import akka.serialization.Serialization;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
-import com.google.common.cache.Cache;
-import com.google.common.cache.CacheBuilder;
-import com.google.common.cache.RemovalCause;
-import com.google.common.cache.RemovalListener;
-import com.google.common.cache.RemovalNotification;
+import com.google.common.base.Stopwatch;
+import java.util.HashMap;
+import java.util.Iterator;
import java.util.LinkedList;
+import java.util.Map;
import java.util.Queue;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import org.opendaylight.controller.cluster.datastore.compat.BackwardsCompatibleThreePhaseCommitCohort;
+import org.opendaylight.controller.cluster.datastore.messages.AbortTransactionReply;
import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
import org.opendaylight.controller.cluster.datastore.messages.BatchedModificationsReply;
import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransactionReply;
import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
+import org.opendaylight.controller.cluster.datastore.messages.ReadyLocalTransaction;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
import org.opendaylight.controller.cluster.datastore.modification.Modification;
-import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
import org.opendaylight.controller.md.sal.common.api.data.TransactionCommitFailedException;
+import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
import org.slf4j.Logger;
/**
*
* @author Thomas Pantelis
*/
-public class ShardCommitCoordinator {
+class ShardCommitCoordinator {
// Interface hook for unit tests to replace or decorate the DOMStoreThreePhaseCommitCohorts.
public interface CohortDecorator {
ShardDataTreeCohort decorate(String transactionID, ShardDataTreeCohort actual);
}
- private final Cache<String, CohortEntry> cohortCache;
+ private final Map<String, CohortEntry> cohortCache = new HashMap<>();
private CohortEntry currentCohortEntry;
private final ShardDataTree dataTree;
- private final Queue<CohortEntry> queuedCohortEntries;
+ // We use a LinkedList here to avoid synchronization overhead with concurrent queue impls
+ // since this should only be accessed on the shard's dispatcher.
+ private final Queue<CohortEntry> queuedCohortEntries = new LinkedList<>();
private int queueCapacity;
private final String name;
- private final RemovalListener<String, CohortEntry> cacheRemovalListener =
- new RemovalListener<String, CohortEntry>() {
- @Override
- public void onRemoval(RemovalNotification<String, CohortEntry> notification) {
- if(notification.getCause() == RemovalCause.EXPIRED) {
- log.warn("{}: Transaction {} was timed out of the cache", name, notification.getKey());
- }
- }
- };
+ private final long cacheExpiryTimeoutInMillis;
// This is a hook for unit tests to replace or decorate the DOMStoreThreePhaseCommitCohorts.
private CohortDecorator cohortDecorator;
private ReadyTransactionReply readyTransactionReply;
- public ShardCommitCoordinator(ShardDataTree dataTree,
- long cacheExpiryTimeoutInSec, int queueCapacity, ActorRef shardActor, Logger log, String name) {
+ ShardCommitCoordinator(ShardDataTree dataTree,
+ long cacheExpiryTimeoutInMillis, int queueCapacity, Logger log, String name) {
this.queueCapacity = queueCapacity;
this.log = log;
this.name = name;
this.dataTree = Preconditions.checkNotNull(dataTree);
+ this.cacheExpiryTimeoutInMillis = cacheExpiryTimeoutInMillis;
+ }
- cohortCache = CacheBuilder.newBuilder().expireAfterAccess(cacheExpiryTimeoutInSec, TimeUnit.SECONDS).
- removalListener(cacheRemovalListener).build();
-
- // We use a LinkedList here to avoid synchronization overhead with concurrent queue impls
- // since this should only be accessed on the shard's dispatcher.
- queuedCohortEntries = new LinkedList<>();
+ int getQueueSize() {
+ return queuedCohortEntries.size();
}
- public void setQueueCapacity(int queueCapacity) {
+ void setQueueCapacity(int queueCapacity) {
this.queueCapacity = queueCapacity;
}
return readyTransactionReply;
}
+ private boolean queueCohortEntry(CohortEntry cohortEntry, ActorRef sender, Shard shard) {
+ if(queuedCohortEntries.size() < queueCapacity) {
+ queuedCohortEntries.offer(cohortEntry);
+
+ log.debug("{}: Enqueued transaction {}, queue size {}", name, cohortEntry.getTransactionID(),
+ queuedCohortEntries.size());
+
+ return true;
+ } else {
+ cohortCache.remove(cohortEntry.getTransactionID());
+
+ RuntimeException ex = new RuntimeException(
+ String.format("%s: Could not enqueue transaction %s - the maximum commit queue"+
+ " capacity %d has been reached.",
+ name, cohortEntry.getTransactionID(), queueCapacity));
+ log.error(ex.getMessage());
+ sender.tell(new Status.Failure(ex), shard.self());
+ return false;
+ }
+ }
+
/**
* This method is called to ready a transaction that was prepared by ShardTransaction actor. It caches
* the prepared cohort entry for the given transactions ID in preparation for the subsequent 3-phase commit.
