import akka.actor.ActorRef;
import akka.actor.Cancellable;
+import com.google.common.base.Preconditions;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import org.opendaylight.controller.cluster.raft.ClientRequestTracker;
import org.opendaylight.controller.cluster.raft.RaftActorContext;
import org.opendaylight.controller.cluster.raft.RaftState;
import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
-import org.opendaylight.controller.cluster.raft.SerializationUtils;
-import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
import org.opendaylight.controller.cluster.raft.base.messages.ElectionTimeout;
import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
import org.opendaylight.controller.cluster.raft.messages.AppendEntriesReply;
import org.opendaylight.controller.cluster.raft.messages.RequestVote;
import org.opendaylight.controller.cluster.raft.messages.RequestVoteReply;
+import org.opendaylight.controller.cluster.raft.persisted.ApplyJournalEntries;
import org.slf4j.Logger;
import scala.concurrent.duration.FiniteDuration;
* set currentTerm = T, convert to follower (§5.1)
*/
public abstract class AbstractRaftActorBehavior implements RaftActorBehavior {
-
- protected static final ElectionTimeout ELECTION_TIMEOUT = new ElectionTimeout();
-
/**
* Information about the RaftActor whose behavior this class represents
*/
*/
private Cancellable electionCancel = null;
- /**
- *
- */
- protected String leaderId = null;
-
private long replicatedToAllIndex = -1;
private final String logName;
private final RaftState state;
- protected AbstractRaftActorBehavior(RaftActorContext context, RaftState state) {
- this.context = context;
- this.state = state;
+ AbstractRaftActorBehavior(final RaftActorContext context, final RaftState state) {
+ this.context = Preconditions.checkNotNull(context);
+ this.state = Preconditions.checkNotNull(state);
this.LOG = context.getLogger();
logName = String.format("%s (%s)", context.getId(), state);
}
+ public static RaftActorBehavior createBehavior(final RaftActorContext context, final RaftState state) {
+ switch (state) {
+ case Candidate:
+ return new Candidate(context);
+ case Follower:
+ return new Follower(context);
+ case IsolatedLeader:
+ return new IsolatedLeader(context);
+ case Leader:
+ return new Leader(context);
+ case PreLeader:
+ return new PreLeader(context);
+ default:
+ throw new IllegalArgumentException("Unhandled state " + state);
+ }
+ }
+
@Override
- public RaftState state() {
+ public final RaftState state() {
return state;
}
- public String logName() {
+ protected final String logName() {
return logName;
}
*
* @param sender The actor that sent this message
* @param appendEntries The AppendEntries message
- * @return
+ * @return a new behavior if it was changed or the current behavior
*/
protected abstract RaftActorBehavior handleAppendEntries(ActorRef sender,
AppendEntries appendEntries);
*
* @param sender
* @param appendEntries
- * @return
+ * @return a new behavior if it was changed or the current behavior
*/
protected RaftActorBehavior appendEntries(ActorRef sender,
AppendEntries appendEntries) {
sender.tell(
new AppendEntriesReply(context.getId(), currentTerm(), false,
- lastIndex(), lastTerm()), actor()
+ lastIndex(), lastTerm(), context.getPayloadVersion()), actor()
);
return this;
}
*
* @param sender The actor that sent this message
* @param appendEntriesReply The AppendEntriesReply message
- * @return
+ * @return a new behavior if it was changed or the current behavior
*/
protected abstract RaftActorBehavior handleAppendEntriesReply(ActorRef sender,
AppendEntriesReply appendEntriesReply);
*
* @param sender
* @param requestVote
- * @return
+ * @return a new behavior if it was changed or the current behavior
*/
protected RaftActorBehavior requestVote(ActorRef sender, RequestVote requestVote) {
LOG.debug("{}: In requestVote: {}", logName(), requestVote);
+ boolean grantVote = canGrantVote(requestVote);
+
+ if(grantVote) {
+ context.getTermInformation().updateAndPersist(requestVote.getTerm(), requestVote.getCandidateId());
+ }
+
+ RequestVoteReply reply = new RequestVoteReply(currentTerm(), grantVote);
+
+ LOG.debug("{}: requestVote returning: {}", logName(), reply);
+
+ sender.tell(reply, actor());
+
+ return this;
+ }
+
+ protected boolean canGrantVote(RequestVote requestVote){
boolean grantVote = false;
// Reply false if term < currentTerm (§5.1)
