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.base.Preconditions;
+import com.google.common.collect.Lists;
+import com.google.common.util.concurrent.CheckedFuture;
import com.google.common.util.concurrent.ListenableFuture;
-import com.google.common.util.concurrent.ListenableFutureTask;
+import com.google.common.util.concurrent.SettableFuture;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Semaphore;
+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.compat.PreLithiumTransactionContextImpl;
+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.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.WriteData;
+import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
+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
+ READ_WRITE;
+
+ public static TransactionType fromInt(int type) {
+ if(type == WRITE_ONLY.ordinal()) {
+ return WRITE_ONLY;
+ } else if(type == READ_WRITE.ordinal()) {
+ return READ_WRITE;
+ } else if(type == READ_ONLY.ordinal()) {
+ return READ_ONLY;
+ } else {
+ throw new IllegalArgumentException("In TransactionType enum value" + type);
+ }
+ }
}
+ 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, CloseTransaction.INSTANCE.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 volatile 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;
+
+ private volatile boolean initialized;
+ private Semaphore operationLimiter;
+ private OperationCompleter operationCompleter;
+
+ public TransactionProxy(ActorContext actorContext, TransactionType transactionType) {
+ this(actorContext, transactionType, "");
+ }
- public TransactionProxy(
- ActorContext actorContext,
- TransactionType transactionType,
- ExecutorService executor,
- SchemaContext schemaContext
- ) {
+ 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;
- this.identifier = "txn-" + counter.getAndIncrement();
- this.transactionType = transactionType;
- this.actorContext = actorContext;
- this.executor = executor;
- this.schemaContext = schemaContext;
+ String memberName = actorContext.getCurrentMemberName();
+ if(memberName == null){
+ memberName = "UNKNOWN-MEMBER";
+ }
+
+ this.identifier = new TransactionIdentifier(memberName, counter.getAndIncrement());
+
+ LOG.debug("Created txn {} of type {} on chain {}", identifier, transactionType, transactionChainId);
+ }
- Object response = actorContext.executeShardOperation(Shard.DEFAULT_NAME, new CreateTransaction(identifier), ActorContext.ASK_DURATION);
- if(response instanceof CreateTransactionReply){
- CreateTransactionReply reply = (CreateTransactionReply) response;
- remoteTransactionPaths.put(Shard.DEFAULT_NAME, actorContext.actorSelection(reply.getTransactionActorPath()));
+ @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;
+ }
+ }
+
+ return false;
}
@Override
- public ListenableFuture<Optional<NormalizedNode<?, ?>>> read(final InstanceIdentifier path) {
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
-
- Callable<Optional<NormalizedNode<?,?>>> call = new Callable() {
-
- @Override public Optional<NormalizedNode<?,?>> call() throws Exception {
- Object response = actorContext
- .executeRemoteOperation(remoteTransaction, new ReadData(path),
- ActorContext.ASK_DURATION);
- if(response instanceof ReadDataReply){
- ReadDataReply reply = (ReadDataReply) response;
- if(reply.getNormalizedNode() == null){
- return Optional.absent();
- }
- //FIXME : A cast should not be required here ???
- return (Optional<NormalizedNode<?, ?>>) Optional.of(reply.getNormalizedNode());
- }
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
- return Optional.absent();
+ Preconditions.checkState(transactionType != TransactionType.WRITE_ONLY,
+ "Read operation on write-only transaction is not allowed");
+
+ LOG.debug("Tx {} read {}", identifier, path);
+
+ throttleOperation();
+
+ final SettableFuture<Optional<NormalizedNode<?, ?>>> proxyFuture = SettableFuture.create();
+
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.readData(path, proxyFuture);
}
- };
+ });
+
+ return MappingCheckedFuture.create(proxyFuture, ReadFailedException.MAPPER);
+ }
+
+ @Override
+ public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
+
+ Preconditions.checkState(transactionType != TransactionType.WRITE_ONLY,
+ "Exists operation on write-only transaction is not allowed");
+
+ LOG.debug("Tx {} exists {}", identifier, path);
+
+ throttleOperation();
- ListenableFutureTask<Optional<NormalizedNode<?, ?>>>
- future = ListenableFutureTask.create(call);
+ final SettableFuture<Boolean> proxyFuture = SettableFuture.create();
- executor.submit(future);
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.dataExists(path, proxyFuture);
+ }
+ });
+
+ return MappingCheckedFuture.create(proxyFuture, ReadFailedException.MAPPER);
+ }
- return future;
+ 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");
}
+ private void throttleOperation() {
+ throttleOperation(1);
+ }
+
+ private void throttleOperation(int acquirePermits) {
+ if(!initialized) {
+ // Note : Currently mailbox-capacity comes from akka.conf and not from the config-subsystem
+ operationLimiter = new Semaphore(actorContext.getTransactionOutstandingOperationLimit());
+ operationCompleter = new OperationCompleter(operationLimiter);
+
+ // Make sure we write this last because it's volatile and will also publish the non-volatile writes
+ // above as well so they'll be visible to other threads.
