OpenFlowPlugin or some openflow application tries to read data from a closed transaction

To reproduce this problem start the controller and install the odl-mdsal-clustering feature. Then connect mininet to it. You should start seeing exceptions like this,

2015-02-13 14:41:24,467 | ERROR | lt-dispatcher-34 | ShardReadWriteTransaction | 170 - org.opendaylight.controller.sal-clustering-commons - 1.2.0.SNAPSHOT | Unexpected error reading path /(urn:opendaylight:inventory?revision=2013-08-19)nodes/node/node[

{(urn:opendaylight:inventory?revision=2013-08-19)id=openflow:108}

]/AugmentationIdentifier

{childNames=[(urn:opendaylight:flow:inventory?revision=2013-08-19)table, (urn:opendaylight:flow:inventory?revision=2013-08-19)meter, (urn:opendaylight:flow:inventory?revision=2013-08-19)supported-instructions, (urn:opendaylight:flow:inventory?revision=2013-08-19)switch-features, (urn:opendaylight:flow:inventory?revision=2013-08-19)group, (urn:opendaylight:flow:inventory?revision=2013-08-19)manufacturer, (urn:opendaylight:flow:inventory?revision=2013-08-19)hardware, (urn:opendaylight:flow:inventory?revision=2013-08-19)ip-address, (urn:opendaylight:flow:inventory?revision=2013-08-19)software, (urn:opendaylight:flow:inventory?revision=2013-08-19)supported-actions, (urn:opendaylight:flow:inventory?revision=2013-08-19)supported-match-types, (urn:opendaylight:flow:inventory?revision=2013-08-19)description, (urn:opendaylight:flow:inventory?revision=2013-08-19)serial-number]}

ReadFailedException

{message=Transaction is closed, errorList=[RpcError [message=Transaction is closed, severity=ERROR, errorType=APPLICATION, tag=operation-failed, applicationTag=null, info=null, cause=null]]}

at org.opendaylight.controller.md.sal.dom.store.impl.SnapshotBackedReadWriteTransaction.read(SnapshotBackedReadWriteTransaction.java:56)[159:org.opendaylight.controller.sal-inmemory-datastore:1.2.0.SNAPSHOT]
at org.opendaylight.controller.cluster.datastore.ShardTransaction.readData(ShardTransaction.java:130)[178:org.opendaylight.controller.sal-distributed-datastore:1.2.0.SNAPSHOT]
at org.opendaylight.controller.cluster.datastore.ShardReadWriteTransaction.handleReceive(ShardReadWriteTransaction.java:37)[178:org.opendaylight.controller.sal-distributed-datastore:1.2.0.SNAPSHOT]
at org.opendaylight.controller.cluster.common.actor.AbstractUntypedActor.onReceive(AbstractUntypedActor.java:34)[170:org.opendaylight.controller.sal-clustering-commons:1.2.0.SNAPSHOT]
at org.opendaylight.controller.cluster.common.actor.MeteringBehavior.apply(MeteringBehavior.java:96)[170:org.opendaylight.controller.sal-clustering-commons:1.2.0.SNAPSHOT]
at akka.actor.ActorCell$$anonfun$become$1.applyOrElse(ActorCell.scala:534)[163:com.typesafe.akka.actor:2.3.4]
at akka.actor.Actor$class.aroundReceive(Actor.scala:465)[163:com.typesafe.akka.actor:2.3.4]
at akka.actor.UntypedActor.aroundReceive(UntypedActor.scala:97)[163:com.typesafe.akka.actor:2.3.4]
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516)[163:com.typesafe.akka.actor:2.3.4]
at akka.actor.ActorCell.invoke(ActorCell.scala:487)[163:com.typesafe.akka.actor:2.3.4]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238)[163:com.typesafe.akka.actor:2.3.4]
at akka.dispatch.Mailbox.run(Mailbox.scala:220)[163:com.typesafe.akka.actor:2.3.4]
at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:393)[163:com.typesafe.akka.actor:2.3.4]
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)[160:org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)[160:org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)[160:org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)[160:org.scala-lang.scala-library:2.10.4.v20140209-180020-VFINAL-b66a39653b]