interesting to see that Grails 2.0.3 -> 2.2.1 caused a number of issues with testing, while Play 2.0.3 -> Play 2.1.0 required API changes, but nothing for tests. Secondly, we updated all the stats for our pretty graphs and ran load tests again.

This is where the fun started. On Tuesday evening, I decided to challenge the notion that Play was twice as fast as Grails. James had proven this with Apache Bench tests. With Play 2.0 and Grails 2.0 (last summer), we clocked Play at 251/requests per second and 198 for Grails. After upgrading each app to the latest releases, we found the numbers to be 233/second for Play and 118 for Grails.

However, Apache Bench only tests until the first byte is received. Since I've done a lot of browser optimizations recently, I fired up whichloadsfaster.com, captured a screenshot and added it to our presentation. The next day, James added a CDN and a bunch of caching to his app and re-ran his AB tests.

Now he was smoking Grails, so I added a CDN and caching as well. However, the best I could do was just over 1000/requests per second, while he was around 2200/second. When he ran live tests during our talk, Play was around 2800/sec and Grails was around 900.

It was great to see how much better performance we could get with caching and a CDN. The best part is this should be available to most applications, not just these frameworks. By adding a CDN (we used Amazon CloudFront) and caching, we were both able to 10x the performance of our apps. You can find our presentation here or view it below.

Summary
This was a very enjoyable conference to attend as a speaker. First of all, it was in one of the most beautiful cities in the world, but it's also a very special place for Trish and I. We got engaged just outside of Paris in Versailles after the last Devoxx conference I spoke at. Trish has some amazing photos from that trip. Secondly, the Devoxx conference attracts a special kind of developer - one that is passionate about and eager for knowledge. Lastly, speaking with my good friend James, in an exotic city about something we love - that was special. Asking for beers and having them brought to us at the start of our Smackdown. That was magical (thanks Nicolas!).

To all the Devoxx organizers and crew - well done on a great show!

Upgrading Grails from 2.0 to 2.2

In preparation for my Grails vs. Play Smackdown at Devoxx France next week, I recently upgraded my Grails version of Happy Trails from Grails 2.0.3 to Grails 2.2.1. I ran into a few issues along the way and figured I'd document them here to help others out.

Fixing the source
The first issue I ran into was Spock and Groovy 2 incompatibilities.

| Resolving plugin JAR dependencies
| Error WARNING: Dependencies cannot be resolved for plugin [mail] due to error: startup failed:
Could not instantiate global transform class org.spockframework.compiler.SpockTransform specified at jar:file:/Users/mraible/.grails/ivy-cache/org.spockframework/spock-core/jars/spock-core-0.7-groovy-1.8.jar!/META-INF/services/org.codehaus.groovy.transform.ASTTransformation  because of exception org.spockframework.util.IncompatibleGroovyVersionException: The Spock compiler plugin cannot execute because Spock 0.7.0-groovy-1.8 is not compatible with Groovy 2.0.7. For more information, see http://versioninfo.spockframework.org

I posted the problem to StackOverflow and got a response almost immediately. While this pull request helped me quite a bit, it was ultimately caused by my vision: I had two "geb-spock" dependencies listed in BuildConfig.groovy with different groupIds.

At this point, I also moved all my plugin dependencies from application.properties to BuildConfig.groovy.

The next problem I ran into was a unit test and functional tests failing. The unit testing issue was caused by my Direction model not being in the tests @Mock annotation. After I added it, validation kicked and I recognized my test was invalid. I added @Ignore and continued.

The functional test seemed to be seemed to be caused by Geb and it trying to use the Chrome Driver. One of my tests didn't work with the default HtmlUnitDriver, so I used the ChromeDriver for the one test.

