X-Git-Url: https://git.opendaylight.org/gerrit/gitweb?p=controller.git;a=blobdiff_plain;f=opendaylight%2Fmd-sal%2Fsal-distributed-datastore%2Fsrc%2Fmain%2Fjava%2Forg%2Fopendaylight%2Fcontroller%2Fcluster%2Fdatastore%2FTransactionChainProxy.java;h=b93f540f20783b74288b7112056883d6a535c9cf;hp=cf261cbd2af103b70f3dfce9885903a88ee293e6;hb=c796596b5c46b5203c30b143e6282662e66c5642;hpb=412db94945c5db5d2da918f5e23bd3abcecc4d10 diff --git a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionChainProxy.java b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionChainProxy.java index cf261cbd2a..b93f540f20 100644 --- a/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionChainProxy.java +++ b/opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/TransactionChainProxy.java @@ -1,110 +1,178 @@ /* - * Copyright (c) 2014 Cisco 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.Futures; +import akka.dispatch.OnComplete; import com.google.common.base.Preconditions; -import java.util.Collections; +import java.util.ArrayList; +import java.util.Collection; import java.util.List; -import java.util.concurrent.atomic.AtomicInteger; +import java.util.Map.Entry; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ConcurrentMap; +import java.util.concurrent.atomic.AtomicReferenceFieldUpdater; +import java.util.function.Function; +import javax.annotation.Nonnull; +import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier; +import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier; import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain; -import org.opendaylight.controller.cluster.datastore.utils.ActorContext; +import org.opendaylight.controller.cluster.datastore.messages.PrimaryShardInfo; import org.opendaylight.controller.md.sal.common.api.data.TransactionChainClosedException; import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction; import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction; import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain; import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction; +import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; import scala.concurrent.Future; +import scala.concurrent.Promise; /** - * TransactionChainProxy acts as a proxy for a DOMStoreTransactionChain created on a remote shard + * A chain of {@link TransactionProxy}s. It allows a single open transaction to be open + * at a time. For remote transactions, it also tracks the outstanding readiness requests + * towards the shard and unblocks operations only after all have completed. */ -public class TransactionChainProxy implements DOMStoreTransactionChain { - - private interface State { - boolean isReady(); +final class TransactionChainProxy extends AbstractTransactionContextFactory implements DOMStoreTransactionChain { + private static abstract class State { + /** + * Check if it is okay to allocate a new transaction. + * @throws IllegalStateException if a transaction may not be allocated. + */ + abstract void checkReady(); - List> getPreviousReadyFutures(); + /** + * Return the future which needs to be waited for before shard information + * is returned (which unblocks remote transactions). + * @return Future to wait for, or null of no wait is necessary + */ + abstract Future previousFuture(); } - private static class Allocated implements State { - private final ChainedTransactionProxy transaction; + private static abstract class Pending extends State { + private final TransactionIdentifier transaction; + private final Future previousFuture; + + Pending(final TransactionIdentifier transaction, final Future previousFuture) { + this.previousFuture = previousFuture; + this.transaction = Preconditions.checkNotNull(transaction); + } + + @Override + final Future previousFuture() { + return previousFuture; + } + + final TransactionIdentifier getIdentifier() { + return transaction; + } + } - Allocated(ChainedTransactionProxy transaction) { - this.transaction = transaction; + private static final class Allocated extends Pending { + Allocated(final TransactionIdentifier transaction, final Future previousFuture) { + super(transaction, previousFuture); } @Override - public boolean isReady() { - return transaction.isReady(); + void checkReady() { + throw new IllegalStateException(String.format("Previous transaction %s is not ready yet", getIdentifier())); + } + } + + private static final class Submitted extends Pending { + Submitted(final TransactionIdentifier transaction, final Future previousFuture) { + super(transaction, previousFuture); } @Override - public List> getPreviousReadyFutures() { - return transaction.getReadyFutures(); + void checkReady() { + // Okay to allocate } } - private static abstract class AbstractDefaultState implements State { + private static abstract class DefaultState extends State { @Override - public List> getPreviousReadyFutures() { - return Collections.emptyList(); + final Future previousFuture() { + return null; } } - private static final State IDLE_STATE = new AbstractDefaultState() { + private static final State IDLE_STATE = new DefaultState() { @Override - public boolean isReady() { - return true; + void checkReady() { + // Okay to allocate } }; - private static final State CLOSED_STATE = new AbstractDefaultState() { + private static final State CLOSED_STATE = new DefaultState() { @Override - public boolean isReady() { + void checkReady() { throw new TransactionChainClosedException("Transaction chain has been closed"); } }; - private static final AtomicInteger counter = new AtomicInteger(0); + private static final Logger LOG = LoggerFactory.getLogger(TransactionChainProxy.class); + private static final AtomicReferenceFieldUpdater STATE_UPDATER = + AtomicReferenceFieldUpdater.newUpdater(TransactionChainProxy.class, State.class, "currentState"); - private final ActorContext actorContext; - private final String transactionChainId; + private final TransactionContextFactory parent; private volatile State currentState = IDLE_STATE; - public TransactionChainProxy(ActorContext actorContext) { - this.actorContext = actorContext; - transactionChainId = actorContext.getCurrentMemberName() + "-txn-chain-" + counter.incrementAndGet(); + /** + * This map holds Promise instances for each read-only tx. It is used to maintain ordering of tx creates + * wrt to read-only tx's between this class and a LocalTransactionChain since they're bridged by + * asynchronous futures. Otherwise, in the following scenario, eg: + * + * 1) Create write tx1 on chain + * 2) do write and submit + * 3) Create read-only tx2 on chain and issue read + * 4) Create write tx3 on chain, do write but do not submit + * + * if the sequence/timing is right, tx3 may create its local tx on the LocalTransactionChain before tx2, + * which results in tx2 failing b/c tx3 isn't ready yet. So maintaining ordering prevents this issue + * (see Bug 4774). + *

+ * A Promise is added via newReadOnlyTransaction. When the parent class completes the primary shard + * lookup and creates the TransactionContext (either success or failure), onTransactionContextCreated is + * called which completes the Promise. A write tx that is created prior to completion will wait on the + * Promise's Future via findPrimaryShard. + */ + private final ConcurrentMap> priorReadOnlyTxPromises = new ConcurrentHashMap<>(); + + TransactionChainProxy(final TransactionContextFactory parent, final LocalHistoryIdentifier historyId) { + super(parent.getActorContext(), historyId); + this.parent = parent; } public String getTransactionChainId() { - return transactionChainId; + return getHistoryId().toString(); } @Override public DOMStoreReadTransaction newReadOnlyTransaction() { - State localState = currentState; - checkReadyState(localState); - - return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_ONLY, - transactionChainId, localState.getPreviousReadyFutures()); + currentState.checkReady(); + TransactionProxy transactionProxy = new TransactionProxy(this, TransactionType.READ_ONLY); + priorReadOnlyTxPromises.put(transactionProxy.getIdentifier(), Futures.promise()); + return transactionProxy; } @Override public DOMStoreReadWriteTransaction newReadWriteTransaction() { - actorContext.acquireTxCreationPermit(); - return allocateWriteTransaction(TransactionProxy.TransactionType.READ_WRITE); + getActorContext().acquireTxCreationPermit(); + return allocateWriteTransaction(TransactionType.READ_WRITE); } @Override public DOMStoreWriteTransaction newWriteOnlyTransaction() { - actorContext.acquireTxCreationPermit(); - return allocateWriteTransaction(TransactionProxy.TransactionType.WRITE_ONLY); + getActorContext().acquireTxCreationPermit(); + return allocateWriteTransaction(TransactionType.WRITE_ONLY); } @Override @@ -112,24 +180,156 @@ public class TransactionChainProxy implements DOMStoreTransactionChain { currentState = CLOSED_STATE; // Send a close transaction chain request to each and every shard - actorContext.broadcast(new CloseTransactionChain(transactionChainId).toSerializable()); + + getActorContext().broadcast(new Function() { + @Override + public Object apply(Short version) { + return new CloseTransactionChain(getHistoryId().toString(), version).toSerializable(); + } + }); } - private ChainedTransactionProxy allocateWriteTransaction(TransactionProxy.TransactionType type) { + private TransactionProxy allocateWriteTransaction(final TransactionType type) { State localState = currentState; + localState.checkReady(); + + final TransactionProxy ret = new TransactionProxy(this, type); + currentState = new Allocated(ret.getIdentifier(), localState.previousFuture()); + return ret; + } + + @Override + protected LocalTransactionChain factoryForShard(final String shardName, final ActorSelection shardLeader, final DataTree dataTree) { + final LocalTransactionChain ret = new LocalTransactionChain(this, shardLeader, dataTree); + LOG.debug("Allocated transaction chain {} for shard {} leader {}", ret, shardName, shardLeader); + return ret; + } + + /** + * This method is overridden to ensure the previous Tx's ready operations complete + * before we initiate the next Tx in the chain to avoid creation failures if the + * previous Tx's ready operations