+ *
+ * @param ready the ForwardedReadyTransaction message to process
+ * @param sender the sender of the message
+ * @param shard the transaction's shard actor
*/
- public void handleForwardedReadyTransaction(ForwardedReadyTransaction ready, ActorRef sender, Shard shard) {
+ void handleForwardedReadyTransaction(ForwardedReadyTransaction ready, ActorRef sender, Shard shard) {
log.debug("{}: Readying transaction {}, client version {}", name,
ready.getTransactionID(), ready.getTxnClientVersion());
- CohortEntry cohortEntry = new CohortEntry(ready.getTransactionID(), ready.getCohort(),
- (MutableCompositeModification) ready.getModification());
+ CohortEntry cohortEntry = new CohortEntry(ready.getTransactionID(), ready.getCohort());
cohortCache.put(ready.getTransactionID(), cohortEntry);
+ if(!queueCohortEntry(cohortEntry, sender, shard)) {
+ return;
+ }
+
if(ready.getTxnClientVersion() < DataStoreVersions.LITHIUM_VERSION) {
// Return our actor path as we'll handle the three phase commit except if the Tx client
// version < Helium-1 version which means the Tx was initiated by a base Helium version node.
* DOMStoreWriteTransaction, one is created. The batched modifications are applied to the write Tx. If
* the BatchedModifications is ready to commit then a DOMStoreThreePhaseCommitCohort is created.
*
- * @param batched the BatchedModifications
- * @param shardActor the transaction's shard actor
- *
- * @throws ExecutionException if an error occurs loading the cache
+ * @param batched the BatchedModifications message to process
+ * @param sender the sender of the message
+ * @param shard the transaction's shard actor
*/
- boolean handleBatchedModifications(BatchedModifications batched, ActorRef sender, Shard shard)
- throws ExecutionException {
- CohortEntry cohortEntry = cohortCache.getIfPresent(batched.getTransactionID());
+ void handleBatchedModifications(BatchedModifications batched, ActorRef sender, Shard shard) {
+ CohortEntry cohortEntry = cohortCache.get(batched.getTransactionID());
if(cohortEntry == null) {
cohortEntry = new CohortEntry(batched.getTransactionID(),
dataTree.newReadWriteTransaction(batched.getTransactionID(),
cohortEntry.applyModifications(batched.getModifications());
if(batched.isReady()) {
+ if(cohortEntry.getLastBatchedModificationsException() != null) {
+ cohortCache.remove(cohortEntry.getTransactionID());
+ throw cohortEntry.getLastBatchedModificationsException();
+ }
+
+ if(cohortEntry.getTotalBatchedModificationsReceived() != batched.getTotalMessagesSent()) {
+ cohortCache.remove(cohortEntry.getTransactionID());
+ throw new IllegalStateException(String.format(
+ "The total number of batched messages received %d does not match the number sent %d",
+ cohortEntry.getTotalBatchedModificationsReceived(), batched.getTotalMessagesSent()));
+ }
+
+ if(!queueCohortEntry(cohortEntry, sender, shard)) {
+ return;
+ }
+
if(log.isDebugEnabled()) {
log.debug("{}: Readying Tx {}, client version {}", name,
batched.getTransactionID(), batched.getVersion());
} else {
sender.tell(new BatchedModificationsReply(batched.getModifications().size()), shard.self());
}
+ }
+
+ /**
+ * This method handles {@link ReadyLocalTransaction} message. All transaction modifications have
+ * been prepared beforehand by the sender and we just need to drive them through into the dataTree.
