X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-akka-raft%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fraft%2FFollowerLogInformation.java;h=3952b386b2498a6e2fecf56d6f5a1cb3f4dda8fc;hp=f3de9835385eb0880bb567402f5bb493f8ad3a76;hb=1b1360ac337d23b9a586f62616eb278c3065eef0;hpb=fe4049d34de103016d11f3a9050853c6380646d3

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/FollowerLogInformation.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/FollowerLogInformation.java
index f3de983538..3952b386b2 100644
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/FollowerLogInformation.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/FollowerLogInformation.java
@@ -8,58 +8,339 @@
 
 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() + "]";
+    }
 }