package org.opendaylight.controller.cluster.datastore;
-import akka.actor.ActorPath;
import akka.actor.ActorSelection;
+import akka.dispatch.Mapper;
+import akka.dispatch.OnComplete;
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.FinalizablePhantomReference;
+import com.google.common.base.FinalizableReferenceQueue;
import com.google.common.base.Optional;
-import com.google.common.util.concurrent.ListenableFuture;
-import com.google.common.util.concurrent.ListenableFutureTask;
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Lists;
+import com.google.common.util.concurrent.CheckedFuture;
+import com.google.common.util.concurrent.FutureCallback;
+import com.google.common.util.concurrent.Futures;
+import com.google.common.util.concurrent.SettableFuture;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
+import javax.annotation.concurrent.GuardedBy;
+import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
+import org.opendaylight.controller.cluster.datastore.identifiers.TransactionIdentifier;
import org.opendaylight.controller.cluster.datastore.messages.CloseTransaction;
import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
+import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
+import org.opendaylight.controller.cluster.datastore.messages.DataExists;
+import org.opendaylight.controller.cluster.datastore.messages.DataExistsReply;
import org.opendaylight.controller.cluster.datastore.messages.DeleteData;
import org.opendaylight.controller.cluster.datastore.messages.MergeData;
import org.opendaylight.controller.cluster.datastore.messages.ReadData;
import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
+import org.opendaylight.controller.cluster.datastore.messages.SerializableMessage;
import org.opendaylight.controller.cluster.datastore.messages.WriteData;
import org.opendaylight.controller.cluster.datastore.shardstrategy.ShardStrategyFactory;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
-import org.opendaylight.controller.protobuff.messages.transaction.ShardTransactionMessages.CreateTransactionReply;
+import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
-import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
+import org.opendaylight.yangtools.util.concurrent.MappingCheckedFuture;
+import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.atomic.AtomicLong;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import scala.concurrent.Future;
+import scala.concurrent.Promise;
+import scala.concurrent.duration.FiniteDuration;
/**
* TransactionProxy acts as a proxy for one or more transactions that were created on a remote shard
* </p>
*/
public class TransactionProxy implements DOMStoreReadWriteTransaction {
- public enum TransactionType {
+
+ public static enum TransactionType {
READ_ONLY,
WRITE_ONLY,
READ_WRITE
}
+ static final Mapper<Throwable, Throwable> SAME_FAILURE_TRANSFORMER =
+ new Mapper<Throwable, Throwable>() {
+ @Override
+ public Throwable apply(Throwable failure) {
+ return failure;
+ }
+ };
+
private static final AtomicLong counter = new AtomicLong();
+ private static final Logger LOG = LoggerFactory.getLogger(TransactionProxy.class);
+
+ /**
+ * Time interval in between transaction create retries.
+ */
+ private static final FiniteDuration CREATE_TX_TRY_INTERVAL =
+ FiniteDuration.create(1, TimeUnit.SECONDS);
+
+ /**
+ * Used to enqueue the PhantomReferences for read-only TransactionProxy instances. The
+ * FinalizableReferenceQueue is safe to use statically in an OSGi environment as it uses some
+ * trickery to clean up its internal thread when the bundle is unloaded.
+ */
+ private static final FinalizableReferenceQueue phantomReferenceQueue =
+ new FinalizableReferenceQueue();
+
+ /**
+ * This stores the TransactionProxyCleanupPhantomReference instances statically, This is
+ * necessary because PhantomReferences need a hard reference so they're not garbage collected.
+ * Once finalized, the TransactionProxyCleanupPhantomReference removes itself from this map
+ * and thus becomes eligible for garbage collection.
+ */
+ private static final Map<TransactionProxyCleanupPhantomReference,
+ TransactionProxyCleanupPhantomReference> phantomReferenceCache =
+ new ConcurrentHashMap<>();
+
+ /**
+ * A PhantomReference that closes remote transactions for a TransactionProxy when it's
+ * garbage collected. This is used for read-only transactions as they're not explicitly closed
+ * by clients. So the only way to detect that a transaction is no longer in use and it's safe
+ * to clean up is when it's garbage collected. It's inexact as to when an instance will be GC'ed
+ * but TransactionProxy instances should generally be short-lived enough to avoid being moved
+ * to the old generation space and thus should be cleaned up in a timely manner as the GC
+ * runs on the young generation (eden, swap1...) space much more frequently.
+ */
+ private static class TransactionProxyCleanupPhantomReference
+ extends FinalizablePhantomReference<TransactionProxy> {
+
+ private final List<ActorSelection> remoteTransactionActors;
+ private final AtomicBoolean remoteTransactionActorsMB;
+ private final ActorContext actorContext;
+ private final TransactionIdentifier identifier;
+
+ protected TransactionProxyCleanupPhantomReference(TransactionProxy referent) {
+ super(referent, phantomReferenceQueue);
+
+ // Note we need to cache the relevant fields from the TransactionProxy as we can't
+ // have a hard reference to the TransactionProxy instance itself.
