We have observed this behavior in CSIT:

2017-04-25 17:26:09,638 | INFO | lt-dispatcher-16 | ShardManager | 199 - org.opendaylight.controller.sal-distributed-datastore - 1.5.0.SNAPSHOT | shard-manager-config: Received LeaderStateChanged message: LeaderStateChanged [memberId=member-1-shard-default-config, leaderId=null, leaderPayloadVersion=-1]
2017-04-25 17:26:09,638 | INFO | lt-dispatcher-21 | RoleChangeNotifier | 192 - org.opendaylight.controller.sal-clustering-commons - 1.5.0.SNAPSHOT | RoleChangeNotifier for member-1-shard-default-config , received role change from Leader to Follower
2017-04-25 17:26:09,638 | INFO | ult-dispatcher-3 | ShardManager | 199 - org.opendaylight.controller.sal-distributed-datastore - 1.5.0.SNAPSHOT | shard-manager-config: Received role changed for member-1-shard-default-config from Leader to Follower
2017-04-25 17:26:09,654 | INFO | lt-dispatcher-20 | ClientActorBehavior | 197 - org.opendaylight.controller.cds-access-client - 1.1.0.SNAPSHOT | member-1-frontend-datastore-config: connection org.opendaylight.controller.cluster.access.client.ConnectedClientConnection@54b02f0c indicated no leadership, reconnecting it
org.opendaylight.controller.cluster.access.commands.NotLeaderException: Actor Actorakka://opendaylight-cluster-data/user/shardmanager-config/member-1-shard-default-config#-1832590307 is not the current leader
at org.opendaylight.controller.cluster.datastore.Shard.handleRequest(Shard.java:443)[199:org.opendaylight.controller.sal-distributed-datastore:1.5.0.SNAPSHOT]
at org.opendaylight.controller.cluster.datastore.Shard.handleNonRaftCommand(Shard.java:283)[199:org.opendaylight.controller.sal-distributed-datastore:1.5.0.SNAPSHOT]
at org.opendaylight.controller.cluster.raft.RaftActor.handleCommand(RaftActor.java:270)[193:org.opendaylight.controller.sal-akka-raft:1.5.0.SNAPSHOT]
at org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActor.onReceiveCommand(AbstractUntypedPersistentActor.java:31)[192:org.opendaylight.controller.sal-clustering-commons:1.5.0.SNAPSHOT]
at akka.persistence.UntypedPersistentActor.onReceive(PersistentActor.scala:170)[180:com.typesafe.akka.persistence:2.4.17]
at org.opendaylight.controller.cluster.common.actor.MeteringBehavior.apply(MeteringBehavior.java:104)[192:org.opendaylight.controller.sal-clustering-commons:1.5.0.SNAPSHOT]
at akka.actor.ActorCell$$anonfun$become$1.applyOrElse(ActorCell.scala:544)[173:com.typesafe.akka.actor:2.4.17]
at akka.actor.Actor$class.aroundReceive(Actor.scala:497)[173:com.typesafe.akka.actor:2.4.17]
at akka.persistence.UntypedPersistentActor.akka$persistence$Eventsourced$$super$aroundReceive(PersistentActor.scala:168)[180:com.typesafe.akka.persistence:2.4.17]
at akka.persistence.Eventsourced$$anon$1.stateReceive(Eventsourced.scala:664)[180:com.typesafe.akka.persistence:2.4.17]
at akka.persistence.Eventsourced$class.aroundReceive(Eventsourced.scala:183)[180:com.typesafe.akka.persistence:2.4.17]
at akka.persistence.UntypedPersistentActor.aroundReceive(PersistentActor.scala:168)[180:com.typesafe.akka.persistence:2.4.17]
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)[173:com.typesafe.akka.actor:2.4.17]
at akka.actor.ActorCell.invoke(ActorCell.scala:495)[173:com.typesafe.akka.actor:2.4.17]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)[173:com.typesafe.akka.actor:2.4.17]
at akka.dispatch.Mailbox.run(Mailbox.scala:224)[173:com.typesafe.akka.actor:2.4.17]
at akka.dispatch.Mailbox.exec(Mailbox.scala:234)[173:com.typesafe.akka.actor:2.4.17]
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
2017-04-25 17:26:09,673 | ERROR | lt-dispatcher-20 | EndpointWriter | 174 - com.typesafe.akka.slf4j - 2.4.17 | Failed to serialize remote message [class org.opendaylight.controller.cluster.access.concepts.RequestEnvelope] using serializer [class akka.serialization.JavaSerializer]. Transient association error (association remains live)
akka.remote.MessageSerializer$SerializationException: Failed to serialize remote message [class org.opendaylight.controller.cluster.access.concepts.RequestEnvelope] using serializer [class akka.serialization.JavaSerializer].
