I've been using the Play framework since I started at RtR 3 months ago. Last week, I made the decision that no new services will be written in Play from that point forward. It started out as a great little framework that was pretty quick to learn and easy to use, but it's turned into something that I would not recommend anyone use for serious production applications. What happened?
First, I lost faith in the developers.
One of the first things that annoyed me about Play was the inability to run a single test from within a play test class inside your IDE. I suppose the thinking was that you will always run the play test app, or something, but I prefer to leave my IDE as little as possible when I'm working, and running an entire test class worked fine. So, being the good little open source programmer that I am, instead of bitching I rolled up my sleeves and fixed the bug. It was a pretty trivial fix. I even wrote a test case. Then I put in a pull request and waited.
After submitting the pull request, I commented on the pull request, commented on the ticket, and finally sent an email to the mailing list. And the response I got was basically that the team is too busy working on the next generation of the product to absorb fixes for the older generation. Having worked on open source projects myself, I understand what it's like to have limited bandwidth to look at changes. But if the project team's bandwidth is so limited that they can't even afford to look at small fixes like this, it seems like the project is basically abandoned. At that point I lost faith that I could rely on the community to support the 1.X branch of this product. Not necessarily a dealbreaker, but definitely a bad sign.
Then, I lost faith in the platform.
We started to hit some serious bugs in the platform during a big push on a complex service. First, our developers that used Mac and Windows hit a bug similar to this, where they just simply couldn't get the app to work no matter what they did. It worked fine in linux, but even a clean checkout would fail to run for them. It was inexplicable, irritating, and we lost a couple of days of development work trying to get around it (rolling back checkins, pulling out modules, poring through stack traces). By this point, I had lost faith in the community, so I didn't see the point in going to them for help. Fortunately, we did finally get around it (it seemed to be a bug in the CRUD module), but we were all really frustrated and annoyed with the framwork after that experience.
Finally, I lost faith in my own ability to debug the framework.
The issues above were enough for me to want to move off of Play for new projects. The thing that caused me to move off of Play for projects that are already in development (but not in production) was this: At some point, we had written a migration job in Play for a major data migration. We discovered the strangest thing would happen. The job would run across several job threads, and at some point, one of the threads would hang. But it would not hang in a way that I have ever seen a JVM thread hang. The thread was in RUNNABLE state, and it was in a HashMap method (either get or put) and it was just sitting there. Not doing anything. No locks, no database or other IO, plenty of memory, plenty of resources, just sitting in that HashMap.get method, hanging out.
Now, maybe you've seen that before (and if you have, please leave a comment!). But I have seen a lot of JVM issues in my day, and this is a new one. There was no reason for this thread to be hung. And yet it was. I can debug just about anything you can throw at me in Java, but I had absolutely nowhere to start looking to debug this issue, except a vague suspicion that it was related to the way the framework was rewriting the classes under the covers. That is a dealbreaker, ladies and gents. I could've probably debugged why the module was causing the app to crap out for my developers, if given enough time. But I cannot say with any certainty that I could debug whatever the hell was causing that thread to hang.
If I felt the developers supporting play were committed to building a real community of support around the 1.X version, I might have stayed with it longer. It's a giant pain to find something else that is easy, lightweight, supports JPA and doesn't force me to write XML. But I can't use a product that I know has issues even I can't debug, and a team I don't trust to maintain the product to the standards my team needs to confidently use it in production.