+
+ remoteTransactionActors = referent.remoteTransactionActors;
+ remoteTransactionActorsMB = referent.remoteTransactionActorsMB;
+ actorContext = referent.actorContext;
+ identifier = referent.identifier;
+ }
+
+ @Override
+ public void finalizeReferent() {
+ LOG.trace("Cleaning up {} Tx actors for TransactionProxy {}",
+ remoteTransactionActors.size(), identifier);
+
+ phantomReferenceCache.remove(this);
+
+ // Access the memory barrier volatile to ensure all previous updates to the
+ // remoteTransactionActors list are visible to this thread.
+
+ if(remoteTransactionActorsMB.get()) {
+ for(ActorSelection actor : remoteTransactionActors) {
+ LOG.trace("Sending CloseTransaction to {}", actor);
+ actorContext.sendOperationAsync(actor,
+ new CloseTransaction().toSerializable());
+ }
+ }
+ }
+ }
+
+ /**
+ * Stores the remote Tx actors for each requested data store path to be used by the
+ * PhantomReference to close the remote Tx's. This is only used for read-only Tx's. The
+ * remoteTransactionActorsMB volatile serves as a memory barrier to publish updates to the
+ * remoteTransactionActors list so they will be visible to the thread accessing the
+ * PhantomReference.
+ */
+ private List<ActorSelection> remoteTransactionActors;
+ private AtomicBoolean remoteTransactionActorsMB;
+
+ /**
+ * Stores the create transaction results per shard.
+ */
+ private final Map<String, TransactionFutureCallback> txFutureCallbackMap = new HashMap<>();
+
private final TransactionType transactionType;
private final ActorContext actorContext;
- private final Map<String, ActorSelection> remoteTransactionPaths = new HashMap<>();
- private final String identifier;
- private final ExecutorService executor;
+ private final TransactionIdentifier identifier;
+ private final String transactionChainId;
private final SchemaContext schemaContext;
+ private boolean inReadyState;
+
+ public TransactionProxy(ActorContext actorContext, TransactionType transactionType) {
+ this(actorContext, transactionType, "");
+ }
+
+ public TransactionProxy(ActorContext actorContext, TransactionType transactionType,
+ String transactionChainId) {
+ this.actorContext = Preconditions.checkNotNull(actorContext,
+ "actorContext should not be null");
+ this.transactionType = Preconditions.checkNotNull(transactionType,
+ "transactionType should not be null");
+ this.schemaContext = Preconditions.checkNotNull(actorContext.getSchemaContext(),
+ "schemaContext should not be null");
+ this.transactionChainId = transactionChainId;
+
+ String memberName = actorContext.getCurrentMemberName();
+ if(memberName == null){
+ memberName = "UNKNOWN-MEMBER";
+ }
+
+ this.identifier = TransactionIdentifier.builder().memberName(memberName).counter(
+ counter.getAndIncrement()).build();
- public TransactionProxy(
- ActorContext actorContext,
- TransactionType transactionType,
- ExecutorService executor,
- SchemaContext schemaContext
- ) {
+ if(transactionType == TransactionType.READ_ONLY) {
+ // Read-only Tx's aren't explicitly closed by the client so we create a PhantomReference
+ // to close the remote Tx's when this instance is no longer in use and is garbage
+ // collected.
- this.identifier = "txn-" + counter.getAndIncrement();
- this.transactionType = transactionType;
- this.actorContext = actorContext;
- this.executor = executor;
- this.schemaContext = schemaContext;
+ remoteTransactionActors = Lists.newArrayList();
+ remoteTransactionActorsMB = new AtomicBoolean();
+ TransactionProxyCleanupPhantomReference cleanup =
+ new TransactionProxyCleanupPhantomReference(this);
+ phantomReferenceCache.put(cleanup, cleanup);
+ }
+ LOG.debug("Created txn {} of type {} on chain {}", identifier, transactionType, transactionChainId);
}
- @Override
- public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
+ @VisibleForTesting
+ List<Future<Object>> getRecordedOperationFutures() {
+ List<Future<Object>> recordedOperationFutures = Lists.newArrayList();
+ for(TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
+ TransactionContext transactionContext = txFutureCallback.getTransactionContext();
+ if(transactionContext != null) {
+ recordedOperationFutures.addAll(transactionContext.getRecordedOperationFutures());
+ }
+ }
+
+ return recordedOperationFutures;
+ }
+
+ @VisibleForTesting
+ boolean hasTransactionContext() {
+ for(TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
+ TransactionContext transactionContext = txFutureCallback.getTransactionContext();
+ if(transactionContext != null) {
+ return true;
+ }
+ }
- createTransactionIfMissing(actorContext, path);
+ return false;
+ }
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
+ @Override
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
- Callable<Optional<NormalizedNode<?,?>>> call = new Callable() {
+ Preconditions.checkState(transactionType != TransactionType.WRITE_ONLY,
+ "Read operation on write-only transaction is not allowed");
- @Override public Optional<NormalizedNode<?,?>> call() throws Exception {
- Object response = actorContext
- .executeRemoteOperation(remoteTransaction, new ReadData(path).toSerializable(),
- ActorContext.ASK_DURATION);
- if(response.getClass().equals(ReadDataReply.SERIALIZABLE_CLASS)){
- ReadDataReply reply = ReadDataReply.fromSerializable(schemaContext,path, response);
- if(reply.getNormalizedNode() == null){
- return Optional.absent();
- }
- //FIXME : A cast should not be required here ???