+ initialized = true;
+ }
+
+ try {
+ if(!operationLimiter.tryAcquire(acquirePermits,
+ actorContext.getDatastoreContext().getOperationTimeoutInSeconds(), TimeUnit.SECONDS)){
+ LOG.warn("Failed to acquire operation permit for transaction {}", getIdentifier());
+ }
+ } catch (InterruptedException e) {
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("Interrupted when trying to acquire operation permit for transaction " + getIdentifier().toString(), e);
+ } else {
+ LOG.warn("Interrupted when trying to acquire operation permit for transaction {}", getIdentifier());
+ }
+ }
+ }
+
+
@Override
- public void write(InstanceIdentifier path, NormalizedNode<?, ?> data) {
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
- remoteTransaction.tell(new WriteData(path, data, schemaContext).toSerializable(), null);
+ public void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
+
+ checkModificationState();
+
+ LOG.debug("Tx {} write {}", identifier, path);
+
+ throttleOperation();
+
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.writeData(path, data);
+ }
+ });
}
@Override
- public void merge(InstanceIdentifier path, NormalizedNode<?, ?> data) {
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
- remoteTransaction.tell(new MergeData(path, data, schemaContext).toSerializable(), null);
+ public void merge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
+
+ checkModificationState();
+
+ LOG.debug("Tx {} merge {}", identifier, path);
+
+ throttleOperation();
+
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.mergeData(path, data);
+ }
+ });
}
@Override
- public void delete(InstanceIdentifier path) {
- final ActorSelection remoteTransaction = remoteTransactionFromIdentifier(path);
- remoteTransaction.tell(new DeleteData(path).toSerializable(), null);
+ public void delete(final YangInstanceIdentifier path) {
+
+ checkModificationState();
+
+ LOG.debug("Tx {} delete {}", identifier, path);
+
+ throttleOperation();
+
+ TransactionFutureCallback txFutureCallback = getOrCreateTxFutureCallback(path);
+ txFutureCallback.enqueueTransactionOperation(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());
+
+ if(txFutureCallbackMap.size() == 0) {
+ onTransactionReady(Collections.<Future<ActorSelection>>emptyList());
+ TransactionRateLimitingCallback.adjustRateLimitForUnusedTransaction(actorContext);
+ return NoOpDOMStoreThreePhaseCommitCohort.INSTANCE;
+ }
+
+ throttleOperation(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);
+
+ final TransactionContext transactionContext = txFutureCallback.getTransactionContext();
+ final Future<ActorSelection> future;
+ if (transactionContext != null) {
+ // avoid the creation of a promise and a TransactionOperation
+ future = transactionContext.readyTransaction();
+ } else {
+ final Promise<ActorSelection> promise = akka.dispatch.Futures.promise();
+ txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ promise.completeWith(transactionContext.readyTransaction());
+ }
+ });
+ future = promise.future();
}
+
+ 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) {
}
@Override
@Override
public void close() {
- for(ActorSelection remoteTransaction : remoteTransactionPaths.values()) {
- remoteTransaction.tell(new CloseTransaction(), null);
+ for (TransactionFutureCallback txFutureCallback : txFutureCallbackMap.values()) {
+ txFutureCallback.enqueueTransactionOperation(new TransactionOperation() {
+ @Override
+ public void invoke(TransactionContext transactionContext) {
+ transactionContext.closeTransaction();
+ }
+ });
+ }
+
+ txFutureCallbackMap.clear();
+
+ if(remoteTransactionActorsMB != null) {
+ remoteTransactionActors.clear();
+ remoteTransactionActorsMB.set(true);
}
}
- private ActorSelection remoteTransactionFromIdentifier(InstanceIdentifier path){
+ private String shardNameFromIdentifier(YangInstanceIdentifier path){
+ return ShardStrategyFactory.getStrategy(path).findShard(path);
+ }
+
+ protected Future<ActorSelection> sendFindPrimaryShardAsync(String shardName) {
+ return actorContext.findPrimaryShardAsync(shardName);