+ *
+ * @param message the ReadyLocalTransaction message to process
+ * @param sender the sender of the message
+ * @param shard the transaction's shard actor
+ */
+ void handleReadyLocalTransaction(ReadyLocalTransaction message, ActorRef sender, Shard shard) {
+ final ShardDataTreeCohort cohort = new SimpleShardDataTreeCohort(dataTree, message.getModification(),
+ message.getTransactionID());
+ final CohortEntry cohortEntry = new CohortEntry(message.getTransactionID(), cohort);
+ cohortCache.put(message.getTransactionID(), cohortEntry);
+ cohortEntry.setDoImmediateCommit(message.isDoCommitOnReady());
+
+ if(!queueCohortEntry(cohortEntry, sender, shard)) {
+ return;
+ }
- return batched.isReady();
+ log.debug("{}: Applying local modifications for Tx {}", name, message.getTransactionID());
+
+ if (message.isDoCommitOnReady()) {
+ cohortEntry.setReplySender(sender);
+ cohortEntry.setShard(shard);
+ handleCanCommit(cohortEntry);
+ } else {
+ sender.tell(readyTransactionReply(shard), shard.self());
+ }
}
private void handleCanCommit(CohortEntry cohortEntry) {
String transactionID = cohortEntry.getTransactionID();
- if(log.isDebugEnabled()) {
- log.debug("{}: Processing canCommit for transaction {} for shard {}",
- name, transactionID, cohortEntry.getShard().self().path());
- }
+ cohortEntry.updateLastAccessTime();
if(currentCohortEntry != null) {
- // There's already a Tx commit in progress - attempt to queue this entry to be
- // committed after the current Tx completes.
- log.debug("{}: Transaction {} is already in progress - queueing transaction {}",
- name, currentCohortEntry.getTransactionID(), transactionID);
+ // There's already a Tx commit in progress so we can't process this entry yet - but it's in the
+ // queue and will get processed after all prior entries complete.
- if(queuedCohortEntries.size() < queueCapacity) {
- queuedCohortEntries.offer(cohortEntry);
- } else {
- removeCohortEntry(transactionID);
-
- RuntimeException ex = new RuntimeException(
- String.format("%s: Could not enqueue transaction %s - the maximum commit queue"+
- " capacity %d has been reached.",
- name, transactionID, queueCapacity));
- log.error(ex.getMessage());
- cohortEntry.getReplySender().tell(new Status.Failure(ex), cohortEntry.getShard().self());
+ if(log.isDebugEnabled()) {
+ log.debug("{}: Commit for Tx {} already in progress - skipping canCommit for {} for now",
+ name, currentCohortEntry.getTransactionID(), transactionID);
}
- } else {
- // No Tx commit currently in progress - make this the current entry and proceed with
- // canCommit.
- cohortEntry.updateLastAccessTime();
- currentCohortEntry = cohortEntry;
- doCanCommit(cohortEntry);
+ return;
+ }
+
+ // No Tx commit currently in progress - check if this entry is the next one in the queue, If so make
+ // it the current entry and proceed with canCommit.
+ // Purposely checking reference equality here.
+ if(queuedCohortEntries.peek() == cohortEntry) {
+ currentCohortEntry = queuedCohortEntries.poll();
+ doCanCommit(currentCohortEntry);
+ } else {
+ if(log.isDebugEnabled()) {
+ log.debug("{}: Tx {} is the next pending canCommit - skipping {} for now",
+ name, queuedCohortEntries.peek().getTransactionID(), transactionID);
+ }
}
}
/**
* This method handles the canCommit phase for a transaction.
*
- * @param canCommit the CanCommitTransaction message
- * @param sender the actor that sent the message
+ * @param transactionID the ID of the transaction to canCommit
+ * @param sender the actor to which to send the response
* @param shard the transaction's shard actor
*/
- public void handleCanCommit(String transactionID, final ActorRef sender, final Shard shard) {
+ void handleCanCommit(String transactionID, final ActorRef sender, final Shard shard) {
// Lookup the cohort entry that was cached previously (or should have been) by
// transactionReady (via the ForwardedReadyTransaction message).
- final CohortEntry cohortEntry = cohortCache.getIfPresent(transactionID);
+ final CohortEntry cohortEntry = cohortCache.get(transactionID);
if(cohortEntry == null) {
// Either canCommit was invoked before ready(shouldn't happen) or a long time passed
// between canCommit and ready and the entry was expired from the cache.
}
private void doCanCommit(final CohortEntry cohortEntry) {
-
boolean canCommit = false;
try {
- // We block on the future here so we don't have to worry about possibly accessing our
- // state on a different thread outside of our dispatcher. Also, the data store
- // currently uses a same thread executor anyway.
