import akka.japi.Procedure;
import akka.persistence.SnapshotSelectionCriteria;
-import com.google.protobuf.ByteString;
-import org.opendaylight.controller.cluster.DataPersistenceProvider;
+import com.google.common.annotations.VisibleForTesting;
+import java.util.List;
import org.opendaylight.controller.cluster.raft.base.messages.CaptureSnapshot;
import org.opendaylight.controller.cluster.raft.base.messages.SendInstallSnapshot;
import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
public class SnapshotManager implements SnapshotState {
-
private final SnapshotState IDLE = new Idle();
- private final SnapshotState CAPTURING = new Capturing();
private final SnapshotState PERSISTING = new Persisting();
private final SnapshotState CREATING = new Creating();
private SnapshotState currentState = IDLE;
private CaptureSnapshot captureSnapshot;
+ private long lastSequenceNumber = -1;
+
+ private Procedure<Void> createSnapshotProcedure;
+
+ private Snapshot applySnapshot;
+ private Procedure<byte[]> applySnapshotProcedure;
public SnapshotManager(RaftActorContext context, Logger logger) {
this.context = context;
}
@Override
- public void create(Procedure<Void> callback) {
- currentState.create(callback);
+ public void apply(Snapshot snapshot) {
+ currentState.apply(snapshot);
}
@Override
- public void persist(DataPersistenceProvider persistenceProvider, byte[] snapshotBytes,
- RaftActorBehavior currentBehavior, long totalMemory) {
- currentState.persist(persistenceProvider, snapshotBytes, currentBehavior, totalMemory);
+ public void persist(byte[] snapshotBytes, RaftActorBehavior currentBehavior, long totalMemory) {
+ currentState.persist(snapshotBytes, currentBehavior, totalMemory);
}
@Override
- public void commit(DataPersistenceProvider persistenceProvider, long sequenceNumber) {
- currentState.commit(persistenceProvider, sequenceNumber);
+ public void commit(long sequenceNumber, RaftActorBehavior currentBehavior) {
+ currentState.commit(sequenceNumber, currentBehavior);
}
@Override
return currentState.trimLog(desiredTrimIndex, currentBehavior);
}
+ public void setCreateSnapshotCallable(Procedure<Void> createSnapshotProcedure) {
+ this.createSnapshotProcedure = createSnapshotProcedure;
+ }
+
+ public void setApplySnapshotProcedure(Procedure<byte[]> applySnapshotProcedure) {
+ this.applySnapshotProcedure = applySnapshotProcedure;
+ }
+
+ public long getLastSequenceNumber() {
+ return lastSequenceNumber;
+ }
+
+ @VisibleForTesting
+ public CaptureSnapshot getCaptureSnapshot() {
+ return captureSnapshot;
+ }
+
private boolean hasFollowers(){
return context.getPeerAddresses().keySet().size() > 0;
}
@Override
public boolean isCapturing() {
- return false;
+ return true;
}
@Override
}
@Override
- public void create(Procedure<Void> callback) {
- LOG.debug("create should not be called in state {}", this);
+ public void apply(Snapshot snapshot) {
+ LOG.debug("apply should not be called in state {}", this);
}
@Override
- public void persist(DataPersistenceProvider persistenceProvider, byte[] snapshotBytes,
- RaftActorBehavior currentBehavior, long totalMemory) {
+ public void persist(byte[] snapshotBytes, RaftActorBehavior currentBehavior, long totalMemory) {
LOG.debug("persist should not be called in state {}", this);
}
@Override
- public void commit(DataPersistenceProvider persistenceProvider, long sequenceNumber) {
+ public void commit(long sequenceNumber, RaftActorBehavior currentBehavior) {
LOG.debug("commit should not be called in state {}", this);
}
private class Idle extends AbstractSnapshotState {
+ @Override
+ public boolean isCapturing() {
+ return false;
+ }
+
private boolean capture(ReplicatedLogEntry lastLogEntry, long replicatedToAllIndex, String targetFollower) {
TermInformationReader lastAppliedTermInfoReader =
lastAppliedTermInformationReader.init(context.getReplicatedLog(), context.getLastApplied(),
long newReplicatedToAllTerm = replicatedToAllTermInfoReader.getTerm();
// send a CaptureSnapshot to self to make the expensive operation async.
