import java.util.Queue;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
+import javax.annotation.Nullable;
import org.opendaylight.controller.cluster.raft.ServerConfigurationPayload.ServerInfo;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
+import org.opendaylight.controller.cluster.raft.base.messages.SnapshotComplete;
import org.opendaylight.controller.cluster.raft.behaviors.AbstractLeader;
import org.opendaylight.controller.cluster.raft.messages.AddServer;
import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
return true;
} else if(message instanceof ApplyState) {
return onApplyState((ApplyState) message, raftActor);
+ } else if(message instanceof SnapshotComplete) {
+ currentOperationState.onSnapshotComplete(raftActor);
+ return false;
} else {
return false;
}
void onUnInitializedFollowerSnapshotReply(RaftActor raftActor, UnInitializedFollowerSnapshotReply reply);
void onApplyState(RaftActor raftActor, ApplyState applyState);
+
+ void onSnapshotComplete(RaftActor raftActor);
}
/**
LOG.debug("onApplyState was called in state {}", this);
}
+ @Override
+ public void onSnapshotComplete(RaftActor raftActor) {
+ }
+
protected void persistNewServerConfiguration(RaftActor raftActor, ServerOperationContext<?> operationContext){
Collection<PeerInfo> peers = raftContext.getPeers();
List<ServerInfo> newConfig = new ArrayList<>(peers.size() + 1);
newConfig.add(new ServerInfo(raftContext.getId(), true));
- LOG.debug("{}: New server configuration : {}", raftContext.getId(), newConfig);
+ LOG.debug("{}: Persisting new server configuration : {}", raftContext.getId(), newConfig);
ServerConfigurationPayload payload = new ServerConfigurationPayload(newConfig);
raftActor.persistData(operationContext.getClientRequestor(), operationContext.getContextId(), payload);
currentOperationState = new Persisting(operationContext);
+
+ sendReply(raftActor, operationContext, ServerChangeStatus.OK);
}
protected void operationComplete(RaftActor raftActor, ServerOperationContext<?> operationContext,
- ServerChangeStatus status) {
-
- LOG.debug("{}: Returning {} for operation {}", raftContext.getId(), status, operationContext.getOperation());
-
- operationContext.getClientRequestor().tell(operationContext.newReply(status, raftActor.getLeaderId()),
- raftActor.self());
+ @Nullable ServerChangeStatus replyStatus) {
+ if(replyStatus != null) {
+ sendReply(raftActor, operationContext, replyStatus);
+ }
currentOperationState = IDLE;
}
}
+ private void sendReply(RaftActor raftActor, ServerOperationContext<?> operationContext,
+ ServerChangeStatus status) {
+ LOG.debug("{}: Returning {} for operation {}", raftContext.getId(), status, operationContext.getOperation());
+
+ operationContext.getClientRequestor().tell(operationContext.newReply(status, raftActor.getLeaderId()),
+ raftActor.self());
+ }
+
@Override
public String toString() {
return getClass().getSimpleName();
LOG.info("{}: {} has been successfully replicated to a majority of followers",
applyState.getReplicatedLogEntry().getData());
- operationComplete(raftActor, operationContext, ServerChangeStatus.OK);
+ operationComplete(raftActor, operationContext, null);
}
}
}
AddServerContext getAddServerContext() {
return addServerContext;
}
+
+ Cancellable newInstallSnapshotTimer(RaftActor raftActor) {
+ return raftContext.getActorSystem().scheduler().scheduleOnce(
+ new FiniteDuration(((raftContext.getConfigParams().getElectionTimeOutInterval().toMillis()) * 2),
+ TimeUnit.MILLISECONDS), raftContext.getActor(),
+ new FollowerCatchUpTimeout(addServerContext.getOperation().getNewServerId()),
+ raftContext.getActorSystem().dispatcher(), raftContext.getActor());
+ }
+
+ void handleOnFollowerCatchupTimeout(RaftActor raftActor, FollowerCatchUpTimeout followerTimeout) {
+ String serverId = followerTimeout.getNewServerId();
+
+ LOG.debug("{}: onFollowerCatchupTimeout for new server {}", raftContext.getId(), serverId);
+
+ // cleanup
+ raftContext.removePeer(serverId);
+
+ boolean isLeader = raftActor.isLeader();
+ if(isLeader) {
+ AbstractLeader leader = (AbstractLeader) raftActor.getCurrentBehavior();
+ leader.removeFollower(serverId);
+ }
+
+ operationComplete(raftActor, getAddServerContext(),
+ isLeader ? ServerChangeStatus.TIMEOUT : ServerChangeStatus.NO_LEADER);
+ }
}
/**
@Override
public void initiate(RaftActor raftActor) {
AbstractLeader leader = (AbstractLeader) raftActor.getCurrentBehavior();
-
AddServer addServer = getAddServerContext().getOperation();
LOG.debug("{}: Initiating {}", raftContext.getId(), addServer);
+ if(raftContext.getPeerInfo(addServer.getNewServerId()) != null) {
+ operationComplete(raftActor, getAddServerContext(), ServerChangeStatus.ALREADY_EXISTS);
+ return;
+ }
+
VotingState votingState = addServer.isVotingMember() ? VotingState.VOTING_NOT_INITIALIZED :
VotingState.NON_VOTING;