+ }
+
+ private TransactionFutureCallback getOrCreateTxFutureCallback(YangInstanceIdentifier path) {
String shardName = shardNameFromIdentifier(path);
- return remoteTransactionPaths.get(shardName);
+ TransactionFutureCallback txFutureCallback = txFutureCallbackMap.get(shardName);
+ if(txFutureCallback == null) {
+ Future<ActorSelection> findPrimaryFuture = sendFindPrimaryShardAsync(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.createTransactionContext(failure, null);
+ } else {
+ newTxFutureCallback.setPrimaryShard(primaryShard);
+ }
+ }
+ }, actorContext.getClientDispatcher());
+ }
+
+ return txFutureCallback;
+ }
+
+ 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);
}
- private String shardNameFromIdentifier(InstanceIdentifier path){
- return Shard.DEFAULT_NAME;
+ /**
+ * 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) {
+ this.primaryShard = primaryShard;
+
+ if(transactionType == TransactionType.WRITE_ONLY &&
+ actorContext.getDatastoreContext().isWriteOnlyTransactionOptimizationsEnabled()) {
+ LOG.debug("Tx {} Primary shard {} found - creating WRITE_ONLY transaction context",
+ identifier, primaryShard);
+
+ // For write-only Tx's we prepare the transaction modifications directly on the shard actor
+ // to avoid the overhead of creating a separate transaction actor.
+ // FIXME: can't assume the shard version is LITHIUM_VERSION - need to obtain it somehow.
+ executeTxOperatonsOnComplete(createValidTransactionContext(this.primaryShard,
+ this.primaryShard.path().toString(), DataStoreVersions.LITHIUM_VERSION));
+ } else {
+ tryCreateTransaction();
+ }
+ }
+
+ /**
+ * Adds a TransactionOperation to be executed after the CreateTransaction completes.
+ */
+ void addTxOperationOnComplete(TransactionOperation operation) {
+ boolean invokeOperation = true;
+ synchronized(txOperationsOnComplete) {
+ if(transactionContext == null) {
+ LOG.debug("Tx {} Adding operation on complete", identifier);
+
+ invokeOperation = false;
+ txOperationsOnComplete.add(operation);
+ }
+ }
+
+ if(invokeOperation) {
+ operation.invoke(transactionContext);
+ }
+ }
+
+ void enqueueTransactionOperation(final TransactionOperation op) {
+
+ 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);
+ }
+ }
+
+ /**
+ * Performs a CreateTransaction try async.
+ */
+ private void tryCreateTransaction() {
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("Tx {} Primary shard {} found - trying create transaction", identifier, primaryShard);
+ }
+
+ Object serializedCreateMessage = new CreateTransaction(identifier.toString(),
+ TransactionProxy.this.transactionType.ordinal(),
+ getTransactionChainId()).toSerializable();
+
+ Future<Object> createTxFuture = actorContext.executeOperationAsync(primaryShard, serializedCreateMessage);
+
+ createTxFuture.onComplete(this, actorContext.getClientDispatcher());
+ }
+
+ @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.getClientDispatcher());
+ return;
+ }
+ }
+
+ createTransactionContext(failure, response);
+ }
+
+ private void createTransactionContext(Throwable failure, Object response) {
+ // Mainly checking for state violation here to perform a volatile read of "initialized" to
+ // ensure updates to operationLimter et al are visible to this thread (ie we're doing
+ // "piggy-back" synchronization here).
+ Preconditions.checkState(initialized, "Tx was not propertly initialized.");
+
+ // Create the TransactionContext from the response or failure. 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);
+
+ localTransactionContext = new NoOpTransactionContext(failure, identifier, operationLimiter);
+ } 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, operationLimiter);
+ }
+
+ executeTxOperatonsOnComplete(localTransactionContext);
+ }
+
+ private void executeTxOperatonsOnComplete(TransactionContext localTransactionContext) {
+ while(true) {
+ // Access to txOperationsOnComplete and transactionContext must be protected and atomic
+ // (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.