- captureSnapshot = new CaptureSnapshot(lastLogEntry.getIndex(),
- lastLogEntry.getTerm(), lastAppliedIndex, lastAppliedTerm,
- newReplicatedToAllIndex, newReplicatedToAllTerm, targetFollower!=null);
- SnapshotManager.this.currentState = CAPTURING;
+ List<ReplicatedLogEntry> unAppliedEntries = context.getReplicatedLog().getFrom(lastAppliedIndex + 1);
- if(targetFollower != null){
- LOG.info("{}: Initiating snapshot capture {}", persistenceId(), captureSnapshot);
+ long lastLogEntryIndex = lastAppliedIndex;
+ long lastLogEntryTerm = lastAppliedTerm;
+ if(lastLogEntry != null) {
+ lastLogEntryIndex = lastLogEntry.getIndex();
+ lastLogEntryTerm = lastLogEntry.getTerm();
} else {
+ LOG.warn("Capturing Snapshot : lastLogEntry is null. Using lastAppliedIndex {} and lastAppliedTerm {} instead.",
+ lastAppliedIndex, lastAppliedTerm);
+ }
+
+ captureSnapshot = new CaptureSnapshot(lastLogEntryIndex,
+ lastLogEntryTerm, lastAppliedIndex, lastAppliedTerm,
+ newReplicatedToAllIndex, newReplicatedToAllTerm, unAppliedEntries, targetFollower != null);
+
+ if(captureSnapshot.isInstallSnapshotInitiated()) {
LOG.info("{}: Initiating snapshot capture {} to install on {}",
persistenceId(), captureSnapshot, targetFollower);
+ } else {
+ LOG.info("{}: Initiating snapshot capture {}", persistenceId(), captureSnapshot);
}
- context.getActor().tell(captureSnapshot, context.getActor());
+ lastSequenceNumber = context.getPersistenceProvider().getLastSequenceNumber();
+
+ LOG.debug("lastSequenceNumber prior to capture: {}", lastSequenceNumber);
+
+ SnapshotManager.this.currentState = CREATING;
+
+ try {
+ createSnapshotProcedure.apply(null);
+ } catch (Exception e) {
+ SnapshotManager.this.currentState = IDLE;
+ LOG.error("Error creating snapshot", e);
+ return false;
+ }
return true;
}
}
@Override
- public String toString() {
- return "Idle";
- }
+ public void apply(Snapshot snapshot) {
+ applySnapshot = snapshot;
- @Override
- public long trimLog(long desiredTrimIndex, RaftActorBehavior currentBehavior) {
- return doTrimLog(desiredTrimIndex, currentBehavior);
- }
- }
+ lastSequenceNumber = context.getPersistenceProvider().getLastSequenceNumber();
- private class Capturing extends AbstractSnapshotState {
+ LOG.debug("lastSequenceNumber prior to persisting applied snapshot: {}", lastSequenceNumber);
- @Override
- public boolean isCapturing() {
- return true;
- }
+ context.getPersistenceProvider().saveSnapshot(snapshot);
- @Override
- public void create(Procedure<Void> callback) {
- try {
- callback.apply(null);
- SnapshotManager.this.currentState = CREATING;
- } catch (Exception e) {
- LOG.error("Unexpected error occurred", e);
- }
+ SnapshotManager.this.currentState = PERSISTING;
}
@Override
public String toString() {
- return "Capturing";
+ return "Idle";
}
+ @Override
+ public long trimLog(long desiredTrimIndex, RaftActorBehavior currentBehavior) {
+ return doTrimLog(desiredTrimIndex, currentBehavior);
+ }
}
private class Creating extends AbstractSnapshotState {
@Override
- public boolean isCapturing() {
- return true;
- }
-
- @Override
- public void persist(DataPersistenceProvider persistenceProvider, byte[] snapshotBytes,
- RaftActorBehavior currentBehavior, long totalMemory) {
+ public void persist(byte[] snapshotBytes, RaftActorBehavior currentBehavior, long totalMemory) {
// create a snapshot object from the state provided and save it
// when snapshot is saved async, SaveSnapshotSuccess is raised.
