This class defines a BackendTransfer message used to transfer the backend
information and re-enable the backend on the remote controller (checkpoint
transfer have already been taken care of).
This class defines a FlushGroupCommunicationMessages used to flush the
messages in the group communication and make sure that controller failover
can be started.
This class defines a GetRequestResultFromFailoverCache message that fetches
the result of a specific request identified by its unique id in the failover
cache.
This class defines a NotifyCompletion command that is sent to controllers
that have either failed (AllBackendsFailedException) or did not execute the
query (NoMoreBackendException) to notify of the success or failure of the
request execution.
This class defines a inconsistency notification command that is sent to
controllers that reported a result that is inconsistent with other
controllers.
This message is used both to prepare the sending of a set of log entries to a
remote controller's vdb recovery log (intialization) and to terminate it
(termination).