haven't completed yet. + */ + @SuppressWarnings({ "unchecked", "rawtypes" }) + @Override + protected Future findPrimaryShard(final String shardName, final TransactionIdentifier txId) { + // Read current state atomically + final State localState = currentState; - checkReadyState(localState); + // There are no outstanding futures, shortcut + Future previous = localState.previousFuture(); + if (previous == null) { + return combineFutureWithPossiblePriorReadOnlyTxFutures(parent.findPrimaryShard(shardName, txId), txId); + } + + final String previousTransactionId; + + if(localState instanceof Pending){ + previousTransactionId = ((Pending) localState).getIdentifier().toString(); + LOG.debug("Tx: {} - waiting for ready futures with pending Tx {}", txId, previousTransactionId); + } else { + previousTransactionId = ""; + LOG.debug("Waiting for ready futures on chain {}", getTransactionChainId()); + } + + previous = combineFutureWithPossiblePriorReadOnlyTxFutures(previous, txId); + + // Add a callback for completion of the combined Futures. + final Promise returnPromise = Futures.promise(); + + final OnComplete onComplete = new OnComplete() { + @Override + public void onComplete(final Throwable failure, final Object notUsed) { + if (failure != null) { + // A Ready Future failed so fail the returned Promise. + LOG.error("Tx: {} - ready future failed for previous Tx {}", txId, previousTransactionId); + returnPromise.failure(failure); + } else { + LOG.debug("Tx: {} - previous Tx {} readied - proceeding to FindPrimaryShard", + txId, previousTransactionId); + + // Send the FindPrimaryShard message and use the resulting Future to complete the + // returned Promise. + returnPromise.completeWith(parent.findPrimaryShard(shardName, txId)); + } + } + }; + + previous.onComplete(onComplete, getActorContext().getClientDispatcher()); + return returnPromise.future(); + } + + private Future combineFutureWithPossiblePriorReadOnlyTxFutures(final Future future, + final TransactionIdentifier txId) { + if(!priorReadOnlyTxPromises.containsKey(txId) && !priorReadOnlyTxPromises.isEmpty()) { + Collection>> priorReadOnlyTxPromiseEntries = + new ArrayList<>(priorReadOnlyTxPromises.entrySet()); + if(priorReadOnlyTxPromiseEntries.isEmpty()) { + return future; + } + + List> priorReadOnlyTxFutures = new ArrayList<>(priorReadOnlyTxPromiseEntries.size()); + for(Entry> entry: priorReadOnlyTxPromiseEntries) { + LOG.debug("Tx: {} - waiting on future for prior read-only Tx {}", txId, entry.getKey()); + priorReadOnlyTxFutures.add(entry.getValue().future()); + } - // Pass the ready Futures from the previous Tx. - ChainedTransactionProxy txProxy = new ChainedTransactionProxy(actorContext, type, - transactionChainId, localState.getPreviousReadyFutures()); + Future> combinedFutures = Futures.sequence(priorReadOnlyTxFutures, + getActorContext().getClientDispatcher()); - currentState = new Allocated(txProxy); + final Promise returnPromise = Futures.promise(); + final OnComplete> onComplete = new OnComplete>() { + @Override + public void onComplete(final Throwable failure, final Iterable notUsed) { + LOG.debug("Tx: {} - prior read-only Tx futures complete", txId); - return txProxy; + // Complete the returned Promise with the original Future. + returnPromise.completeWith(future); + } + }; + + combinedFutures.onComplete(onComplete, getActorContext().getClientDispatcher()); + return returnPromise.future(); + } else { + return future; + } + } + + @Override + protected void onTransactionReady(final TransactionIdentifier transaction, final Collection> cohortFutures) { + final State localState = currentState; + Preconditions.checkState(localState instanceof Allocated, "Readying transaction %s while state is %s", transaction, localState); + final TransactionIdentifier currentTx = ((Allocated)localState).getIdentifier(); + Preconditions.checkState(transaction.equals(currentTx), "Readying transaction %s while %s is allocated", transaction, currentTx); + + // Transaction ready and we are not waiting for futures -- go to idle + if (cohortFutures.isEmpty()) { + currentState = IDLE_STATE; + return; + } + + // Combine the ready Futures into 1 + final Future> combined = Futures.sequence(cohortFutures, getActorContext().getClientDispatcher()); + + // Record the we have outstanding futures + final State newState = new Submitted(transaction, combined); + currentState = newState; + + // Attach a completion reset, but only if we do not allocate a transaction + // in-between + combined.onComplete(new OnComplete>() { + @Override + public void onComplete(final Throwable arg0, final Iterable arg1) { + STATE_UPDATER.compareAndSet(TransactionChainProxy.this, newState, IDLE_STATE); + } + }, getActorContext().getClientDispatcher()); } - private void checkReadyState(State state) { - Preconditions.checkState(state.isReady(), "Previous transaction is not ready yet"); + @Override + protected void onTransactionContextCreated(@Nonnull TransactionIdentifier transactionId) { + Promise promise = priorReadOnlyTxPromises.remove(transactionId); + if(promise != null) { + promise.success(null); + } } }