- Snapshot sn = Snapshot.create(snapshotBytes,
- context.getReplicatedLog().getFrom(captureSnapshot.getLastAppliedIndex() + 1),
+ Snapshot snapshot = Snapshot.create(snapshotBytes,
+ captureSnapshot.getUnAppliedEntries(),
captureSnapshot.getLastIndex(), captureSnapshot.getLastTerm(),
- captureSnapshot.getLastAppliedIndex(), captureSnapshot.getLastAppliedTerm());
+ captureSnapshot.getLastAppliedIndex(), captureSnapshot.getLastAppliedTerm(),
+ context.getTermInformation().getCurrentTerm(),
+ context.getTermInformation().getVotedFor());
- persistenceProvider.saveSnapshot(sn);
+ context.getPersistenceProvider().saveSnapshot(snapshot);
- LOG.info("{}: Persisting of snapshot done:{}", persistenceId(), sn.getLogMessage());
+ LOG.info("{}: Persisting of snapshot done: {}", persistenceId(), snapshot);
long dataThreshold = totalMemory *
context.getConfigParams().getSnapshotDataThresholdPercentage() / 100;
- if (context.getReplicatedLog().dataSize() > dataThreshold) {
+ boolean dataSizeThresholdExceeded = context.getReplicatedLog().dataSize() > dataThreshold;
+ boolean logSizeExceededSnapshotBatchCount =
+ context.getReplicatedLog().size() >= context.getConfigParams().getSnapshotBatchCount();
+
+ if (dataSizeThresholdExceeded || logSizeExceededSnapshotBatchCount) {
if(LOG.isDebugEnabled()) {
- LOG.debug("{}: dataSize {} exceeds dataThreshold {} - doing snapshotPreCommit with index {}",
- persistenceId(), context.getReplicatedLog().dataSize(), dataThreshold,
- captureSnapshot.getLastAppliedIndex());
+ if(dataSizeThresholdExceeded) {
+ LOG.debug("{}: log data size {} exceeds the memory threshold {} - doing snapshotPreCommit with index {}",
+ context.getId(), context.getReplicatedLog().dataSize(), dataThreshold,
+ captureSnapshot.getLastAppliedIndex());
+ } else {
+ LOG.debug("{}: log size {} exceeds the snapshot batch count {} - doing snapshotPreCommit with index {}",
+ context.getId(), context.getReplicatedLog().size(),
+ context.getConfigParams().getSnapshotBatchCount(), captureSnapshot.getLastAppliedIndex());
+ }
}
- // if memory is less, clear the log based on lastApplied.
- // this could/should only happen if one of the followers is down
- // as normally we keep removing from the log when its replicated to all.
+ // We either exceeded the memory threshold or the log size exceeded the snapshot batch
+ // count so, to keep the log memory footprint in check, clear the log based on lastApplied.
