Clustering : Concurrent operation exception from org.opendaylight.controller.sal-broker while adding PCCs

I generated this error creating 40k LSPs between a single PCC and the artifact from
https://jenkins.opendaylight.org/integration/view/Integration%20jobs/job/integration-master-project-centralized-integration/2771/

deployed as a 3 node cluster on 10.25.2.9 , 10.25.2.10 , 10.25.2.11

1. system:property shard.persistent ${PERSISTENCE}
   PERSISTENT="false"

1. module-shards.conf,
   REPLICA="single"

This bug is similar to https://bugs.opendaylight.org/show_bug.cgi?id=2328 in that it is a race condition involving node creation but I’ll raise another bug as it has different stacktrace and was triggered in a different scenario.

org.opendaylight.controller.sal-broker-impl - 1.2.0.SNAPSHOT | Tx: DOM-19 Error during phase CAN_COMMIT, starting Abort
java.util.concurrent.ExecutionException: OptimisticLockFailedException

{message=Optimistic lock failed., errorList=[RpcError [message=Optimistic lock failed., severity=ERROR, errorType=APPLICATION, tag=resource-denied, applicationTag=null, info=null, cause=org.opendaylight.yangtools.yang.data.api.schema.tree.ConflictingModificationAppliedException: Node was created by other transaction.]]}

at java.util.concurrent.FutureTask.report(Unknown Source)[:1.7.0_60]
at java.util.concurrent.FutureTask.get(Unknown Source)[:1.7.0_60]
at