import com.google.common.base.Optional;
import com.google.common.base.Stopwatch;
import com.google.protobuf.ByteString;
+import java.io.Serializable;
+import java.util.Map;
import org.opendaylight.controller.cluster.DataPersistenceProvider;
import org.opendaylight.controller.cluster.common.actor.AbstractUntypedPersistentActor;
+import org.opendaylight.controller.cluster.notifications.RoleChanged;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyLogEntries;
import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
import org.opendaylight.controller.cluster.raft.behaviors.AbstractRaftActorBehavior;
import org.opendaylight.controller.cluster.raft.behaviors.Follower;
import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
-import org.opendaylight.controller.cluster.raft.client.messages.AddRaftPeer;
import org.opendaylight.controller.cluster.raft.client.messages.FindLeader;
import org.opendaylight.controller.cluster.raft.client.messages.FindLeaderReply;
-import org.opendaylight.controller.cluster.raft.client.messages.RemoveRaftPeer;
import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
import org.opendaylight.controller.protobuff.messages.cluster.raft.AppendEntriesMessages;
-import java.io.Serializable;
-import java.util.Map;
-
/**
* RaftActor encapsulates a state machine that needs to be kept synchronized
* in a cluster. It implements the RAFT algorithm as described in the paper
private int currentRecoveryBatchCount;
+
+
public RaftActor(String id, Map<String, String> peerAddresses) {
this(id, peerAddresses, Optional.<ConfigParams>absent());
}
deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(), scala.Long.MaxValue()));
onRecoveryComplete();
+
+ RaftActorBehavior oldBehavior = currentBehavior;
currentBehavior = new Follower(context);
- onStateChanged();
+ handleBehaviorChange(oldBehavior, currentBehavior);
}
}
}
replicatedLog.lastIndex(), replicatedLog.snapshotIndex,
replicatedLog.snapshotTerm, replicatedLog.size());
+ RaftActorBehavior oldBehavior = currentBehavior;
currentBehavior = new Follower(context);
- onStateChanged();
+ handleBehaviorChange(oldBehavior, currentBehavior);
}
@Override public void handleCommand(Object message) {
context.getReplicatedLog().getSnapshotTerm(),
context.getReplicatedLog().size());
- } else if (message instanceof AddRaftPeer){
-
- // FIXME : Do not add raft peers like this.
- // When adding a new Peer we have to ensure that the a majority of
- // the peers know about the new Peer. Doing it this way may cause
- // a situation where multiple Leaders may emerge
- AddRaftPeer arp = (AddRaftPeer)message;
- context.addToPeers(arp.getName(), arp.getAddress());
-
- } else if (message instanceof RemoveRaftPeer){
-
- RemoveRaftPeer rrp = (RemoveRaftPeer)message;
- context.removePeer(rrp.getName());
-
} else if (message instanceof CaptureSnapshot) {
LOG.info("CaptureSnapshot received by actor");
CaptureSnapshot cs = (CaptureSnapshot)message;
RaftActorBehavior oldBehavior = currentBehavior;
currentBehavior = currentBehavior.handleMessage(getSender(), message);
- if(oldBehavior != currentBehavior){
- onStateChanged();
- }
-
- onLeaderChanged(oldBehavior.getLeaderId(), currentBehavior.getLeaderId());
+ handleBehaviorChange(oldBehavior, currentBehavior);
}
}
- public java.util.Set<String> getPeers() {
+ private void handleBehaviorChange(RaftActorBehavior oldBehavior, RaftActorBehavior currentBehavior) {
+ if (oldBehavior != currentBehavior){
+ onStateChanged();
+ }
- return context.getPeerAddresses().keySet();
- }
+ String oldBehaviorLeaderId = oldBehavior == null? null : oldBehavior.getLeaderId();
+ String oldBehaviorState = oldBehavior == null? null : oldBehavior.state().name();
- protected String getReplicatedLogState() {
- return "snapshotIndex=" + context.getReplicatedLog().getSnapshotIndex()
- + ", snapshotTerm=" + context.getReplicatedLog().getSnapshotTerm()
- + ", im-mem journal size=" + context.getReplicatedLog().size();
- }
+ // it can happen that the state has not changed but the leader has changed.
