In a Clustered setup with 3 ODL Controllers and 3 Compute nodes, while running rally with a light load of concurrency of 2 and times set to 40, the following exception was seen in karaf.

ODL rpm used:
opendaylight-6.2.0-0.1.20170913snap58.el7.noarch.rpm

2017-09-15 05:38:29,040 | ERROR | CommitFutures-4 | TransactionChainManager | 304 - org.opendaylight.openflowplugin.common - 0.4.2.SNAPSHOT | Transaction commit failed.
TransactionCommitFailedException{message=Data did not pass validation., errorList=[RpcError [message=Data did not pass validation., severity=ERROR, errorType=APPLICATION, tag=operation-failed, applicationTag=null, info=null, cause=org.opendaylight.yangtools.yang.data.api.schema.tree.ModifiedNodeDoesNotExistException: Node /(urn:opendaylight:inventory?revision=2013-08-19)nodes/node/node[

{(urn:opendaylight:inventory?revision=2013-08-19)id=openflow:238577208939665}

]/AugmentationIdentifier

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

/(urn:opendaylight:flow:inventory?revision=2013-08-19)group/group[

{(urn:opendaylight:flow:inventory?revision=2013-08-19)group-id=212003}

] does not exist. Cannot apply modification to its children.]]}
at org.opendaylight.controller.cluster.datastore.ShardDataTree.lambda$processNextPendingTransaction$0(ShardDataTree.java:760)
at org.opendaylight.controller.cluster.datastore.ShardDataTree.processNextPending(ShardDataTree.java:789)
at org.opendaylight.controller.cluster.datastore.ShardDataTree.processNextPendingTransaction(ShardDataTree.java:736)
at org.opendaylight.controller.cluster.datastore.ShardDataTree.startCanCommit(ShardDataTree.java:819)
at org.opendaylight.controller.cluster.datastore.SimpleShardDataTreeCohort.canCommit(SimpleShardDataTreeCohort.java:90)
at org.opendaylight.controller.cluster.datastore.ChainedCommitCohort.canCommit(ChainedCommitCohort.java:58)
at org.opendaylight.controller.cluster.datastore.CohortEntry.canCommit(CohortEntry.java:97)
at org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.handleCanCommit(ShardCommitCoordinator.java:236)
at org.opendaylight.controller.cluster.datastore.ShardCommitCoordinator.handleForwardedReadyTransaction(ShardCommitCoordinator.java:114)
at org.opendaylight.controller.cluster.datastore.Shard.handleForwardedReadyTransaction(Shard.java:699)
at org.opendaylight.controller.cluster.datastore.Shard.handleNonRaftCommand(Shard.java:314)
at org.opendaylight.controller.cluster.raft.RaftActor.handleCommand(RaftActor.java:270)
at org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActor.onReceiveCommand(AbstractUntypedPersistentActor.java:44)
at akka.persistence.UntypedPersistentActor.onReceive(PersistentActor.scala:170)
at org.opendaylight.controller.cluster.common.actor.MeteringBehavior.apply(MeteringBehavior.java:104)
at akka.actor.ActorCell$$anonfun$become$1.applyOrElse(ActorCell.scala:544)
at akka.actor.Actor$class.aroundReceive(Actor.scala:502)
at akka.persistence.UntypedPersistentActor.akka$persistence$Eventsourced$$super$aroundReceive(PersistentActor.scala:168)
at akka.persistence.Eventsourced$$anon$1.stateReceive(Eventsourced.scala:727)
at akka.persistence.Eventsourced$class.aroundReceive(Eventsourced.scala:183)
at akka.persistence.UntypedPersistentActor.aroundReceive(PersistentActor.scala:168)
at akka.actor.ActorCell.receiveMessage(ActorCell.scala:526)
at akka.actor.ActorCell.invoke(ActorCell.scala:495)
at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:257)
at akka.dispatch.Mailbox.run(Mailbox.scala:224)
at akka.dispatch.Mailbox.exec(Mailbox.scala:234)
at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
Caused by: org.opendaylight.yangtools.yang.data.api.schema.tree.ModifiedNodeDoesNotExistException: Node /(urn:opendaylight:inventory?revision=2013-08-19)nodes/node/node[

{(urn:opendaylight:inventory?revision=2013-08-19)id=openflow:238577208939665}

]/AugmentationIdentifier

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

/(urn:opendaylight:flow:inventory?revision=2013-08-19)group/group[

{(urn:opendaylight:flow:inventory?revision=2013-08-19)group-id=212003}

] does not exist. Cannot apply modification to its children.
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:281)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkChildPreconditions(AbstractNodeContainerModificationStrategy.java:305)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:288)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkChildPreconditions(AbstractNodeContainerModificationStrategy.java:305)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:288)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkChildPreconditions(AbstractNodeContainerModificationStrategy.java:305)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:288)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkChildPreconditions(AbstractNodeContainerModificationStrategy.java:305)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:288)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkChildPreconditions(AbstractNodeContainerModificationStrategy.java:305)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:288)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.StructuralContainerModificationStrategy.checkApplicable(StructuralContainerModificationStrategy.java:99)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkChildPreconditions(AbstractNodeContainerModificationStrategy.java:305)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractNodeContainerModificationStrategy.checkTouchApplicable(AbstractNodeContainerModificationStrategy.java:288)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaAwareApplyOperation.checkApplicable(SchemaAwareApplyOperation.java:125)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.RootModificationApplyOperation.checkApplicable(RootModificationApplyOperation.java:72)
at org.opendaylight.yangtools.yang.data.impl.schema.tree.AbstractDataTreeTip.validate(AbstractDataTreeTip.java:35)
at org.opendaylight.controller.cluster.datastore.ShardDataTree.lambda$processNextPendingTransaction$0(ShardDataTree.java:743)
... 29 more