raftContext.addToPeers(addServer.getNewServerId(), addServer.getNewServerAddress(), votingState);
leader.addFollower(addServer.getNewServerId());
if(votingState == VotingState.VOTING_NOT_INITIALIZED){
- LOG.debug("{}: Leader sending initiate capture snapshot to new follower {}", raftContext.getId(),
- addServer.getNewServerId());
-
- leader.initiateCaptureSnapshot(addServer.getNewServerId());
-
// schedule the install snapshot timeout timer
- Cancellable installSnapshotTimer = raftContext.getActorSystem().scheduler().scheduleOnce(
- new FiniteDuration(((raftContext.getConfigParams().getElectionTimeOutInterval().toMillis()) * 2),
- TimeUnit.MILLISECONDS), raftContext.getActor(),
- new FollowerCatchUpTimeout(addServer.getNewServerId()),
- raftContext.getActorSystem().dispatcher(), raftContext.getActor());
-
- currentOperationState = new InstallingSnapshot(getAddServerContext(), installSnapshotTimer);
+ Cancellable installSnapshotTimer = newInstallSnapshotTimer(raftActor);
+ if(leader.initiateCaptureSnapshot(addServer.getNewServerId())) {
+ LOG.debug("{}: Initiating capture snapshot for new server {}", raftContext.getId(),
+ addServer.getNewServerId());
+
+ currentOperationState = new InstallingSnapshot(getAddServerContext(), installSnapshotTimer);
+ } else {
+ LOG.debug("{}: Snapshot already in progress - waiting for completion", raftContext.getId());
+
+ currentOperationState = new WaitingForPriorSnapshotComplete(getAddServerContext(),
+ installSnapshotTimer);
+ }
} else {
LOG.debug("{}: New follower is non-voting - directly persisting new server configuration",
raftContext.getId());
@Override
public void onFollowerCatchupTimeout(RaftActor raftActor, FollowerCatchUpTimeout followerTimeout) {
- String serverId = followerTimeout.getNewServerId();
-
- LOG.debug("{}: onFollowerCatchupTimeout: {}", raftContext.getId(), serverId);
-
- AbstractLeader leader = (AbstractLeader) raftActor.getCurrentBehavior();
-
- // cleanup
- raftContext.removePeer(serverId);
- leader.removeFollower(serverId);
-
- LOG.warn("{}: Timeout occured for new server {} while installing snapshot", raftContext.getId(), serverId);
+ handleOnFollowerCatchupTimeout(raftActor, followerTimeout);
- operationComplete(raftActor, getAddServerContext(), ServerChangeStatus.TIMEOUT);
+ LOG.warn("{}: Timeout occured for new server {} while installing snapshot", raftContext.getId(),
+ followerTimeout.getNewServerId());
}
@Override
// Sanity check to guard against receiving an UnInitializedFollowerSnapshotReply from a prior
// add server operation that timed out.
- if(getAddServerContext().getOperation().getNewServerId().equals(followerId)) {
+ if(getAddServerContext().getOperation().getNewServerId().equals(followerId) && raftActor.isLeader()) {
AbstractLeader leader = (AbstractLeader) raftActor.getCurrentBehavior();
raftContext.getPeerInfo(followerId).setVotingState(VotingState.VOTING);
leader.updateMinReplicaCount();
persistNewServerConfiguration(raftActor, getAddServerContext());
installSnapshotTimer.cancel();
+ } else {
+ LOG.debug("{}: Dropping UnInitializedFollowerSnapshotReply for server {}: {}",
+ raftContext.getId(), followerId,
+ !raftActor.isLeader() ? "not leader" : "server Id doesn't match");
}
}
}
+ /**
+ * The AddServer operation state for when there is a snapshot already in progress. When the current
+ * snapshot completes, it initiates an install snapshot.
+ */
+ private class WaitingForPriorSnapshotComplete extends AddServerState {
+ private final Cancellable snapshotTimer;
+
+ WaitingForPriorSnapshotComplete(AddServerContext addServerContext, Cancellable snapshotTimer) {
+ super(addServerContext);
+ this.snapshotTimer = Preconditions.checkNotNull(snapshotTimer);
+ }
+
+ @Override
+ public void onSnapshotComplete(RaftActor raftActor) {
+ LOG.debug("{}: onSnapshotComplete", raftContext.getId());
+
+ if(!raftActor.isLeader()) {
+ LOG.debug("{}: No longer the leader", raftContext.getId());
+ return;
+ }
+
+ AbstractLeader leader = (AbstractLeader) raftActor.getCurrentBehavior();
+ if(leader.initiateCaptureSnapshot(getAddServerContext().getOperation().getNewServerId())) {
+ LOG.debug("{}: Initiating capture snapshot for new server {}", raftContext.getId(),
+ getAddServerContext().getOperation().getNewServerId());
+
+ currentOperationState = new InstallingSnapshot(getAddServerContext(),
+ newInstallSnapshotTimer(raftActor));
+
+ snapshotTimer.cancel();
+ }
+ }
+
+ @Override
+ public void onFollowerCatchupTimeout(RaftActor raftActor, FollowerCatchUpTimeout followerTimeout) {
+ handleOnFollowerCatchupTimeout(raftActor, followerTimeout);
+
+ LOG.warn("{}: Timeout occured for new server {} while waiting for prior snapshot to complete",
+ raftContext.getId(), followerTimeout.getNewServerId());
+ }
+ }
+
/**
* Stores context information for a server operation.
*