Package org.opendaylight.controller.cluster.raft

Interface RaftActorSnapshotCohort

All Known Implementing Classes:

NoopRaftActorSnapshotCohort

public interface RaftActorSnapshotCohort

Interface for a class that participates in raft actor snapshotting.

Author:

Thomas Pantelis

Method Summary

Modifier and Type	Method	Description
void	applySnapshot(@NonNull Snapshot.State snapshotState)	This method is called to apply a snapshot installed by the leader.
void	createSnapshot(@NonNull ActorRef actorRef, @NonNull Optional<OutputStream> installSnapshotStream)	This method is called by the RaftActor when a snapshot needs to be created.
@NonNull Snapshot.State	deserializeSnapshot(@NonNull ByteSource snapshotBytes)	This method is called to de-serialize snapshot data that was previously serialized via createSnapshot(akka.actor.ActorRef, java.util.Optional<java.io.OutputStream>) to a State instance.

Method Detail

createSnapshot

void createSnapshot(@NonNull ActorRef actorRef,
                    @NonNull Optional<OutputStream> installSnapshotStream)

This method is called by the RaftActor when a snapshot needs to be created. The implementation should send a CaptureSnapshotReply to the given actor.

Parameters:

actorRef - the actor to which to respond

installSnapshotStream - Optional OutputStream that is present if the snapshot is to also be installed on a follower. The implementation must serialize its state to the OutputStream and return the installSnapshotStream instance in the CaptureSnapshotReply along with the snapshot State instance. The snapshot State is serialized directly to the snapshot store while the OutputStream is used to send the state data to follower(s) in chunks. The deserializeSnapshot(com.google.common.io.ByteSource) method is used to convert the serialized data back to a State instance on the follower end. The serialization for snapshot install is passed off so the cost of serialization is not charged to the raft actor's thread.

applySnapshot

void applySnapshot(@NonNull Snapshot.State snapshotState)

This method is called to apply a snapshot installed by the leader.

Parameters:

snapshotState - a snapshot of the state of the actor

deserializeSnapshot

@NonNull Snapshot.State deserializeSnapshot(@NonNull ByteSource snapshotBytes)
                                     throws IOException

This method is called to de-serialize snapshot data that was previously serialized via createSnapshot(akka.actor.ActorRef, java.util.Optional<java.io.OutputStream>) to a State instance.

Parameters:

snapshotBytes - the ByteSource containing the serialized data

Returns:

the converted snapshot State

Throws:

IOException - if an error occurs accessing the ByteSource or de-serializing