Check out ODL controller from master trunck. The version appears error about "akka.pattern.AskTimeoutException: Ask timed out on" when committing two million transaction count.

2016-12-20 01:00:17,609 | ERROR | tp1480376227-374 | SimpletxBaWrite | 334 - org.opendaylight.controller.dsbenchmark - 1.3.0.SNAPSHOT | Transaction failed: TransactionCommitFailedException

{message=canCommit encountered an unexpected failure, errorList=[RpcError [message=canCommit encountered an unexpected failure, severity=ERROR, errorType=APPLICATION, tag=operation-failed, applicationTag=null, info=null, cause=akka.pattern.AskTimeoutException: Ask timed out on [ActorSelection[Anchor(akka://opendaylight-cluster-data/), Path(/user/shardmanager-config/member-1-shard-default-config#142705280)]] after [30000 ms]. Sender[null] sent message of type "org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction".]]}

......

2016-12-20 01:00:47,621 | ERROR | t-dispatcher-211 | LocalThreePhaseCommitCohort | 214 - org.opendaylight.controller.sal-distributed-datastore - 1.5.0.SNAPSHOT | Failed to prepare transaction member-1-datastore-config-fe-0-txn-1137579 on backend
akka.pattern.AskTimeoutException: Ask timed out on ActorSelection[Anchor(akka://opendaylight-cluster-data/), Path(/user/shardmanager-config/member-1-shard-default-config#142705280)] after [30000 ms]. Sender[null] sent message of type "org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction".