package org.opendaylight.controller.cluster.raft;
-import java.util.concurrent.atomic.AtomicLong;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.Preconditions;
+import com.google.common.base.Stopwatch;
+import java.util.concurrent.TimeUnit;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import org.opendaylight.controller.cluster.raft.behaviors.LeaderInstallSnapshotState;
/**
- * The state of the followers log as known by the Leader
+ * The state of the followers log as known by the Leader.
+ *
+ * @author Moiz Raja
+ * @author Thomas Pantelis
*/
-public interface FollowerLogInformation {
+public final class FollowerLogInformation {
+ public static final long NO_INDEX = -1;
+
+ private final Stopwatch stopwatch = Stopwatch.createUnstarted();
+
+ private final RaftActorContext context;
+
+ private long nextIndex;
+
+ private long matchIndex;
+
+ private long lastReplicatedIndex = -1L;
+
+ private final Stopwatch lastReplicatedStopwatch = Stopwatch.createUnstarted();
+
+ private short payloadVersion = -1;
+
+ // Assume the HELIUM_VERSION version initially for backwards compatibility until we obtain the follower's
+ // actual version via AppendEntriesReply. Although we no longer support the Helium version, a pre-Boron
+ // follower will not have the version field in AppendEntriesReply so it will be set to 0 which is
+ // HELIUM_VERSION.
+ private short raftVersion = RaftVersions.HELIUM_VERSION;
+
+ private final PeerInfo peerInfo;
+
+ private LeaderInstallSnapshotState installSnapshotState;
+
+ private long slicedLogEntryIndex = NO_INDEX;
/**
- * Increment the value of the nextIndex
- * @return
+ * Constructs an instance.
+ *
+ * @param peerInfo the associated PeerInfo of the follower.
+ * @param matchIndex the initial match index.
+ * @param context the RaftActorContext.
*/
- public long incrNextIndex();
+ @VisibleForTesting
+ FollowerLogInformation(final PeerInfo peerInfo, final long matchIndex, final RaftActorContext context) {
+ this.nextIndex = context.getCommitIndex();
+ this.matchIndex = matchIndex;
+ this.context = context;
+ this.peerInfo = Preconditions.checkNotNull(peerInfo);
+ }
/**
- * Decrement the value of the nextIndex
- * @return
+ * Constructs an instance with no matching index.
+ *
+ * @param peerInfo the associated PeerInfo of the follower.
+ * @param context the RaftActorContext.
*/
- public long decrNextIndex();
+ public FollowerLogInformation(final PeerInfo peerInfo, final RaftActorContext context) {
+ this(peerInfo, NO_INDEX, context);
+ }
/**
+ * Increments the value of the follower's next index.
*
- * @param nextIndex
+ * @return the new value of nextIndex.
*/
- void setNextIndex(long nextIndex);
+ @VisibleForTesting
+ long incrNextIndex() {
+ return nextIndex++;
+ }
/**
- * Increment the value of the matchIndex
- * @return
+ * Decrements the value of the follower's next index.
+ *
+ * @return true if the next index was decremented, ie it was previously >= 0, false otherwise.
*/
- public long incrMatchIndex();
+ public boolean decrNextIndex() {
+ if (nextIndex < 0) {
+ return false;
+ }
- public void setMatchIndex(long matchIndex);
+ nextIndex--;
+ return true;
+ }
/**
- * The identifier of the follower
- * This could simply be the url of the remote actor
+ * Sets the index of the follower's next log entry.
+ *
+ * @param nextIndex the new index.
+ * @return true if the new index differed from the current index and the current index was updated, false
+ * otherwise.
*/
- public String getId();
+ @SuppressWarnings("checkstyle:hiddenField")
+ public boolean setNextIndex(final long nextIndex) {
+ if (this.nextIndex != nextIndex) {
+ this.nextIndex = nextIndex;
+ return true;
+ }
+
+ return false;
+ }
/**
- * for each server, index of the next log entry
- * to send to that server (initialized to leader
- * last log index + 1)
+ * Increments the value of the follower's match index.
+ *
+ * @return the new value of matchIndex.
*/
- public AtomicLong getNextIndex();
+ public long incrMatchIndex() {
+ return matchIndex++;
+ }
/**
- * for each server, index of highest log entry
- * known to be replicated on server
- * (initialized to 0, increases monotonically)
+ * Sets the index of the follower's highest log entry.
+ *
+ * @param matchIndex the new index.
+ * @return true if the new index differed from the current index and the current index was updated, false
+ * otherwise.
*/
- public AtomicLong getMatchIndex();
+ @SuppressWarnings("checkstyle:hiddenField")
+ public boolean setMatchIndex(final long matchIndex) {
+ // If the new match index is the index of the entry currently being sliced, then we know slicing is complete
+ // and the follower received the entry and responded so clear the slicedLogEntryIndex
+ if (isLogEntrySlicingInProgress() && slicedLogEntryIndex == matchIndex) {
+ slicedLogEntryIndex = NO_INDEX;
+ }
+
+ if (this.matchIndex != matchIndex) {
+ this.matchIndex = matchIndex;
+ return true;
+ }
+
+ return false;
+ }
+ /**
+ * Returns the identifier of the follower.
+ *
+ * @return the identifier of the follower.
+ */
+ public String getId() {
+ return peerInfo.getId();
+ }
+
+ /**
+ * Returns the index of the next log entry to send to the follower.
+ *
+ * @return index of the follower's next log entry.
+ */
+ public long getNextIndex() {
+ return nextIndex;
+ }
+
+ /**
+ * Returns the index of highest log entry known to be replicated on the follower.
+ *
+ * @return the index of highest log entry.