- canCommit = cohortEntry.getCohort().canCommit().get();
+ canCommit = cohortEntry.canCommit();
+
+ log.debug("{}: canCommit for {}: {}", name, cohortEntry.getTransactionID(), canCommit);
if(cohortEntry.isDoImmediateCommit()) {
if(canCommit) {
CanCommitTransactionReply.NO.toSerializable(), cohortEntry.getShard().self());
}
} catch (Exception e) {
- log.debug("{}: An exception occurred during canCommit: {}", name, e);
+ log.debug("{}: An exception occurred during canCommit", name, e);
Throwable failure = e;
if(e instanceof ExecutionException) {
// normally fail since we ensure only one concurrent 3-phase commit.
try {
- // We block on the future here so we don't have to worry about possibly accessing our
- // state on a different thread outside of our dispatcher. Also, the data store
- // currently uses a same thread executor anyway.
- cohortEntry.getCohort().preCommit().get();
+ cohortEntry.preCommit();
cohortEntry.getShard().continueCommit(cohortEntry);
return success;
}
+ /**
+ * This method handles the preCommit and commit phases for a transaction.
+ *
+ * @param transactionID the ID of the transaction to commit
+ * @param sender the actor to which to send the response
+ * @param shard the transaction's shard actor
+ * @return true if the transaction was successfully prepared, false otherwise.
+ */
boolean handleCommit(final String transactionID, final ActorRef sender, final Shard shard) {
// Get the current in-progress cohort entry in the commitCoordinator if it corresponds to
// this transaction.
return false;
}
+ cohortEntry.setReplySender(sender);
return doCommit(cohortEntry);
}
+ void handleAbort(final String transactionID, final ActorRef sender, final Shard shard) {
+ CohortEntry cohortEntry = getCohortEntryIfCurrent(transactionID);
+ if(cohortEntry != null) {
+ // We don't remove the cached cohort entry here (ie pass false) in case the Tx was
+ // aborted during replication in which case we may still commit locally if replication
+ // succeeds.
+ currentTransactionComplete(transactionID, false);
+ } else {
+ cohortEntry = getAndRemoveCohortEntry(transactionID);
+ }
+
+ if(cohortEntry == null) {
+ return;
+ }
+
+ log.debug("{}: Aborting transaction {}", name, transactionID);
+
+ final ActorRef self = shard.getSelf();
+ try {
+ cohortEntry.abort();
+
+ shard.getShardMBean().incrementAbortTransactionsCount();
+
+ if(sender != null) {
+ sender.tell(new AbortTransactionReply().toSerializable(), self);
+ }
+ } catch (Exception e) {
+ log.error("{}: An exception happened during abort", name, e);
+
+ if(sender != null) {
+ sender.tell(new akka.actor.Status.Failure(e), self);
+ }
+ }
+ }
+
/**
* Returns the cohort entry for the Tx commit currently in progress if the given transaction ID
* matches the current entry.
}
public CohortEntry getAndRemoveCohortEntry(String transactionID) {
- CohortEntry cohortEntry = cohortCache.getIfPresent(transactionID);
- cohortCache.invalidate(transactionID);
- return cohortEntry;
- }
-
- public void removeCohortEntry(String transactionID) {
- cohortCache.invalidate(transactionID);
+ return cohortCache.remove(transactionID);
}
public boolean isCurrentTransaction(String transactionID) {
*/
public void currentTransactionComplete(String transactionID, boolean removeCohortEntry) {
if(removeCohortEntry) {
- removeCohortEntry(transactionID);
+ cohortCache.remove(transactionID);
}
if(isCurrentTransaction(transactionID)) {
- // Dequeue the next cohort entry waiting in the queue.
- currentCohortEntry = queuedCohortEntries.poll();
- if(currentCohortEntry != null) {
- currentCohortEntry.updateLastAccessTime();
- doCanCommit(currentCohortEntry);
+ currentCohortEntry = null;
+
+ log.debug("{}: currentTransactionComplete: {}", name, transactionID);
+
+ maybeProcessNextCohortEntry();
+ }
+ }
+
+ private void maybeProcessNextCohortEntry() {
+ // Check if there's a next cohort entry waiting in the queue and if it is ready to commit. Also
+ // clean out expired entries.