// If votedFor is null or candidateId, and candidate’s log is at
// least as up-to-date as receiver’s log, grant vote (§5.2, §5.4)
} else if (votedFor() == null || votedFor()
- .equals(requestVote.getCandidateId())) {
+ .equals(requestVote.getCandidateId())) {
boolean candidateLatest = false;
if (requestVote.getLastLogTerm() > lastTerm()) {
candidateLatest = true;
} else if ((requestVote.getLastLogTerm() == lastTerm())
- && requestVote.getLastLogIndex() >= lastIndex()) {
+ && requestVote.getLastLogIndex() >= lastIndex()) {
candidateLatest = true;
}
if (candidateLatest) {
grantVote = true;
- context.getTermInformation().updateAndPersist(requestVote.getTerm(),
- requestVote.getCandidateId());
}
}
-
- RequestVoteReply reply = new RequestVoteReply(currentTerm(), grantVote);
-
- LOG.debug("{}: requestVote returning: {}", logName(), reply);
-
- sender.tell(reply, actor());
-
- return this;
+ return grantVote;
}
/**
*
* @param sender The actor that sent this message
* @param requestVoteReply The RequestVoteReply message
- * @return
+ * @return a new behavior if it was changed or the current behavior
*/
protected abstract RaftActorBehavior handleRequestVoteReply(ActorRef sender,
RequestVoteReply requestVoteReply);
/**
- * Creates a random election duration
*
- * @return
+ * @return a random election duration
*/
protected FiniteDuration electionDuration() {
long variance = new Random().nextInt(context.getConfigParams().getElectionTimeVariance());
}
}
+ protected boolean canStartElection() {
+ return context.getRaftPolicy().automaticElectionsEnabled() && context.isVotingMember();
+ }
+
/**
* schedule a new election
*
- * @param interval
+ * @param interval the duration after which we should trigger a new election
*/
protected void scheduleElection(FiniteDuration interval) {
stopElection();
- // Schedule an election. When the scheduler triggers an ElectionTimeout
- // message is sent to itself
- electionCancel =
- context.getActorSystem().scheduler().scheduleOnce(interval,
- context.getActor(), ELECTION_TIMEOUT,
- context.getActorSystem().dispatcher(), context.getActor());
+ // Schedule an election. When the scheduler triggers an ElectionTimeout message is sent to itself
+ electionCancel = context.getActorSystem().scheduler().scheduleOnce(interval, context.getActor(),
+ ElectionTimeout.INSTANCE, context.getActorSystem().dispatcher(), context.getActor());
}
/**
- * Get the current term
- * @return
+ * @return the current term
*/
protected long currentTerm() {
return context.getTermInformation().getCurrentTerm();
}
/**
- * Get the candidate for whom we voted in the current term
- * @return
+ * @return the candidate for whom we voted in the current term
*/
protected String votedFor() {
return context.getTermInformation().getVotedFor();
}
/**
- * Get the actor associated with this behavior
- * @return
+ * @return the actor associated with this behavior
*/
protected ActorRef actor() {
return context.getActor();
}
/**
- * Get the term from the last entry in the log
*
- * @return
+ * @return the term from the last entry in the log
*/
protected long lastTerm() {
return context.getReplicatedLog().lastTerm();
}
/**
- * Get the index from the last entry in the log
- *
- * @return
+ * @return the index from the last entry in the log
*/
protected long lastIndex() {
return context.getReplicatedLog().lastIndex();
}
/**
- * Find the client request tracker for a specific logIndex
- *
- * @param logIndex
- * @return
- */
- protected ClientRequestTracker findClientRequestTracker(long logIndex) {
- return null;
- }
-
- /**
- * Find the client request tracker for a specific logIndex
- *
* @param logIndex
- * @return
+ * @return the client request tracker for the specified logIndex
*/
protected ClientRequestTracker removeClientRequestTracker(long logIndex) {
return null;
}
-
/**
- * Find the log index from the previous to last entry in the log
*
- * @return
+ * @return the log entry index for the given index or -1 if not found
*/
- protected long prevLogIndex(long index){
- ReplicatedLogEntry prevEntry =
- context.getReplicatedLog().get(index - 1);
- if (prevEntry != null) {
- return prevEntry.getIndex();
+ protected long getLogEntryIndex(long index){
+ if(index == context.getReplicatedLog().getSnapshotIndex()){
+ return context.getReplicatedLog().getSnapshotIndex();
+ }
+
+ ReplicatedLogEntry entry = context.getReplicatedLog().get(index);