- return (Optional<NormalizedNode<?, ?>>) Optional.of(reply.getNormalizedNode());
- }
+ LOG.debug("Tx {} read {}", identifier, path);
- return Optional.absent();
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ return txFutureCallback.enqueueReadOperation(new ReadOperation<Optional<NormalizedNode<?, ?>>>() {
+ @Override
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> invoke(
+ TransactionContext transactionContext) {
+ return transactionContext.readData(path);
}
- };
+ });
+ }
+
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
- ListenableFutureTask<Optional<NormalizedNode<?, ?>>>
- future = ListenableFutureTask.create(call);
+ Preconditions.checkState(transactionType != TransactionType.WRITE_ONLY,
+ "Exists operation on write-only transaction is not allowed");
- executor.submit(future);
+ LOG.debug("Tx {} exists {}", identifier, path);
- return future;
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ return txFutureCallback.enqueueReadOperation(new ReadOperation<Boolean>() {
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> invoke(TransactionContext transactionContext) {
+ return transactionContext.dataExists(path);
+ }
+ });
+ }
+
+
+ private void checkModificationState() {
+ Preconditions.checkState(transactionType != TransactionType.READ_ONLY,
+ "Modification operation on read-only transaction is not allowed");
+ Preconditions.checkState(!inReadyState,
+ "Transaction is sealed - further modifications are not allowed");
}
@Override
- public void write(InstanceIdentifier path, NormalizedNode<?, ?> data) {
+ public void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
+
+ checkModificationState();
- createTransactionIfMissing(actorContext, path);
+ LOG.debug("Tx {} write {}", identifier, path);
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
- remoteTransaction.tell(new WriteData(path, data, schemaContext).toSerializable(), null);
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueModifyOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.writeData(path, data);
+ }
+ });
}
@Override
- public void merge(InstanceIdentifier path, NormalizedNode<?, ?> data) {
+ public void merge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
+
+ checkModificationState();
- createTransactionIfMissing(actorContext, path);
+ LOG.debug("Tx {} merge {}", identifier, path);
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
- remoteTransaction.tell(new MergeData(path, data, schemaContext).toSerializable(), null);
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueModifyOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.mergeData(path, data);
+ }
+ });
}
@Override
- public void delete(InstanceIdentifier path) {
+ public void delete(final YangInstanceIdentifier path) {
+
+ checkModificationState();
- createTransactionIfMissing(actorContext, path);
+ LOG.debug("Tx {} delete {}", identifier, path);
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
- remoteTransaction.tell(new DeleteData(path).toSerializable(), null);
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueModifyOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.deleteData(path);
+ }
+ });
}
@Override
public DOMStoreThreePhaseCommitCohort ready() {
- List<ActorPath> cohortPaths = new ArrayList<>();
- for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
- Object result = actorContext.executeRemoteOperation(remoteTransaction,
- new ReadyTransaction(),
- ActorContext.ASK_DURATION
- );
+ checkModificationState();
- if(result instanceof ReadyTransactionReply){
- ReadyTransactionReply reply = (ReadyTransactionReply) result;
- cohortPaths.add(reply.getCohortPath());
- }
+ inReadyState = true;
+
+ LOG.debug("Tx {} Readying {} transactions for commit", identifier,
+ txFutureCallbackMap.size());
+
+ List<Future<ActorSelection>> cohortFutures = Lists.newArrayList();
+
+ for(TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
+
+ LOG.debug("Tx {} Readying transaction for shard {} chain {}", identifier,
+ txFutureCallback.getShardName(), transactionChainId);
+
+ Future<ActorSelection> future = txFutureCallback.enqueueFutureOperation(new FutureOperation<ActorSelection>() {
+ @Override
+ public Future<ActorSelection> invoke(TransactionContext transactionContext) {
+ return transactionContext.readyTransaction();
+ }
+ });
+
+ cohortFutures.add(future);
}
- return new ThreePhaseCommitCohortProxy(actorContext, cohortPaths, identifier, executor);
+ onTransactionReady(cohortFutures);
+
+ return new ThreePhaseCommitCohortProxy(actorContext, cohortFutures,
+ identifier.toString());
+ }
+
+ /**
+ * Method for derived classes to be notified when the transaction has been readied.
+ *
+ * @param cohortFutures the cohort Futures for each shard transaction.
+ */
+ protected void onTransactionReady(List<Future<ActorSelection>> cohortFutures) {
+ }
+
+ /**
+ * Method called to send a CreateTransaction message to a shard.