+ onLeaderChanged(oldBehaviorLeaderId, currentBehavior.getLeaderId());
+ if (getRoleChangeNotifier().isPresent() &&
+ (oldBehavior == null || (oldBehavior.state() != currentBehavior.state()))) {
+ getRoleChangeNotifier().get().tell(
+ new RoleChanged(getId(), oldBehaviorState , currentBehavior.state().name()),
+ getSelf());
+ }
+ }
/**
* When a derived RaftActor needs to persist something it must call
* @param identifier
* @param data
*/
- protected void persistData(ActorRef clientActor, String identifier,
- Payload data) {
+ protected void persistData(final ActorRef clientActor, final String identifier,
+ final Payload data) {
ReplicatedLogEntry replicatedLogEntry = new ReplicatedLogImplEntry(
context.getReplicatedLog().lastIndex() + 1,
LOG.debug("Persist data {}", replicatedLogEntry);
}
+ final RaftActorContext raftContext = getRaftActorContext();
+
replicatedLog
- .appendAndPersist(clientActor, identifier, replicatedLogEntry);
- }
+ .appendAndPersist(replicatedLogEntry, new Procedure<ReplicatedLogEntry>() {
+ @Override
+ public void apply(ReplicatedLogEntry replicatedLogEntry) throws Exception {
+ if(!hasFollowers()){
+ // Increment the Commit Index and the Last Applied values
+ raftContext.setCommitIndex(replicatedLogEntry.getIndex());
+ raftContext.setLastApplied(replicatedLogEntry.getIndex());
+
+ // Apply the state immediately
+ applyState(clientActor, identifier, data);
+
+ // Send a ApplyLogEntries message so that we write the fact that we applied
+ // the state to durable storage
+ self().tell(new ApplyLogEntries((int) replicatedLogEntry.getIndex()), self());
+
+ // Check if the "real" snapshot capture has been initiated. If no then do the fake snapshot
+ if(!hasSnapshotCaptureInitiated){
+ raftContext.getReplicatedLog().snapshotPreCommit(raftContext.getLastApplied(),
+ raftContext.getTermInformation().getCurrentTerm());
+ raftContext.getReplicatedLog().snapshotCommit();
+ } else {
+ LOG.debug("Skipping fake snapshotting for {} because real snapshotting is in progress", getId());
+ }
+ } else if (clientActor != null) {
+ // Send message for replication
+ currentBehavior.handleMessage(getSelf(),
+ new Replicate(clientActor, identifier,
+ replicatedLogEntry)
+ );
+ }
+
+ }
+ }); }
protected String getId() {
return context.getId();
protected abstract DataPersistenceProvider persistence();
+ /**
+ * Notifier Actor for this RaftActor to notify when a role change happens
+ * @return ActorRef - ActorRef of the notifier or Optional.absent if none.