| Running 11 spock tests... 6 of 11
| Failure:  signup as a new user(happytrails.AuthenticatedUserSpec)
|  org.openqa.selenium.WebDriverException: Unable to either launch or connect to Chrome. Please check that ChromeDriver is up-to-date. Using Chrome binary at: /Applications/Google Chrome.app/Contents/MacOS/Google Chrome (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 45.66 seconds
Build info: version: '2.27.0', revision: '18259', time: '2012-12-05 11:30:53'
System info: os.name: 'Mac OS X', os.arch: 'x86_64', os.version: '10.8.2', java.version: '1.7.0_04'
Driver info: org.openqa.selenium.chrome.ChromeDriver
    at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:187)
    at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:145)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:533)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:216)
    at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:111)
    at org.openqa.selenium.remote.RemoteWebDriver.(RemoteWebDriver.java:115)
    at org.openqa.selenium.chrome.ChromeDriver.(ChromeDriver.java:161)
    at org.openqa.selenium.chrome.ChromeDriver.(ChromeDriver.java:107)
    at happytrails.AuthenticatedUserSpec.signup as a new user(AuthenticatedUserSpec.groovy:25)

Even when running "grails -Dgeb.env=chrome test-app", this still happened. This was caused by the fact that I had GebConfig.groovy in test/functional/happytrails. Move it to test/functional solved the problem. I also discovered that I know longer needed Chrome to get this test to pass. Apparently, the HtmlUnitDriver has issues with Grails 2.2, but it seems to work for me.

After getting the Geb configuration fixed, I ran into a functional test failure:

| Running 11 spock tests... 5 of 11
| Failure:  click signup link(happytrails.AuthenticatedUserSpec)
|  org.openqa.selenium.ElementNotVisibleException: Element must be displayed to click (WARNING: The server did not provide any stacktrace information)

Even though I could see the "signup" link when I ran "grails run-app", I could see that it didn't show up when running tests in Chrome. This turned out to be caused by an extraneous <div class="nav-collapse"> I had in my main.gsp. Removing it solved the problem. It's strange that this never showed up with Grails 2.0. My only guess is that Geb someone didn't look at the visibility of the element.

The last testing-related issue I ran into was a InvalidElementStateException:

| Running 11 spock tests... 7 of 11
| Failure:  add new route to region(happytrails.AuthenticatedUserSpec)
|  org.openqa.selenium.InvalidElementStateException: Element must be user-editable in order to clear it. (WARNING: The server did not provide any stacktrace information)

I was able to fix this by changing AddRoutePage.groovy from:

static content = {
    createButton(to: ShowRoutePage) { create() }
    name { value("Name") }
    distance { value("Distance") }
    location { value("Location") }
}

To:

static content = {
    createButton(to: ShowRoutePage) { create() }
    form { $("form") }
}

And then referencing name, distance and location accordingly (form.name, etc.) in AuthenticatedUserSpec.groovy.

CloudBees
After I had everything working locally, I logged into Jenkins on CloudBees. Since I hadn't used it in a while, I had to wait a bit while my Jenkins server was re-commissioned. Once it was up, I tried to select Grails 2.2.1 to build with, but found it wasn't available. After a tweeting this, I learned about Grails Wrapper, found that the latest Grails Jenkins plugin supported it and got everything working. I later discovered that CloudBees does support Grails 2.2.1, I just needed to setup another Grails installation to automatically download and install 2.2.1.

Heroku
The last two issues I ran into were with Heroku. Since I was upgrading everything, I wanted Grails to build/run under Java 7 and use Servlet 3. I changed the appropriate properties in BuildConfig.groovy, configured Heroku and deployed. No dice.

Error Compilation error: startup failed:
Invalid commandline usage for javac.
javac: invalid source release: 1.7
Usage: javac  
use -help for a list of possible options

Sidenote: I tried building with Java 8 on CloudBees, but discovered the searchable plugin doesn't support it.

Compile error during compilation with javac.
/scratch/jenkins/workspace/Happy Trails - Grails 2/work/plugins/searchable-0.6.4/src/java/grails/plugin/searchable/internal/compass/index/DefaultUnindexMethod.java:94: error: reference to delete is ambiguous
                    session.delete(query);
                           ^
  both method delete(CompassQuery) in CompassOperations and method delete(CompassQuery) in CompassIndexSession match

As far as Servlet 3, it was pretty obvious that the Jetty version Heroku uses for Grails doesn't support it. Therefore, I reverted back to Servlet 2.5.

java.lang.NoClassDefFoundError: javax/servlet/AsyncContext
	at org.codehaus.groovy.util.LazyReference.getLocked(LazyReference.java:46)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:59)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2444)

I sent the Java 7 issue to Heroku Support a few days ago but haven't heard back yet.