+ *
+ * @param shard the shard actor to send to
+ * @param serializedCreateMessage the serialized message to send
+ * @return the response Future
+ */
+ protected Future<Object> sendCreateTransaction(ActorSelection shard,
+ Object serializedCreateMessage) {
+ return actorContext.executeOperationAsync(shard, serializedCreateMessage);
}
@Override
@Override
public void close() {
- for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
- remoteTransaction.tell(new CloseTransaction(), null);
+ for (TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
+ txFutureCallback.enqueueModifyOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.closeTransaction();
+ }
+ });
+ }
+
+ txFutureCallbackMap.clear();
+
+ if(transactionType == TransactionType.READ_ONLY) {
+ remoteTransactionActors.clear();
+ remoteTransactionActorsMB.set(true);
}
}
- private ActorSelection remoteTransactionFromIdentifier(InstanceIdentifier path){
+ private String shardNameFromIdentifier(YangInstanceIdentifier path){
+ return ShardStrategyFactory.getStrategy(path).findShard(path);
+ }
+
+ private TransactionFutureCallback getOrCreateTxFutureCallback(YangInstanceIdentifier path) {
String shardName = shardNameFromIdentifier(path);
- return remoteTransactionPaths.get(shardName);
+ TransactionFutureCallback txFutureCallback = txFutureCallbackMap.get(shardName);
+ if(txFutureCallback == null) {
+ Future<ActorSelection> findPrimaryFuture = actorContext.findPrimaryShardAsync(shardName);
+
+ final TransactionFutureCallback newTxFutureCallback =
+ new TransactionFutureCallback(shardName);
+
+ txFutureCallback = newTxFutureCallback;
+ txFutureCallbackMap.put(shardName, txFutureCallback);
+
+ findPrimaryFuture.onComplete(new OnComplete<ActorSelection>() {
+ @Override
+ public void onComplete(Throwable failure, ActorSelection primaryShard) {
+ if(failure != null) {
+ newTxFutureCallback.onComplete(failure, null);
+ } else {
+ newTxFutureCallback.setPrimaryShard(primaryShard);
+ }
+ }
+ }, actorContext.getActorSystem().dispatcher());
+ }
+
+ return txFutureCallback;
}
- private String shardNameFromIdentifier(InstanceIdentifier path){
- return ShardStrategyFactory.getStrategy(path).findShard(path);
+ public String getTransactionChainId() {
+ return transactionChainId;
+ }
+
+ protected ActorContext getActorContext() {
+ return actorContext;
+ }
+
+ /**
+ * Interfaces for transaction operations to be invoked later.
+ */
+ private static interface TransactionOperation {
+ void invoke(TransactionContext transactionContext);
+ }
+
+ /**
+ * This interface returns a Guava Future
+ */
+ private static interface ReadOperation<T> {
+ CheckedFuture<T, ReadFailedException> invoke(TransactionContext transactionContext);
+ }
+
+ /**
+ * This interface returns a Scala Future
+ */
+ private static interface FutureOperation<T> {
+ Future<T> invoke(TransactionContext transactionContext);
}
- private void createTransactionIfMissing(ActorContext actorContext, InstanceIdentifier path) {
- String shardName = ShardStrategyFactory.getStrategy(path).findShard(path);
+ /**
+ * Implements a Future OnComplete callback for a CreateTransaction message. This class handles
+ * retries, up to a limit, if the shard doesn't have a leader yet. This is done by scheduling a
+ * retry task after a short delay.
+ * <p>
+ * The end result from a completed CreateTransaction message is a TransactionContext that is
+ * used to perform transaction operations. Transaction operations that occur before the
+ * CreateTransaction completes are cache and executed once the CreateTransaction completes,
+ * successfully or not.
+ */
+ private class TransactionFutureCallback extends OnComplete<Object> {
+
+ /**
+ * The list of transaction operations to execute once the CreateTransaction completes.
+ */
+ @GuardedBy("txOperationsOnComplete")
+ private final List<TransactionOperation> txOperationsOnComplete = Lists.newArrayList();
+
+ /**
+ * The TransactionContext resulting from the CreateTransaction reply.
+ */
+ private volatile TransactionContext transactionContext;
+
+ /**
+ * The target primary shard.
+ */
+ private volatile ActorSelection primaryShard;
+
+ private volatile int createTxTries = (int) (actorContext.getDatastoreContext().
+ getShardLeaderElectionTimeout().duration().toMillis() /
+ CREATE_TX_TRY_INTERVAL.toMillis());
+
+ private final String shardName;
+
+ TransactionFutureCallback(String shardName) {
+ this.shardName = shardName;
+ }
+
+ String getShardName() {
+ return shardName;
+ }
+
+ TransactionContext getTransactionContext() {
+ return transactionContext;
+ }
+
+
+ /**
+ * Sets the target primary shard and initiates a CreateTransaction try.
+ */
+ void setPrimaryShard(ActorSelection primaryShard) {
+ LOG.debug("Tx {} Primary shard found - trying create transaction", identifier);
+
+ this.primaryShard = primaryShard;
+ tryCreateTransaction();
+ }
+
+ /**
+ * Adds a TransactionOperation to be executed after the CreateTransaction completes.
+ */
+ void addTxOperationOnComplete(TransactionOperation operation) {
+ synchronized(txOperationsOnComplete) {
+ if(transactionContext == null) {
+ LOG.debug("Tx {} Adding operation on complete {}", identifier);
+
+ txOperationsOnComplete.add(operation);
+ } else {
+ operation.invoke(transactionContext);
+ }
+ }
+ }
+
+
+ <T> Future<T> enqueueFutureOperation(final FutureOperation<T> op) {
+
+ Future<T> future;
+
+ if (transactionContext != null) {
+ future = op.invoke(transactionContext);
+ } else {
+ // The shard Tx hasn't been created yet so add the Tx operation to the Tx Future
+ // callback to be executed after the Tx is created.