+ // This could/should only happen if one of the followers is down as normally we keep
+ // removing from the log as entries are replicated to all.
context.getReplicatedLog().snapshotPreCommit(captureSnapshot.getLastAppliedIndex(),
captureSnapshot.getLastAppliedTerm());
context.getReplicatedLog().getSnapshotTerm());
}
- LOG.info("{}: Removed in-memory snapshotted entries, adjusted snaphsotIndex:{} " +
- "and term:{}", persistenceId(), captureSnapshot.getLastAppliedIndex(),
- captureSnapshot.getLastAppliedTerm());
+ LOG.info("{}: Removed in-memory snapshotted entries, adjusted snaphsotIndex: {} " +
+ "and term: {}", context.getId(), context.getReplicatedLog().getSnapshotIndex(),
+ context.getReplicatedLog().getSnapshotTerm());
if (context.getId().equals(currentBehavior.getLeaderId())
&& captureSnapshot.isInstallSnapshotInitiated()) {
// this would be call straight to the leader and won't initiate in serialization
- currentBehavior.handleMessage(context.getActor(), new SendInstallSnapshot(
- ByteString.copyFrom(snapshotBytes)));
+ currentBehavior.handleMessage(context.getActor(), new SendInstallSnapshot(snapshot));
}
captureSnapshot = null;
private class Persisting extends AbstractSnapshotState {
@Override
- public void commit(DataPersistenceProvider persistenceProvider, long sequenceNumber) {
- context.getReplicatedLog().snapshotCommit();
- persistenceProvider.deleteSnapshots(new SnapshotSelectionCriteria(
+ public void commit(long sequenceNumber, RaftActorBehavior currentBehavior) {
+ LOG.debug("Snapshot success sequence number:", sequenceNumber);
+
+ if(applySnapshot != null) {
+ try {
+ applySnapshotProcedure.apply(applySnapshot.getState());
+
+ //clears the followers log, sets the snapshot index to ensure adjusted-index works
+ context.setReplicatedLog(ReplicatedLogImpl.newInstance(applySnapshot, context, currentBehavior));
+ context.setLastApplied(applySnapshot.getLastAppliedIndex());
+ context.setCommitIndex(applySnapshot.getLastAppliedIndex());
+ } catch (Exception e) {
+ LOG.error("Error applying snapshot", e);
+ }
+ } else {
+ context.getReplicatedLog().snapshotCommit();
+ }
+
+ context.getPersistenceProvider().deleteSnapshots(new SnapshotSelectionCriteria(
sequenceNumber - context.getConfigParams().getSnapshotBatchCount(), 43200000));
- persistenceProvider.deleteMessages(sequenceNumber);
+ context.getPersistenceProvider().deleteMessages(lastSequenceNumber);
+ lastSequenceNumber = -1;
+ applySnapshot = null;
SnapshotManager.this.currentState = IDLE;
}
@Override
public void rollback() {
- context.getReplicatedLog().snapshotRollback();
-
- LOG.info("{}: Replicated Log rolled back. Snapshot will be attempted in the next cycle." +
- "snapshotIndex:{}, snapshotTerm:{}, log-size:{}", persistenceId(),
- context.getReplicatedLog().getSnapshotIndex(),
- context.getReplicatedLog().getSnapshotTerm(),
- context.getReplicatedLog().size());
+ // Nothing to rollback if we're applying a snapshot from the leader.
+ if(applySnapshot == null) {
+ context.getReplicatedLog().snapshotRollback();
+
+ LOG.info("{}: Replicated Log rolled back. Snapshot will be attempted in the next cycle." +
+ "snapshotIndex:{}, snapshotTerm:{}, log-size:{}", persistenceId(),
+ context.getReplicatedLog().getSnapshotIndex(),
+ context.getReplicatedLog().getSnapshotTerm(),
+ context.getReplicatedLog().size());
+ }
+ lastSequenceNumber = -1;
+ applySnapshot = null;
SnapshotManager.this.currentState = IDLE;
}
this.term = -1L;
if (!hasFollowers) {
if(lastLogEntry != null) {
+ // since we have persisted the last-log-entry to persistent journal before the capture,
+ // we would want to snapshot from this entry.
index = lastLogEntry.getIndex();
term = lastLogEntry.getTerm();
}