+
+ // We'll make a local copy of the txOperationsOnComplete list to handle re-entrancy
+ // in case a TransactionOperation results in another transaction operation being
+ // queued (eg a put operation from a client read Future callback that is notified
+ // synchronously).
+ Collection<TransactionOperation> operationsBatch = null;
+ synchronized(txOperationsOnComplete) {
+ if(txOperationsOnComplete.isEmpty()) {
+ // We're done invoking the TransactionOperations so we can now publish the
+ // TransactionContext.
+ transactionContext = localTransactionContext;
+ break;
+ }
+
+ operationsBatch = new ArrayList<>(txOperationsOnComplete);
+ txOperationsOnComplete.clear();
+ }
+
+ // Invoke TransactionOperations outside the sync block to avoid unnecessary blocking.
+ // A slight down-side is that we need to re-acquire the lock below but this should
+ // be negligible.
+ for(TransactionOperation oper: operationsBatch) {
+ oper.invoke(localTransactionContext);
+ }
+ }
+ }
+
+ private TransactionContext createValidTransactionContext(CreateTransactionReply reply) {
+ LOG.debug("Tx {} Received {}", identifier, reply);
+
+ return createValidTransactionContext(actorContext.actorSelection(reply.getTransactionPath()),
+ reply.getTransactionPath(), reply.getVersion());
+ }
+
+ private TransactionContext createValidTransactionContext(ActorSelection transactionActor,
+ String transactionPath, short remoteTransactionVersion) {
+
+ 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.
+
+ if(remoteTransactionActorsMB == null) {
+ remoteTransactionActors = Lists.newArrayList();
+ remoteTransactionActorsMB = new AtomicBoolean();
+
+ TransactionProxyCleanupPhantomReference cleanup =
+ new TransactionProxyCleanupPhantomReference(TransactionProxy.this);
+ phantomReferenceCache.put(cleanup, cleanup);
+ }
+
+ // 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);
+
+ if(remoteTransactionVersion < DataStoreVersions.LITHIUM_VERSION) {
+ return new PreLithiumTransactionContextImpl(transactionPath, transactionActor, identifier,
+ transactionChainId, actorContext, schemaContext, isTxActorLocal, remoteTransactionVersion,
+ operationCompleter);
+ } else if (transactionType == TransactionType.WRITE_ONLY &&
+ actorContext.getDatastoreContext().isWriteOnlyTransactionOptimizationsEnabled()) {
+ return new WriteOnlyTransactionContextImpl(transactionActor, identifier, transactionChainId,
+ actorContext, schemaContext, isTxActorLocal, remoteTransactionVersion, operationCompleter);
+ } else {
+ return new TransactionContextImpl(transactionActor, identifier, transactionChainId,
+ actorContext, schemaContext, isTxActorLocal, remoteTransactionVersion, operationCompleter);
+ }
+ }
+ }
+
+ private static class NoOpDOMStoreThreePhaseCommitCohort implements DOMStoreThreePhaseCommitCohort {
+ static NoOpDOMStoreThreePhaseCommitCohort INSTANCE = new NoOpDOMStoreThreePhaseCommitCohort();
+
+ private static final ListenableFuture<Void> IMMEDIATE_VOID_SUCCESS =
+ com.google.common.util.concurrent.Futures.immediateFuture(null);
+ private static final ListenableFuture<Boolean> IMMEDIATE_BOOLEAN_SUCCESS =
+ com.google.common.util.concurrent.Futures.immediateFuture(Boolean.TRUE);
+
+ private NoOpDOMStoreThreePhaseCommitCohort() {
+ }
+
+ @Override
+ public ListenableFuture<Boolean> canCommit() {
+ return IMMEDIATE_BOOLEAN_SUCCESS;
+ }
+
+ @Override
+ public ListenableFuture<Void> preCommit() {
+ return IMMEDIATE_VOID_SUCCESS;
+ }
+
+ @Override
+ public ListenableFuture<Void> abort() {
+ return IMMEDIATE_VOID_SUCCESS;
+ }
+
+ @Override
+ public ListenableFuture<Void> commit() {
+ return IMMEDIATE_VOID_SUCCESS;
+ }
}
}
Code Review / controller.git / blobdiff