+ final Promise<T> promise = akka.dispatch.Futures.promise();
+ addTxOperationOnComplete(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ promise.completeWith(op.invoke(transactionContext));
+ }
+ });
+
+ future = promise.future();
+ }
+
+ return future;
+ }
+
+ <T> CheckedFuture<T, ReadFailedException> enqueueReadOperation(final ReadOperation<T> op) {
+
+ CheckedFuture<T, ReadFailedException> future;
+
+ if (transactionContext != null) {
+ future = op.invoke(transactionContext);
+ } else {
+ // The shard Tx hasn't been created yet so add the Tx operation to the Tx Future
+ // callback to be executed after the Tx is created.
+ final SettableFuture<T> proxyFuture = SettableFuture.create();
+ addTxOperationOnComplete(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ Futures.addCallback(op.invoke(transactionContext), new FutureCallback<T>() {
+ @Override
+ public void onSuccess(T data) {
+ proxyFuture.set(data);
+ }
+
+ @Override
+ public void onFailure(Throwable t) {
+ proxyFuture.setException(t);
+ }
+ });
+ }
+ });
+
+ future = MappingCheckedFuture.create(proxyFuture, ReadFailedException.MAPPER);
+ }
+
+ return future;
+ }
- ActorSelection actorSelection =
- remoteTransactionPaths.get(shardName);
+ void enqueueModifyOperation(final TransactionOperation op) {
- if(actorSelection != null){
- // A transaction already exists with that shard
- return;
+ if (transactionContext != null) {
+ op.invoke(transactionContext);
+ } else {
+ // The shard Tx hasn't been created yet so add the Tx operation to the Tx Future
+ // callback to be executed after the Tx is created.
+ addTxOperationOnComplete(op);
+ }
}
- Object response = actorContext.executeShardOperation(shardName, new CreateTransaction(identifier), ActorContext.ASK_DURATION);
- if(response instanceof CreateTransactionReply){
- CreateTransactionReply reply = (CreateTransactionReply) response;
- remoteTransactionPaths.put(shardName, actorContext.actorSelection(reply.getTransactionActorPath()));
+
+
+
+
+ /**
+ * Performs a CreateTransaction try async.
+ */
+ private void tryCreateTransaction() {
+ Future<Object> createTxFuture = sendCreateTransaction(primaryShard,
+ new CreateTransaction(identifier.toString(),
+ TransactionProxy.this.transactionType.ordinal(),
+ getTransactionChainId()).toSerializable());
+
+ createTxFuture.onComplete(this, actorContext.getActorSystem().dispatcher());
+ }
+
+ @Override
+ public void onComplete(Throwable failure, Object response) {
+ if(failure instanceof NoShardLeaderException) {
+ // There's no leader for the shard yet - schedule and try again, unless we're out
+ // of retries. Note: createTxTries is volatile as it may be written by different
+ // threads however not concurrently, therefore decrementing it non-atomically here
+ // is ok.
+ if(--createTxTries > 0) {
+ LOG.debug("Tx {} Shard {} has no leader yet - scheduling create Tx retry",
+ identifier, shardName);
+
+ actorContext.getActorSystem().scheduler().scheduleOnce(CREATE_TX_TRY_INTERVAL,
+ new Runnable() {
+ @Override
+ public void run() {
+ tryCreateTransaction();
+ }
+ }, actorContext.getActorSystem().dispatcher());
+ return;
+ }
+ }
+
+ // Create the TransactionContext from the response or failure and execute delayed
+ // TransactionOperations. This entire section is done atomically (ie synchronized) with
+ // respect to #addTxOperationOnComplete to handle timing issues and ensure no
+ // TransactionOperation is missed and that they are processed in the order they occurred.
+ synchronized(txOperationsOnComplete) {
+ // Store the new TransactionContext locally until we've completed invoking the
+ // TransactionOperations. This avoids thread timing issues which could cause
+ // out-of-order TransactionOperations. Eg, on a modification operation, if the
+ // TransactionContext is non-null, then we directly call the TransactionContext.
+ // However, at the same time, the code may be executing the cached
+ // TransactionOperations. So to avoid thus timing, we don't publish the
+ // TransactionContext until after we've executed all cached TransactionOperations.
+ TransactionContext localTransactionContext;
+ if(failure != null) {
+ LOG.debug("Tx {} Creating NoOpTransaction because of error: {}", identifier,
+ failure.getMessage());
+
+ localTransactionContext = new NoOpTransactionContext(failure, identifier);
+ } else if (response.getClass().equals(CreateTransactionReply.SERIALIZABLE_CLASS)) {
+ localTransactionContext = createValidTransactionContext(
+ CreateTransactionReply.fromSerializable(response));
+ } else {
+ IllegalArgumentException exception = new IllegalArgumentException(String.format(
+ "Invalid reply type %s for CreateTransaction", response.getClass()));
+
+ localTransactionContext = new NoOpTransactionContext(exception, identifier);
+ }
+
+ for(TransactionOperation oper: txOperationsOnComplete) {
+ oper.invoke(localTransactionContext);
+ }
+
+ txOperationsOnComplete.clear();
+
+ // We're done invoking the TransactionOperations so we can now publish the
+ // TransactionContext.