at akka.remote.MessageSerializer$.serialize(MessageSerializer.scala:61)[183:com.typesafe.akka.remote:2.4.17]
at akka.remote.EndpointWriter$$anonfun$serializeMessage$1.apply(Endpoint.scala:895)[183:com.typesafe.akka.remote:2.4.17]
at akka.remote.EndpointWriter$$anonfun$serializeMessage$1.apply(Endpoint.scala:895)[183:com.typesafe.akka.remote:2.4.17]
at scala.util.DynamicVariable.withValue(DynamicVariable.scala:58)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at akka.remote.EndpointWriter.serializeMessage(Endpoint.scala:894)[183:com.typesafe.akka.remote:2.4.17]
at akka.remote.EndpointWriter.writeSend(Endpoint.scala:786)[183:com.typesafe.akka.remote:2.4.17]
at akka.remote.EndpointWriter$$anonfun$4.applyOrElse(Endpoint.scala:761)[183:com.typesafe.akka.remote:2.4.17]
at akka.actor.Actor$class.aroundReceive(Actor.scala:497)[173:com.typesafe.akka.actor:2.4.17]
at akka.remote.EndpointActor.aroundReceive(Endpoint.scala:452)[183:com.typesafe.akka.remote:2.4.17]
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)[173:com.typesafe.akka.actor:2.4.17]
at akka.actor.ActorCell.invoke(ActorCell.scala:495)[173:com.typesafe.akka.actor:2.4.17]
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)[173:com.typesafe.akka.actor:2.4.17]
at akka.dispatch.Mailbox.run(Mailbox.scala:224)[173:com.typesafe.akka.actor:2.4.17]
at akka.dispatch.Mailbox.exec(Mailbox.scala:234)[173:com.typesafe.akka.actor:2.4.17]
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
Caused by: java.lang.UnsupportedOperationException: Local transaction request should never be serialized
at org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest.externalizableProxy(AbstractLocalTransactionRequest.java:34)[196:org.opendaylight.controller.cds-access-api:1.1.0.SNAPSHOT]
at org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest.externalizableProxy(AbstractLocalTransactionRequest.java:23)[196:org.opendaylight.controller.cds-access-api:1.1.0.SNAPSHOT]
at org.opendaylight.controller.cluster.access.concepts.Request.externalizableProxy(Request.java:27)[196:org.opendaylight.controller.cds-access-api:1.1.0.SNAPSHOT]
at org.opendaylight.controller.cluster.access.concepts.Message.writeReplace(Message.java:170)[196:org.opendaylight.controller.cds-access-api:1.1.0.SNAPSHOT]
at sun.reflect.GeneratedMethodAccessor79.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)[:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498)[:1.8.0_121]
at java.io.ObjectStreamClass.invokeWriteReplace(ObjectStreamClass.java:1118)[:1.8.0_121]
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1136)[:1.8.0_121]
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)[:1.8.0_121]
at org.opendaylight.controller.cluster.access.concepts.AbstractEnvelopeProxy.writeExternal(AbstractEnvelopeProxy.java:36)[196:org.opendaylight.controller.cds-access-api:1.1.0.SNAPSHOT]
at java.io.ObjectOutputStream.writeExternalData(ObjectOutputStream.java:1459)[:1.8.0_121]
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1430)[:1.8.0_121]
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)[:1.8.0_121]
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)[:1.8.0_121]
at akka.serialization.JavaSerializer$$anonfun$toBinary$1.apply$mcV$sp(Serializer.scala:321)[173:com.typesafe.akka.actor:2.4.17]
at akka.serialization.JavaSerializer$$anonfun$toBinary$1.apply(Serializer.scala:321)[173:com.typesafe.akka.actor:2.4.17]
at akka.serialization.JavaSerializer$$anonfun$toBinary$1.apply(Serializer.scala:321)[173:com.typesafe.akka.actor:2.4.17]
at scala.util.DynamicVariable.withValue(DynamicVariable.scala:58)[169:org.scala-lang.scala-library:2.11.8.v20160304-115712-1706a37eb8]
at akka.serialization.JavaSerializer.toBinary(Serializer.scala:321)[173:com.typesafe.akka.actor:2.4.17]
at akka.remote.MessageSerializer$.serialize(MessageSerializer.scala:47)[183:com.typesafe.akka.remote:2.4.17]
... 17 more