+ Iterator<CohortEntry> iter = queuedCohortEntries.iterator();
+ while(iter.hasNext()) {
+ CohortEntry next = iter.next();
+ if(next.isReadyToCommit()) {
+ if(currentCohortEntry == null) {
+ if(log.isDebugEnabled()) {
+ log.debug("{}: Next entry to canCommit {}", name, next);
+ }
+
+ iter.remove();
+ currentCohortEntry = next;
+ currentCohortEntry.updateLastAccessTime();
+ doCanCommit(currentCohortEntry);
+ }
+
+ break;
+ } else if(next.isExpired(cacheExpiryTimeoutInMillis)) {
+ log.warn("{}: canCommit for transaction {} was not received within {} ms - entry removed from cache",
+ name, next.getTransactionID(), cacheExpiryTimeoutInMillis);
+ } else if(!next.isAborted()) {
+ break;
}
+
+ iter.remove();
+ cohortCache.remove(next.getTransactionID());
}
}
+ void cleanupExpiredCohortEntries() {
+ maybeProcessNextCohortEntry();
+ }
+
@VisibleForTesting
void setCohortDecorator(CohortDecorator cohortDecorator) {
this.cohortDecorator = cohortDecorator;
}
-
static class CohortEntry {
private final String transactionID;
private ShardDataTreeCohort cohort;
private final ReadWriteShardDataTreeTransaction transaction;
+ private RuntimeException lastBatchedModificationsException;
private ActorRef replySender;
private Shard shard;
- private long lastAccessTime;
private boolean doImmediateCommit;
+ private final Stopwatch lastAccessTimer = Stopwatch.createStarted();
+ private int totalBatchedModificationsReceived;
+ private boolean aborted;
CohortEntry(String transactionID, ReadWriteShardDataTreeTransaction transaction) {
this.transaction = Preconditions.checkNotNull(transaction);
this.transactionID = transactionID;
}
- CohortEntry(String transactionID, ShardDataTreeCohort cohort,
- MutableCompositeModification compositeModification) {
+ CohortEntry(String transactionID, ShardDataTreeCohort cohort) {
this.transactionID = transactionID;
this.cohort = cohort;
this.transaction = null;
}
void updateLastAccessTime() {
- lastAccessTime = System.currentTimeMillis();
- }
-
- long getLastAccessTime() {
- return lastAccessTime;
+ lastAccessTimer.reset();
+ lastAccessTimer.start();
}
String getTransactionID() {
return transactionID;
}
- ShardDataTreeCohort getCohort() {
- return cohort;
+ DataTreeCandidate getCandidate() {
+ return cohort.getCandidate();
+ }
+
+ int getTotalBatchedModificationsReceived() {
+ return totalBatchedModificationsReceived;
+ }
+
+ RuntimeException getLastBatchedModificationsException() {
+ return lastBatchedModificationsException;
}
void applyModifications(Iterable<Modification> modifications) {
- for (Modification modification : modifications) {
- modification.apply(transaction.getSnapshot());
+ totalBatchedModificationsReceived++;
+ if(lastBatchedModificationsException == null) {
+ for (Modification modification : modifications) {
+ try {
+ modification.apply(transaction.getSnapshot());
+ } catch (RuntimeException e) {
+ lastBatchedModificationsException = e;
+ throw e;
+ }
+ }
}
}
+ boolean canCommit() throws InterruptedException, ExecutionException {
+ // We block on the future here (and also preCommit(), commit(), abort()) so we don't have to worry
+ // about possibly accessing our state on a different thread outside of our dispatcher.
+ // TODO: the ShardDataTreeCohort returns immediate Futures anyway which begs the question - why
+ // bother even returning Futures from ShardDataTreeCohort if we have to treat them synchronously
+ // anyway?. The Futures are really a remnant from when we were using the InMemoryDataBroker.
+ return cohort.canCommit().get();
+ }
+
+ void preCommit() throws InterruptedException, ExecutionException {
+ cohort.preCommit().get();
+ }
+
+ void commit() throws InterruptedException, ExecutionException {
+ cohort.commit().get();
+ }
+
+ void abort() throws InterruptedException, ExecutionException {
+ aborted = true;
+ cohort.abort().get();
+ }
+
void ready(CohortDecorator cohortDecorator, boolean doImmediateCommit) {
Preconditions.checkState(cohort == null, "cohort was already set");
}
}
+ boolean isReadyToCommit() {
+ return replySender != null;
+ }
+
+ boolean isExpired(long expireTimeInMillis) {
+ return lastAccessTimer.elapsed(TimeUnit.MILLISECONDS) >= expireTimeInMillis;
+ }
+
boolean isDoImmediateCommit() {
return doImmediateCommit;
}
void setShard(Shard shard) {
this.shard = shard;
}
+
+
+ boolean isAborted() {
+ return aborted;
+ }
+
+ @Override
+ public String toString() {
+ StringBuilder builder = new StringBuilder();
+ builder.append("CohortEntry [transactionID=").append(transactionID).append(", doImmediateCommit=")
+ .append(doImmediateCommit).append("]");
+ return builder.toString();
+ }
}
}
Code Review / controller.git / blobdiff