+ transactionContext = localTransactionContext;
+ }
+ }
+
+ private TransactionContext createValidTransactionContext(CreateTransactionReply reply) {
+ String transactionPath = reply.getTransactionPath();
+
+ LOG.debug("Tx {} Received transaction actor path {}", identifier, transactionPath);
+
+ ActorSelection transactionActor = actorContext.actorSelection(transactionPath);
+
+ if (transactionType == TransactionType.READ_ONLY) {
+ // Add the actor to the remoteTransactionActors list for access by the
+ // cleanup PhantonReference.
+ remoteTransactionActors.add(transactionActor);
+
+ // Write to the memory barrier volatile to publish the above update to the
+ // remoteTransactionActors list for thread visibility.
+ remoteTransactionActorsMB.set(true);
+ }
+
+ // TxActor is always created where the leader of the shard is.
+ // Check if TxActor is created in the same node
+ boolean isTxActorLocal = actorContext.isPathLocal(transactionPath);
+
+ return new TransactionContextImpl(transactionPath, transactionActor, identifier,
+ actorContext, schemaContext, isTxActorLocal, reply.getVersion());
+ }
+ }
+
+ private interface TransactionContext {
+ void closeTransaction();
+
+ Future<ActorSelection> readyTransaction();
+
+ void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data);
+
+ void deleteData(YangInstanceIdentifier path);
+
+ void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data);
+
+ CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> readData(
+ final YangInstanceIdentifier path);
+
+ CheckedFuture<Boolean, ReadFailedException> dataExists(YangInstanceIdentifier path);
+
+ List<Future<Object>> getRecordedOperationFutures();
+ }
+
+ private static abstract class AbstractTransactionContext implements TransactionContext {
+
+ protected final TransactionIdentifier identifier;
+ protected final List<Future<Object>> recordedOperationFutures = Lists.newArrayList();
+
+ AbstractTransactionContext(TransactionIdentifier identifier) {
+ this.identifier = identifier;
+ }
+
+ @Override
+ public List<Future<Object>> getRecordedOperationFutures() {
+ return recordedOperationFutures;
}
}
+ private static class TransactionContextImpl extends AbstractTransactionContext {
+ private final Logger LOG = LoggerFactory.getLogger(TransactionContextImpl.class);
+
+ private final ActorContext actorContext;
+ private final SchemaContext schemaContext;
+ private final String transactionPath;
+ private final ActorSelection actor;
+ private final boolean isTxActorLocal;
+ private final int remoteTransactionVersion;
+
+ private TransactionContextImpl(String transactionPath, ActorSelection actor, TransactionIdentifier identifier,
+ ActorContext actorContext, SchemaContext schemaContext,
+ boolean isTxActorLocal, int remoteTransactionVersion) {
+ super(identifier);
+ this.transactionPath = transactionPath;
+ this.actor = actor;
+ this.actorContext = actorContext;
+ this.schemaContext = schemaContext;
+ this.isTxActorLocal = isTxActorLocal;
+ this.remoteTransactionVersion = remoteTransactionVersion;
+ }
+
+ private ActorSelection getActor() {
+ return actor;
+ }
+
+ private Future<Object> executeOperationAsync(SerializableMessage msg) {
+ return actorContext.executeOperationAsync(getActor(), isTxActorLocal ? msg : msg.toSerializable());
+ }
+
+ @Override
+ public void closeTransaction() {
+ LOG.debug("Tx {} closeTransaction called", identifier);
+
+ actorContext.sendOperationAsync(getActor(), new CloseTransaction().toSerializable());
+ }
+
+ @Override
+ public Future<ActorSelection> readyTransaction() {
+ LOG.debug("Tx {} readyTransaction called with {} previous recorded operations pending",
+ identifier, recordedOperationFutures.size());
+
+ // Send the ReadyTransaction message to the Tx actor.
+
+ final Future<Object> replyFuture = executeOperationAsync(new ReadyTransaction());
+
+ // Combine all the previously recorded put/merge/delete operation reply Futures and the
+ // ReadyTransactionReply Future into one Future. If any one fails then the combined
+ // Future will fail. We need all prior operations and the ready operation to succeed
+ // in order to attempt commit.
+
+ List<Future<Object>> futureList =
+ Lists.newArrayListWithCapacity(recordedOperationFutures.size() + 1);
+ futureList.addAll(recordedOperationFutures);
+ futureList.add(replyFuture);
+
+ Future<Iterable<Object>> combinedFutures = akka.dispatch.Futures.sequence(futureList,
+ actorContext.getActorSystem().dispatcher());
+
+ // Transform the combined Future into a Future that returns the cohort actor path from
+ // the ReadyTransactionReply. That's the end result of the ready operation.
+
+ return combinedFutures.transform(new Mapper<Iterable<Object>, ActorSelection>() {
+ @Override
+ public ActorSelection checkedApply(Iterable<Object> notUsed) {
+ LOG.debug("Tx {} readyTransaction: pending recorded operations succeeded",
+ identifier);
+
+ // At this point all the Futures succeeded and we need to extract the cohort
+ // actor path from the ReadyTransactionReply. For the recorded operations, they
+ // don't return any data so we're only interested that they completed
+ // successfully. We could be paranoid and verify the correct reply types but
+ // that really should never happen so it's not worth the overhead of
+ // de-serializing each reply.
