+++ /dev/null
-/*
- * Copyright (c) 2015 Brocade Communications Systems, Inc. and others. All rights reserved.
- * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Public License v1.0 which accompanies this distribution,
- * and is available at http://www.eclipse.org/legal/epl-v10.html
- */
-package org.opendaylight.controller.cluster.datastore;
-
-import akka.actor.ActorSelection;
-import akka.dispatch.OnComplete;
-import akka.pattern.AskTimeoutException;
-import akka.util.Timeout;
-import com.google.common.base.Preconditions;
-import java.util.concurrent.TimeUnit;
-import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
-import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
-import org.opendaylight.controller.cluster.datastore.exceptions.ShardLeaderNotRespondingException;
-import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
-import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
-import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo;
-import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-import scala.concurrent.Future;
-import scala.concurrent.duration.FiniteDuration;
-
-/**
- * Handles creation of TransactionContext instances for remote transactions. This class creates
- * remote transactions, if necessary, by sending CreateTransaction messages with 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 via a TransactionContextWrapper and executed once the
- * CreateTransaction completes, successfully or not.
- */
-final class RemoteTransactionContextSupport {
- private static final Logger LOG = LoggerFactory.getLogger(RemoteTransactionContextSupport.class);
-
- private static final long CREATE_TX_TRY_INTERVAL_IN_MS = 1000;
- private static final long MAX_CREATE_TX_MSG_TIMEOUT_IN_MS = 5000;
-
- private final TransactionProxy parent;
- private final String shardName;
-
- /**
- * The target primary shard.
- */
- private volatile PrimaryShardInfo primaryShardInfo;
-
- /**
- * The total timeout for creating a tx on the primary shard.
- */
- private volatile long totalCreateTxTimeout;
-
- private final Timeout createTxMessageTimeout;
-
- private final TransactionContextWrapper transactionContextWrapper;
-
- RemoteTransactionContextSupport(final TransactionContextWrapper transactionContextWrapper,
- final TransactionProxy parent, final String shardName) {
- this.parent = Preconditions.checkNotNull(parent);
- this.shardName = shardName;
- this.transactionContextWrapper = transactionContextWrapper;
-
- // For the total create tx timeout, use 2 times the election timeout. This should be enough time for
- // a leader re-election to occur if we happen to hit it in transition.
- totalCreateTxTimeout = parent.getActorContext().getDatastoreContext().getShardRaftConfig()
- .getElectionTimeOutInterval().toMillis() * 2;
-
- // We'll use the operationTimeout for the the create Tx message timeout so it can be set appropriately
- // for unit tests but cap it at MAX_CREATE_TX_MSG_TIMEOUT_IN_MS. The operationTimeout could be set
- // larger than the totalCreateTxTimeout in production which we don't want.
- long operationTimeout = parent.getActorContext().getOperationTimeout().duration().toMillis();
- createTxMessageTimeout = new Timeout(Math.min(operationTimeout, MAX_CREATE_TX_MSG_TIMEOUT_IN_MS),
- TimeUnit.MILLISECONDS);
- }
-
- String getShardName() {
- return shardName;
- }
-
- private TransactionType getTransactionType() {
- return parent.getType();
- }
-
- private ActorContext getActorContext() {
- return parent.getActorContext();
- }
-
- private TransactionIdentifier getIdentifier() {
- return parent.getIdentifier();
- }
-
- /**
- * Sets the target primary shard and initiates a CreateTransaction try.
- */
- void setPrimaryShard(PrimaryShardInfo primaryShardInfo) {
- this.primaryShardInfo = primaryShardInfo;
-
- if (getTransactionType() == TransactionType.WRITE_ONLY
- && getActorContext().getDatastoreContext().isWriteOnlyTransactionOptimizationsEnabled()) {
- ActorSelection primaryShard = primaryShardInfo.getPrimaryShardActor();
-
- LOG.debug("Tx {} Primary shard {} found - creating WRITE_ONLY transaction context",
- getIdentifier(), 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.
- transactionContextWrapper.executePriorTransactionOperations(createValidTransactionContext(
- primaryShard, String.valueOf(primaryShard.path()), primaryShardInfo.getPrimaryShardVersion()));
- } else {
- tryCreateTransaction();
- }
- }
-
- /**
- Performs a CreateTransaction try async.