+ if(entry != null){
+ return entry.getIndex();
}
+
return -1;
}
/**
- * Find the log term from the previous to last entry in the log
- * @return
+ * @return the log entry term for the given index or -1 if not found
*/
- protected long prevLogTerm(long index){
- ReplicatedLogEntry prevEntry =
- context.getReplicatedLog().get(index - 1);
- if (prevEntry != null) {
- return prevEntry.getTerm();
+ protected long getLogEntryTerm(long index){
+ if(index == context.getReplicatedLog().getSnapshotIndex()){
+ return context.getReplicatedLog().getSnapshotTerm();
+ }
+
+ ReplicatedLogEntry entry = context.getReplicatedLog().get(index);
+ if(entry != null){
+ return entry.getTerm();
}
+
return -1;
}
protected void applyLogToStateMachine(final long index) {
long newLastApplied = context.getLastApplied();
// Now maybe we apply to the state machine
- for (long i = context.getLastApplied() + 1;
- i < index + 1; i++) {
- ActorRef clientActor = null;
- String identifier = null;
- ClientRequestTracker tracker = removeClientRequestTracker(i);
-
- if (tracker != null) {
- clientActor = tracker.getClientActor();
- identifier = tracker.getIdentifier();
- }
- ReplicatedLogEntry replicatedLogEntry =
- context.getReplicatedLog().get(i);
+ for (long i = context.getLastApplied() + 1; i < index + 1; i++) {
+ ReplicatedLogEntry replicatedLogEntry = context.getReplicatedLog().get(i);
if (replicatedLogEntry != null) {
// Send a local message to the local RaftActor (it's derived class to be
// specific to apply the log to it's index)
- actor().tell(new ApplyState(clientActor, identifier,
- replicatedLogEntry), actor());
+
+ final ApplyState msg;
+ final ClientRequestTracker tracker = removeClientRequestTracker(i);
+ if (tracker != null) {
+ msg = new ApplyState(tracker.getClientActor(), tracker.getIdentifier(), replicatedLogEntry);
+ } else {
+ msg = new ApplyState(null, null, replicatedLogEntry);
+ }
+
+ actor().tell(msg, actor());
newLastApplied = i;
} else {
//if one index is not present in the log, no point in looping
// around as the rest wont be present either
- LOG.warn(
- "{}: Missing index {} from log. Cannot apply state. Ignoring {} to {}",
+ LOG.warn("{}: Missing index {} from log. Cannot apply state. Ignoring {} to {}",
logName(), i, i, index);
break;
}
actor().tell(new ApplyJournalEntries(context.getLastApplied()), actor());
}
- protected Object fromSerializableMessage(Object serializable){
- return SerializationUtils.fromSerializable(serializable);
- }
-
@Override
public RaftActorBehavior handleMessage(ActorRef sender, Object message) {
if (message instanceof AppendEntries) {
return requestVote(sender, (RequestVote) message);
} else if (message instanceof RequestVoteReply) {
return handleRequestVoteReply(sender, (RequestVoteReply) message);
+ } else {
+ return null;
}
- return this;
}
- @Override public String getLeaderId() {
- return leaderId;
+ @Override
+ public RaftActorBehavior switchBehavior(RaftActorBehavior behavior) {
+ return internalSwitchBehavior(behavior);
}
- protected RaftActorBehavior switchBehavior(RaftActorBehavior behavior) {
- LOG.info("{} :- Switching from behavior {} to {}", logName(), this.state(), behavior.state());
+ protected RaftActorBehavior internalSwitchBehavior(RaftState newState) {
+ return internalSwitchBehavior(createBehavior(context, newState));
+ }
+
+ protected RaftActorBehavior internalSwitchBehavior(RaftActorBehavior newBehavior) {
+ if(!context.getRaftPolicy().automaticElectionsEnabled()) {
+ return this;
+ }
+
+ LOG.info("{} :- Switching from behavior {} to {}", logName(), this.state(), newBehavior.state());
try {
close();
} catch (Exception e) {
LOG.error("{}: Failed to close behavior : {}", logName(), this.state(), e);
}
-
- return behavior;
+ return newBehavior;
}
+
protected int getMajorityVoteCount(int numPeers) {
// Votes are required from a majority of the peers including self.
// The numMajority field therefore stores a calculated value
* @param snapshotCapturedIndex
*/
protected void performSnapshotWithoutCapture(final long snapshotCapturedIndex) {
- long actualIndex = context.getSnapshotManager().trimLog(snapshotCapturedIndex, this);
+ long actualIndex = context.getSnapshotManager().trimLog(snapshotCapturedIndex);
if(actualIndex != -1){
setReplicatedToAllIndex(actualIndex);
protected String getId(){
return context.getId();
}
-
}
Code Review / controller.git / blobdiff