+
+ // Note the Future get call here won't block as it's complete.
+ Object serializedReadyReply = replyFuture.value().get().get();
+ if (serializedReadyReply instanceof ReadyTransactionReply) {
+ return actorContext.actorSelection(((ReadyTransactionReply)serializedReadyReply).getCohortPath());
+
+ } else if(serializedReadyReply.getClass().equals(ReadyTransactionReply.SERIALIZABLE_CLASS)) {
+ ReadyTransactionReply reply = ReadyTransactionReply.fromSerializable(serializedReadyReply);
+ String cohortPath = reply.getCohortPath();
+
+ // In Helium we used to return the local path of the actor which represented
+ // a remote ThreePhaseCommitCohort. The local path would then be converted to
+ // a remote path using this resolvePath method. To maintain compatibility with
+ // a Helium node we need to continue to do this conversion.
+ // At some point in the future when upgrades from Helium are not supported
+ // we could remove this code to resolvePath and just use the cohortPath as the
+ // resolved cohortPath
+ if(TransactionContextImpl.this.remoteTransactionVersion < CreateTransaction.HELIUM_1_VERSION) {
+ cohortPath = actorContext.resolvePath(transactionPath, cohortPath);
+ }
+
+ return actorContext.actorSelection(cohortPath);
+
+ } else {
+ // Throwing an exception here will fail the Future.
+ throw new IllegalArgumentException(String.format("Invalid reply type {}",
+ serializedReadyReply.getClass()));
+ }
+ }
+ }, SAME_FAILURE_TRANSFORMER, actorContext.getActorSystem().dispatcher());
+ }
+
+ @Override
+ public void deleteData(YangInstanceIdentifier path) {
+ LOG.debug("Tx {} deleteData called path = {}", identifier, path);
+
+ recordedOperationFutures.add(executeOperationAsync(new DeleteData(path)));
+ }
+
+ @Override
+ public void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} mergeData called path = {}", identifier, path);
+
+ recordedOperationFutures.add(executeOperationAsync(new MergeData(path, data, schemaContext)));
+ }
+ @Override
+ public void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} writeData called path = {}", identifier, path);
+
+ recordedOperationFutures.add(executeOperationAsync(new WriteData(path, data, schemaContext)));
+ }
+
+ @Override
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> readData(
+ final YangInstanceIdentifier path) {
+
+ LOG.debug("Tx {} readData called path = {}", identifier, path);
+
+ final SettableFuture<Optional<NormalizedNode<?, ?>>> returnFuture = SettableFuture.create();
+
+ // If there were any previous recorded put/merge/delete operation reply Futures then we
+ // must wait for them to successfully complete. This is necessary to honor the read
+ // uncommitted semantics of the public API contract. If any one fails then fail the read.
+
+ if(recordedOperationFutures.isEmpty()) {
+ finishReadData(path, returnFuture);
+ } else {
+ LOG.debug("Tx {} readData: verifying {} previous recorded operations",
+ identifier, recordedOperationFutures.size());
+
+ // Note: we make a copy of recordedOperationFutures to be on the safe side in case
+ // Futures#sequence accesses the passed List on a different thread, as
+ // recordedOperationFutures is not synchronized.
+
+ Future<Iterable<Object>> combinedFutures = akka.dispatch.Futures.sequence(
+ Lists.newArrayList(recordedOperationFutures),
+ actorContext.getActorSystem().dispatcher());
+
+ OnComplete<Iterable<Object>> onComplete = new OnComplete<Iterable<Object>>() {
+ @Override
+ public void onComplete(Throwable failure, Iterable<Object> notUsed)
+ throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} readData: a recorded operation failed: {}",
+ identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "The read could not be performed because a previous put, merge,"
+ + "or delete operation failed", failure));
+ } else {
+ finishReadData(path, returnFuture);
+ }
+ }
+ };
+
+ combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+
+ return MappingCheckedFuture.create(returnFuture, ReadFailedException.MAPPER);
+ }
+
+ private void finishReadData(final YangInstanceIdentifier path,
+ final SettableFuture<Optional<NormalizedNode<?, ?>>> returnFuture) {
+
+ LOG.debug("Tx {} finishReadData called path = {}", identifier, path);
+
+ OnComplete<Object> onComplete = new OnComplete<Object>() {
+ @Override
+ public void onComplete(Throwable failure, Object readResponse) throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} read operation failed: {}", identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "Error reading data for path " + path, failure));
+
+ } else {
+ LOG.debug("Tx {} read operation succeeded", identifier, failure);
+
+ if (readResponse instanceof ReadDataReply) {
+ ReadDataReply reply = (ReadDataReply) readResponse;
+ returnFuture.set(Optional.<NormalizedNode<?, ?>>fromNullable(reply.getNormalizedNode()));
+
+ } else if (readResponse.getClass().equals(ReadDataReply.SERIALIZABLE_CLASS)) {
+ ReadDataReply reply = ReadDataReply.fromSerializable(schemaContext, path, readResponse);
+ returnFuture.set(Optional.<NormalizedNode<?, ?>>fromNullable(reply.getNormalizedNode()));
+
+ } else {
+ returnFuture.setException(new ReadFailedException(
+ "Invalid response reading data for path " + path));
+ }
+ }
+ }
+ };
+
+ Future<Object> readFuture = executeOperationAsync(new ReadData(path));
+
+ readFuture.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> dataExists(
+ final YangInstanceIdentifier path) {
+
+ LOG.debug("Tx {} dataExists called path = {}", identifier, path);
+
+ final SettableFuture<Boolean> returnFuture = SettableFuture.create();
+
+ // If there were any previous recorded put/merge/delete operation reply Futures then we
+ // must wait for them to successfully complete. This is necessary to honor the read
+ // uncommitted semantics of the public API contract. If any one fails then fail this
+ // request.