+ */
+ protected abstract Optional<ActorRef> getRoleChangeNotifier();
+
protected void onLeaderChanged(String oldLeader, String newLeader){};
private void trimPersistentData(long sequenceNumber) {
hasSnapshotCaptureInitiated = false;
}
+ protected boolean hasFollowers(){
+ return getRaftActorContext().getPeerAddresses().keySet().size() > 0;
+ }
+
private class ReplicatedLogImpl extends AbstractReplicatedLogImpl {
+ private static final int DATA_SIZE_DIVIDER = 5;
+ private long dataSizeSinceLastSnapshot = 0;
+
public ReplicatedLogImpl(Snapshot snapshot) {
super(snapshot.getLastAppliedIndex(), snapshot.getLastAppliedTerm(),
snapshot.getUnAppliedEntries());
@Override public void apply(DeleteEntries param)
throws Exception {
//FIXME : Doing nothing for now
+ dataSize = 0;
+ for(ReplicatedLogEntry entry : journal){
+ dataSize += entry.size();
+ }
}
});
}
@Override public void appendAndPersist(
final ReplicatedLogEntry replicatedLogEntry) {
- appendAndPersist(null, null, replicatedLogEntry);
+ appendAndPersist(replicatedLogEntry, null);
}
- public void appendAndPersist(final ActorRef clientActor,
- final String identifier,
- final ReplicatedLogEntry replicatedLogEntry) {
+ @Override
+ public int dataSize() {
+ return dataSize;
+ }
+
+ public void appendAndPersist(
+ final ReplicatedLogEntry replicatedLogEntry,
+ final Procedure<ReplicatedLogEntry> callback) {
if(LOG.isDebugEnabled()) {
LOG.debug("Append log entry and persist {} ", replicatedLogEntry);
new Procedure<ReplicatedLogEntry>() {
@Override
public void apply(ReplicatedLogEntry evt) throws Exception {
+ int logEntrySize = replicatedLogEntry.size();
+
+ dataSize += logEntrySize;
+ long dataSizeForCheck = dataSize;
+
+ dataSizeSinceLastSnapshot += logEntrySize;
+ long journalSize = lastIndex()+1;
+
+ if(!hasFollowers()) {
+ // When we do not have followers we do not maintain an in-memory log
+ // due to this the journalSize will never become anything close to the
+ // snapshot batch count. In fact will mostly be 1.
+ // Similarly since the journal's dataSize depends on the entries in the
+ // journal the journal's dataSize will never reach a value close to the
+ // memory threshold.
+ // By maintaining the dataSize outside the journal we are tracking essentially
+ // what we have written to the disk however since we no longer are in
+ // need of doing a snapshot just for the sake of freeing up memory we adjust
+ // the real size of data by the DATA_SIZE_DIVIDER so that we do not snapshot as often
+ // as if we were maintaining a real snapshot
+ dataSizeForCheck = dataSizeSinceLastSnapshot / DATA_SIZE_DIVIDER;
+ }
+
+ long dataThreshold = Runtime.getRuntime().totalMemory() *
+ getRaftActorContext().getConfigParams().getSnapshotDataThresholdPercentage() / 100;
+
// when a snaphsot is being taken, captureSnapshot != null
if (hasSnapshotCaptureInitiated == false &&
- journal.size() % context.getConfigParams().getSnapshotBatchCount() == 0) {
+ ( journalSize % context.getConfigParams().getSnapshotBatchCount() == 0 ||
+ dataSizeForCheck > dataThreshold)) {
+
+ dataSizeSinceLastSnapshot = 0;
LOG.info("Initiating Snapshot Capture..");
long lastAppliedIndex = -1;
long lastAppliedTerm = -1;
ReplicatedLogEntry lastAppliedEntry = get(context.getLastApplied());
- if (lastAppliedEntry != null) {
+ if (!hasFollowers()) {
+ lastAppliedIndex = replicatedLogEntry.getIndex();
+ lastAppliedTerm = replicatedLogEntry.getTerm();
+ } else if (lastAppliedEntry != null) {
lastAppliedIndex = lastAppliedEntry.getIndex();
lastAppliedTerm = lastAppliedEntry.getTerm();
}
null);
hasSnapshotCaptureInitiated = true;
}
- // Send message for replication
- if (clientActor != null) {
- currentBehavior.handleMessage(getSelf(),
- new Replicate(clientActor, identifier,
- replicatedLogEntry)
- );
+ if(callback != null){
+ callback.apply(replicatedLogEntry);
}
}
}
}
static class DeleteEntries implements Serializable {
+ private static final long serialVersionUID = 1L;
private final int fromIndex;
-
public DeleteEntries(int fromIndex) {
this.fromIndex = fromIndex;
}
}
static class UpdateElectionTerm implements Serializable {
+ private static final long serialVersionUID = 1L;
private final long currentTerm;
private final String votedFor;
protected RaftActorBehavior getCurrentBehavior() {
return currentBehavior;
}
+
}
Code Review / controller.git / blobdiff