+ */
+ public long getMatchIndex() {
+ return matchIndex;
+ }
+
+ /**
+ * Checks if the follower is active by comparing the time of the last activity with the election time out. The
+ * follower is active if some activity has occurred for the follower within the election time out interval.
+ *
+ * @return true if follower is active, false otherwise.
+ */
+ public boolean isFollowerActive() {
+ if (peerInfo.getVotingState() == VotingState.VOTING_NOT_INITIALIZED) {
+ return false;
+ }
+
+ long elapsed = stopwatch.elapsed(TimeUnit.MILLISECONDS);
+ return stopwatch.isRunning()
+ && elapsed <= context.getConfigParams().getElectionTimeOutInterval().toMillis();
+ }
+
+ /**
+ * Marks the follower as active. This should be called when some activity has occurred for the follower.
+ */
+ public void markFollowerActive() {
+ if (stopwatch.isRunning()) {
+ stopwatch.reset();
+ }
+ stopwatch.start();
+ }
+
+ /**
+ * Marks the follower as inactive. This should only be called from unit tests.
+ */
+ @VisibleForTesting
+ public void markFollowerInActive() {
+ if (stopwatch.isRunning()) {
+ stopwatch.stop();
+ }
+ }
+
+ /**
+ * Returns the time since the last activity occurred for the follower.
+ *
+ * @return time in nanoseconds since the last activity from the follower.
+ */
+ public long nanosSinceLastActivity() {
+ return stopwatch.elapsed(TimeUnit.NANOSECONDS);
+ }
+
+ /**
+ * This method checks if the next replicate message can be sent to the follower. This is an optimization to avoid
+ * sending duplicate message too frequently if the last replicate message was sent and no reply has been received
+ * yet within the current heart beat interval
+ *
+ * @return true if it is OK to replicate, false otherwise
+ */
+ public boolean okToReplicate() {
+ if (peerInfo.getVotingState() == VotingState.VOTING_NOT_INITIALIZED) {
+ return false;
+ }
+
+ // Return false if we are trying to send duplicate data before the heartbeat interval
+ if (getNextIndex() == lastReplicatedIndex && lastReplicatedStopwatch.elapsed(TimeUnit.MILLISECONDS)
+ < context.getConfigParams().getHeartBeatInterval().toMillis()) {
+ return false;
+ }
+
+ resetLastReplicated();
+ return true;
+ }
+
+ private void resetLastReplicated() {
+ lastReplicatedIndex = getNextIndex();
+ if (lastReplicatedStopwatch.isRunning()) {
+ lastReplicatedStopwatch.reset();
+ }
+ lastReplicatedStopwatch.start();
+ }
+
+ /**
+ * Returns the log entry payload data version of the follower.
+ *
+ * @return the payload data version.
+ */
+ public short getPayloadVersion() {
+ return payloadVersion;
+ }
+
+ /**
+ * Sets the payload data version of the follower.
+ *
+ * @param payloadVersion the payload data version.
+ */
+ public void setPayloadVersion(final short payloadVersion) {
+ this.payloadVersion = payloadVersion;
+ }
+
+ /**
+ * Returns the the raft version of the follower.
+ *
+ * @return the raft version of the follower.
+ */
+ public short getRaftVersion() {
+ return raftVersion;
+ }
+
+ /**
+ * Sets the raft version of the follower.
+ *
+ * @param raftVersion the raft version.
+ */
+ public void setRaftVersion(final short raftVersion) {
+ this.raftVersion = raftVersion;
+ }
+
+ /**
+ * Returns the LeaderInstallSnapshotState for the in progress install snapshot.
+ *
+ * @return the LeaderInstallSnapshotState if a snapshot install is in progress, null otherwise.
+ */
+ @Nullable
+ public LeaderInstallSnapshotState getInstallSnapshotState() {
+ return installSnapshotState;
+ }
+
+ /**
+ * Sets the LeaderInstallSnapshotState when an install snapshot is initiated.
+ *
+ * @param state the LeaderInstallSnapshotState
+ */
+ public void setLeaderInstallSnapshotState(@Nonnull final LeaderInstallSnapshotState state) {
+ if (this.installSnapshotState == null) {
+ this.installSnapshotState = Preconditions.checkNotNull(state);
+ }
+ }
+
+ /**
+ * Clears the LeaderInstallSnapshotState when an install snapshot is complete.
+ */
+ public void clearLeaderInstallSnapshotState() {
+ Preconditions.checkState(installSnapshotState != null);
+ installSnapshotState.close();
+ installSnapshotState = null;
+ }
+
+ /**
+ * Sets the index of the log entry whose payload size exceeds the maximum size for a single message and thus
+ * needs to be sliced into smaller chunks.
+ *
+ * @param index the log entry index or NO_INDEX to clear it
+ */
+ public void setSlicedLogEntryIndex(final long index) {
+ slicedLogEntryIndex = index;
+ }
+
+ /**
+ * Return whether or not log entry slicing is currently in progress.
+ *
+ * @return true if slicing is currently in progress, false otherwise
+ */
+ public boolean isLogEntrySlicingInProgress() {
+ return slicedLogEntryIndex != NO_INDEX;
+ }
+ @Override
+ public String toString() {
+ return "FollowerLogInformation [id=" + getId() + ", nextIndex=" + nextIndex + ", matchIndex=" + matchIndex
+ + ", lastReplicatedIndex=" + lastReplicatedIndex + ", votingState=" + peerInfo.getVotingState()
+ + ", stopwatch=" + stopwatch.elapsed(TimeUnit.MILLISECONDS) + ", followerTimeoutMillis="
+ + context.getConfigParams().getElectionTimeOutInterval().toMillis() + "]";
+ }
}
Code Review / controller.git / blobdiff