- */
- private void tryCreateTransaction() {
- LOG.debug("Tx {} Primary shard {} found - trying create transaction", getIdentifier(),
- primaryShardInfo.getPrimaryShardActor());
-
- Object serializedCreateMessage = new CreateTransaction(getIdentifier(), getTransactionType().ordinal(),
- primaryShardInfo.getPrimaryShardVersion()).toSerializable();
-
- Future<Object> createTxFuture = getActorContext().executeOperationAsync(
- primaryShardInfo.getPrimaryShardActor(), serializedCreateMessage, createTxMessageTimeout);
-
- createTxFuture.onComplete(new OnComplete<Object>() {
- @Override
- public void onComplete(Throwable failure, Object response) {
- onCreateTransactionComplete(failure, response);
- }
- }, getActorContext().getClientDispatcher());
- }
-
- private void tryFindPrimaryShard() {
- LOG.debug("Tx {} Retrying findPrimaryShardAsync for shard {}", getIdentifier(), shardName);
-
- this.primaryShardInfo = null;
- Future<PrimaryShardInfo> findPrimaryFuture = getActorContext().findPrimaryShardAsync(shardName);
- findPrimaryFuture.onComplete(new OnComplete<PrimaryShardInfo>() {
- @Override
- public void onComplete(final Throwable failure, final PrimaryShardInfo newPrimaryShardInfo) {
- onFindPrimaryShardComplete(failure, newPrimaryShardInfo);
- }
- }, getActorContext().getClientDispatcher());
- }
-
- private void onFindPrimaryShardComplete(final Throwable failure, final PrimaryShardInfo newPrimaryShardInfo) {
- if (failure == null) {
- this.primaryShardInfo = newPrimaryShardInfo;
- tryCreateTransaction();
- } else {
- LOG.debug("Tx {}: Find primary for shard {} failed", getIdentifier(), shardName, failure);
-
- onCreateTransactionComplete(failure, null);
- }
- }
-
- private void onCreateTransactionComplete(Throwable failure, Object response) {
- // An AskTimeoutException will occur if the local shard forwards to an unavailable remote leader or
- // the cached remote leader actor is no longer available.
- boolean retryCreateTransaction = primaryShardInfo != null
- && (failure instanceof NoShardLeaderException || failure instanceof AskTimeoutException);
-
- // Schedule a retry unless we're out of retries. Note: totalCreateTxTimeout is volatile as it may
- // be written by different threads however not concurrently, therefore decrementing it
- // non-atomically here is ok.
- if (retryCreateTransaction && totalCreateTxTimeout > 0) {
- long scheduleInterval = CREATE_TX_TRY_INTERVAL_IN_MS;
- if (failure instanceof AskTimeoutException) {
- // Since we use the createTxMessageTimeout for the CreateTransaction request and it timed
- // out, subtract it from the total timeout. Also since the createTxMessageTimeout period
- // has already elapsed, we can immediately schedule the retry (10 ms is virtually immediate).
- totalCreateTxTimeout -= createTxMessageTimeout.duration().toMillis();
- scheduleInterval = 10;
- }
-
- totalCreateTxTimeout -= scheduleInterval;
-
- LOG.debug("Tx {}: create tx on shard {} failed with exception \"{}\" - scheduling retry in {} ms",
- getIdentifier(), shardName, failure, scheduleInterval);
-
- getActorContext().getActorSystem().scheduler().scheduleOnce(
- FiniteDuration.create(scheduleInterval, TimeUnit.MILLISECONDS),
- this::tryFindPrimaryShard, getActorContext().getClientDispatcher());
- return;
- }
-
- createTransactionContext(failure, response);
- }
-
- private void createTransactionContext(Throwable failure, Object response) {
- // 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", getIdentifier(), failure);
-
- Throwable resultingEx = failure;
- if (failure instanceof AskTimeoutException) {
- resultingEx = new ShardLeaderNotRespondingException(String.format(
- "Could not create a %s transaction on shard %s. The shard leader isn't responding.",
- parent.getType(), shardName), failure);
- } else if (!(failure instanceof NoShardLeaderException)) {
- resultingEx = new Exception(String.format(
- "Error creating %s transaction on shard %s", parent.getType(), shardName), failure);
- }
-
- localTransactionContext = new NoOpTransactionContext(resultingEx, getIdentifier());
- } else if (CreateTransactionReply.isSerializedType(response)) {
- localTransactionContext = createValidTransactionContext(
- CreateTransactionReply.fromSerializable(response));
- } else {
- IllegalArgumentException exception = new IllegalArgumentException(String.format(
- "Invalid reply type %s for CreateTransaction", response.getClass()));
-
- localTransactionContext = new NoOpTransactionContext(exception, getIdentifier());
- }
-
- transactionContextWrapper.executePriorTransactionOperations(localTransactionContext);
- }
-
- private TransactionContext createValidTransactionContext(CreateTransactionReply reply) {
- LOG.debug("Tx {} Received {}", getIdentifier(), reply);
-
- return createValidTransactionContext(getActorContext().actorSelection(reply.getTransactionPath()),
- reply.getTransactionPath(), primaryShardInfo.getPrimaryShardVersion());
- }
-
- private TransactionContext createValidTransactionContext(ActorSelection transactionActor, String transactionPath,
- short remoteTransactionVersion) {
- final TransactionContext ret = new RemoteTransactionContext(transactionContextWrapper.getIdentifier(),
- transactionActor, getActorContext(), remoteTransactionVersion, transactionContextWrapper.getLimiter());
-
- if (parent.getType() == TransactionType.READ_ONLY) {
- TransactionContextCleanup.track(parent, ret);
- }
-
- return ret;
- }
-}
-