[2.0.4_java] PersistenceException: java.sql.SQLException: Timed out waiting for a free available connection.

[Diogo Ribeiro]

Hi guys,

I'm building an app in java with Play Framework 2.0.4. The app is deployed in heroku with cleardb database.

Users keep getting this occasional error:
PlayException: Execution exception [[PersistenceException: java.sql.SQLException: Timed out waiting for a free available connection.]]
    at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:134)
    at play.core.ActionInvoker$$anonfun$receive$1.apply(Invoker.scala:115)
    at akka.actor.Actor$class.apply(Actor.scala:318)
    at play.core.ActionInvoker.apply(Invoker.scala:113)
    at akka.actor.ActorCell.invoke(ActorCell.scala:626)
    at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:197)
    at akka.dispatch.Mailbox.run(Mailbox.scala:179)
    at akka.dispatch.ForkJoinExecutorConfigurator$MailboxExecutionTask.exec(AbstractDispatcher.scala:516)
    at akka.jsr166y.ForkJoinTask.doExec(ForkJoinTask.java:259)
    at akka.jsr166y.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:975)
    at akka.jsr166y.ForkJoinPool.runWorker(ForkJoinPool.java:1479)
    at akka.jsr166y.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:104)
Caused by: javax.persistence.PersistenceException: java.sql.SQLException: Timed out waiting for a free available connection.
    at com.avaje.ebeaninternal.server.transaction.TransactionManager.createQueryTransaction(TransactionManager.java:356)
    at com.avaje.ebeaninternal.server.core.DefaultServer.createQueryTransaction(DefaultServer.java:2021)
    at com.avaje.ebeaninternal.server.core.OrmQueryRequest.initTransIfRequired(OrmQueryRequest.java:241)
    at com.avaje.ebeaninternal.server.core.DefaultServer.findId(DefaultServer.java:1212)
    at com.avaje.ebeaninternal.server.core.DefaultServer.find(DefaultServer.java:1118)
    at com.avaje.ebeaninternal.server.core.DefaultServer.find(DefaultServer.java:1105)
    at play.db.ebean.Model$Finder.byId(Model.java:237)

Now is getting worse and sometimes all users get the same error every time until I restart the app in heroku.

Any help or tips to debug it?

Thanks a lot.