Summary
While upgrading Grails from 2.0 to 2.2 wasn't as easy as expected, it is understandable. After all, Grails 2.2 ships with Groovy 2.0, which has a bunch of new features itself. All the issues I ran into were fairly easy to solve, except for Java 7 on Heroku. But hey, what do you expect from a free hosting service?

If you're at Devoxx France next week, I look forward to sharing our research on Grails 2.2.1 vs. Play 2.1.0.

How do you choose web framework candidates to compare?

David Díaz Clavijo sent me an email a couple weeks ago asking me about comparing web frameworks. David is a computer engineering student at the University of Las Palmas de Gran Canaria (ULPGC) in the Canary Islands, Spain. His FYP (Final Year Project) is a web frameworks comparison focused on high productivity frameworks. He's started a blog to help facilitate his work and has been writing some interesting posts.

Today, he wrote about the web frameworks he's decided to compare and inspired me to respond to his original request for my thoughts.

Hello David,

Sorry it took me so long to respond. I think your approach as far as learning the language, making exercises, learning the framework and developing the website is good. As you know, the last one you develop with will likely do well because you're repeated the steps so much with the other ones.

However, there's one thing I think you're doing wrong. In the real world, I don't believe that an architect would look at *all* the available web frameworks and choose one. I believe most of them already have a language bias or there's a target platform (e.g. LAMP, JVM, etc.).

I believe the majority of development happens today where a platform is already in place. Even moreso, the backend may already be in place and the company is simply trying to find a more productive front-end framework. In the first instance, where the platform is already chosen, the chooser's options are immediately limited. For example, if it's the JVM, Django might be eliminated because JPython isn't that up-to-snuff or widely used (this could be changing). However, it could be said that all the frameworks you've chosen (including Code Igniter) can run on the JVM.

I just don't see people identifying web frameworks across such a wide variety of languages. I think folks generally choose a platform, then a language, then a framework. It's possible that startups will do it differently by choosing a language first. However, I imagine most startups have a technical founder that already has some preference towards a particular language.

Now it's your turn, dear readers. Have you ever been in a situation where you've been able to pick a web framework across all languages? Did any of your biases enter into the equation?

How would you recommend David go about choosing web framework candidates?

Integrating GWT into AppFuse

I've been interested in integrating GWT into AppFuse ever since I blogged about it 4 years ago. A few months after that post, I wrote about Enhancing Evite.com with GWT and Grails. After Evite, I had a gig near Boston where I developed with GXT for the remainder of the year. When all was said and done, I ended up spending a year with GWT and really enjoyed my experience. I haven't used it much since.

GWT is scheduled to be integrated into AppFuse in version 4.0. That's quite a ways off. The good news is you might not have to wait that long, thanks to Iván García Sainz-Aja. Iván let us know about his work a couple weeks ago in an email to the appfuse-dev mailing list.

web/gwt> mvn -P gwtDebug -Dgwt.inplace=true gwt:compile jetty:run  

As you can imagine, I was very excited to hear about Iván's work. So I cloned his repo, built gwt-bootstrap locally and checked it out. Functionality wise, it was great! However, when I dug into the source code, I found a whole lotta code.

To see how the GWT flavor compared to the other implementations in AppFuse, I created a cloc report on the various web frameworks in AppFuse. I'm sure these reports could be adjusted to be more accurate, but I believe they give a good general overview. I posted some graphs that displays my findings in visual form.

When I sent this to the mailing list, Ivan responded that it was a lot of code and estimated 12 new files would be needed to CRUD an entity. This sure seems like a lot to me, but he defended this yesterday and noted that his implementation follows many of GWT's latest best practices: MVP pattern, Activities and Places, EventBus, Gin and Guice. He also shared a wiki page with explanations and diagrams of how things work.

The reason I'm writing this post is to get more feedback on this implementation. First of all, does GWT really require this much code? Secondly, are there other GWT implementations that reduce a lot of the boilerplate? SmartGWT, Vaadin* and Errai come to mind.

If you were starting a new GWT project and using AppFuse, how would you want it implemented?

* Vaadin 7 claims it can be used as a drop-in replacement for GWT. I tried replacing the gwt-servlet and gwt-user dependencies with Vaadin's, but it didn't work.