+
+ if(recordedOperationFutures.isEmpty()) {
+ finishDataExists(path, returnFuture);
+ } else {
+ LOG.debug("Tx {} dataExists: verifying {} previous recorded operations",
+ identifier, recordedOperationFutures.size());
+
+ // Note: we make a copy of recordedOperationFutures to be on the safe side in case
+ // Futures#sequence accesses the passed List on a different thread, as
+ // recordedOperationFutures is not synchronized.
+
+ Future<Iterable<Object>> combinedFutures = akka.dispatch.Futures.sequence(
+ Lists.newArrayList(recordedOperationFutures),
+ actorContext.getActorSystem().dispatcher());
+ OnComplete<Iterable<Object>> onComplete = new OnComplete<Iterable<Object>>() {
+ @Override
+ public void onComplete(Throwable failure, Iterable<Object> notUsed)
+ throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} dataExists: a recorded operation failed: {}",
+ identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "The data exists could not be performed because a previous "
+ + "put, merge, or delete operation failed", failure));
+ } else {
+ finishDataExists(path, returnFuture);
+ }
+ }
+ };
+
+ combinedFutures.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+
+ return MappingCheckedFuture.create(returnFuture, ReadFailedException.MAPPER);
+ }
+
+ private void finishDataExists(final YangInstanceIdentifier path,
+ final SettableFuture<Boolean> returnFuture) {
+
+ LOG.debug("Tx {} finishDataExists called path = {}", identifier, path);
+
+ OnComplete<Object> onComplete = new OnComplete<Object>() {
+ @Override
+ public void onComplete(Throwable failure, Object response) throws Throwable {
+ if(failure != null) {
+ LOG.debug("Tx {} dataExists operation failed: {}", identifier, failure);
+ returnFuture.setException(new ReadFailedException(
+ "Error checking data exists for path " + path, failure));
+ } else {
+ LOG.debug("Tx {} dataExists operation succeeded", identifier, failure);
+
+ if (response instanceof DataExistsReply) {
+ returnFuture.set(Boolean.valueOf(((DataExistsReply) response).exists()));
+
+ } else if (response.getClass().equals(DataExistsReply.SERIALIZABLE_CLASS)) {
+ returnFuture.set(Boolean.valueOf(DataExistsReply.fromSerializable(response).exists()));
+
+ } else {
+ returnFuture.setException(new ReadFailedException(
+ "Invalid response checking exists for path " + path));
+ }
+ }
+ }
+ };
+
+ Future<Object> future = executeOperationAsync(new DataExists(path));
+
+ future.onComplete(onComplete, actorContext.getActorSystem().dispatcher());
+ }
+ }
+
+ private static class NoOpTransactionContext extends AbstractTransactionContext {
+
+ private final Logger LOG = LoggerFactory.getLogger(NoOpTransactionContext.class);
+
+ private final Throwable failure;
+
+ public NoOpTransactionContext(Throwable failure, TransactionIdentifier identifier){
+ super(identifier);
+ this.failure = failure;
+ }
+
+ @Override
+ public void closeTransaction() {
+ LOG.debug("NoOpTransactionContext {} closeTransaction called", identifier);
+ }
+
+ @Override
+ public Future<ActorSelection> readyTransaction() {
+ LOG.debug("Tx {} readyTransaction called", identifier);
+ return akka.dispatch.Futures.failed(failure);
+ }
+
+ @Override
+ public void deleteData(YangInstanceIdentifier path) {
+ LOG.debug("Tx {} deleteData called path = {}", identifier, path);
+ }
+
+ @Override
+ public void mergeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} mergeData called path = {}", identifier, path);
+ }
+
+ @Override
+ public void writeData(YangInstanceIdentifier path, NormalizedNode<?, ?> data) {
+ LOG.debug("Tx {} writeData called path = {}", identifier, path);
+ }
+
+ @Override
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> readData(
+ YangInstanceIdentifier path) {
+ LOG.debug("Tx {} readData called path = {}", identifier, path);
+ return Futures.immediateFailedCheckedFuture(new ReadFailedException(
+ "Error reading data for path " + path, failure));
+ }
+
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> dataExists(
+ YangInstanceIdentifier path) {
+ LOG.debug("Tx {} dataExists called path = {}", identifier, path);
+ return Futures.immediateFailedCheckedFuture(new ReadFailedException(
+ "Error checking exists for path " + path, failure));
+ }
+ }
}