2 * Copyright (c) 2015 Brocade Communications Systems, Inc. and others. All rights reserved.
3 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
5 * This program and the accompanying materials are made available under the
6 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
7 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.controller.cluster.datastore;
11 import akka.actor.ActorSelection;
12 import akka.dispatch.OnComplete;
13 import com.google.common.base.Preconditions;
14 import java.util.concurrent.TimeUnit;
15 import org.opendaylight.controller.cluster.datastore.compat.PreLithiumTransactionContextImpl;
16 import org.opendaylight.controller.cluster.datastore.exceptions.NoShardLeaderException;
17 import org.opendaylight.controller.cluster.datastore.identifiers.TransactionIdentifier;
18 import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
19 import org.opendaylight.controller.cluster.datastore.messages.CreateTransactionReply;
20 import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
21 import org.slf4j.Logger;
22 import org.slf4j.LoggerFactory;
23 import scala.concurrent.Future;
24 import scala.concurrent.duration.FiniteDuration;
27 * Handles creation of TransactionContext instances for remote transactions. This class creates
28 * remote transactions, if necessary, by sending CreateTransaction messages with retries, up to a limit,
29 * if the shard doesn't have a leader yet. This is done by scheduling a retry task after a short delay.
31 * The end result from a completed CreateTransaction message is a TransactionContext that is
32 * used to perform transaction operations. Transaction operations that occur before the
33 * CreateTransaction completes are cache via a TransactionContextWrapper and executed once the
34 * CreateTransaction completes, successfully or not.
36 final class RemoteTransactionContextSupport {
37 private static final Logger LOG = LoggerFactory.getLogger(RemoteTransactionContextSupport.class);
40 * Time interval in between transaction create retries.
42 private static final FiniteDuration CREATE_TX_TRY_INTERVAL = FiniteDuration.create(1, TimeUnit.SECONDS);
44 private final TransactionProxy parent;
45 private final String shardName;
48 * The target primary shard.
50 private volatile ActorSelection primaryShard;
51 private volatile int createTxTries;
53 private final TransactionContextWrapper transactionContextAdapter;
55 RemoteTransactionContextSupport(final TransactionContextWrapper transactionContextAdapter, final TransactionProxy parent,
56 final String shardName) {
57 this.parent = Preconditions.checkNotNull(parent);
58 this.shardName = shardName;
59 this.transactionContextAdapter = transactionContextAdapter;
60 createTxTries = (int) (parent.getActorContext().getDatastoreContext().
61 getShardLeaderElectionTimeout().duration().toMillis() /
62 CREATE_TX_TRY_INTERVAL.toMillis());
65 String getShardName() {
69 private TransactionType getTransactionType() {
70 return parent.getType();
73 private ActorContext getActorContext() {
74 return parent.getActorContext();
77 private OperationLimiter getOperationLimiter() {
78 return parent.getLimiter();
81 private TransactionIdentifier getIdentifier() {
82 return parent.getIdentifier();
86 * Sets the target primary shard and initiates a CreateTransaction try.
88 void setPrimaryShard(ActorSelection primaryShard) {
89 this.primaryShard = primaryShard;
91 if (getTransactionType() == TransactionType.WRITE_ONLY &&
92 getActorContext().getDatastoreContext().isWriteOnlyTransactionOptimizationsEnabled()) {
93 LOG.debug("Tx {} Primary shard {} found - creating WRITE_ONLY transaction context",
94 getIdentifier(), primaryShard);
96 // For write-only Tx's we prepare the transaction modifications directly on the shard actor
97 // to avoid the overhead of creating a separate transaction actor.
98 // FIXME: can't assume the shard version is LITHIUM_VERSION - need to obtain it somehow.
99 transactionContextAdapter.executePriorTransactionOperations(createValidTransactionContext(this.primaryShard,
100 this.primaryShard.path().toString(), DataStoreVersions.LITHIUM_VERSION));
102 tryCreateTransaction();
107 * Performs a CreateTransaction try async.
109 private void tryCreateTransaction() {
110 if(LOG.isDebugEnabled()) {
111 LOG.debug("Tx {} Primary shard {} found - trying create transaction", getIdentifier(), primaryShard);
114 Object serializedCreateMessage = new CreateTransaction(getIdentifier().toString(),
115 getTransactionType().ordinal(), getIdentifier().getChainId()).toSerializable();
117 Future<Object> createTxFuture = getActorContext().executeOperationAsync(primaryShard, serializedCreateMessage);
119 createTxFuture.onComplete(new OnComplete<Object>() {
121 public void onComplete(Throwable failure, Object response) {
122 onCreateTransactionComplete(failure, response);
124 }, getActorContext().getClientDispatcher());
127 private void onCreateTransactionComplete(Throwable failure, Object response) {
128 if(failure instanceof NoShardLeaderException) {
129 // There's no leader for the shard yet - schedule and try again, unless we're out
130 // of retries. Note: createTxTries is volatile as it may be written by different
131 // threads however not concurrently, therefore decrementing it non-atomically here
133 if(--createTxTries > 0) {
134 LOG.debug("Tx {} Shard {} has no leader yet - scheduling create Tx retry",
135 getIdentifier(), shardName);
137 getActorContext().getActorSystem().scheduler().scheduleOnce(CREATE_TX_TRY_INTERVAL,
141 tryCreateTransaction();
143 }, getActorContext().getClientDispatcher());
148 createTransactionContext(failure, response);
151 private void createTransactionContext(Throwable failure, Object response) {
152 // Create the TransactionContext from the response or failure. Store the new
153 // TransactionContext locally until we've completed invoking the
154 // TransactionOperations. This avoids thread timing issues which could cause
155 // out-of-order TransactionOperations. Eg, on a modification operation, if the
156 // TransactionContext is non-null, then we directly call the TransactionContext.
157 // However, at the same time, the code may be executing the cached
158 // TransactionOperations. So to avoid thus timing, we don't publish the
159 // TransactionContext until after we've executed all cached TransactionOperations.
160 TransactionContext localTransactionContext;
161 if(failure != null) {
162 LOG.debug("Tx {} Creating NoOpTransaction because of error", getIdentifier(), failure);
164 localTransactionContext = new NoOpTransactionContext(failure, getIdentifier(), getOperationLimiter());
165 } else if (CreateTransactionReply.SERIALIZABLE_CLASS.equals(response.getClass())) {
166 localTransactionContext = createValidTransactionContext(
167 CreateTransactionReply.fromSerializable(response));
169 IllegalArgumentException exception = new IllegalArgumentException(String.format(
170 "Invalid reply type %s for CreateTransaction", response.getClass()));
172 localTransactionContext = new NoOpTransactionContext(exception, getIdentifier(), getOperationLimiter());
175 transactionContextAdapter.executePriorTransactionOperations(localTransactionContext);
178 private TransactionContext createValidTransactionContext(CreateTransactionReply reply) {
179 LOG.debug("Tx {} Received {}", getIdentifier(), reply);
181 return createValidTransactionContext(getActorContext().actorSelection(reply.getTransactionPath()),
182 reply.getTransactionPath(), reply.getVersion());
185 private TransactionContext createValidTransactionContext(ActorSelection transactionActor, String transactionPath,
186 short remoteTransactionVersion) {
187 // TxActor is always created where the leader of the shard is.
188 // Check if TxActor is created in the same node
189 boolean isTxActorLocal = getActorContext().isPathLocal(transactionPath);
190 final TransactionContext ret;
192 if (remoteTransactionVersion < DataStoreVersions.LITHIUM_VERSION) {
193 ret = new PreLithiumTransactionContextImpl(transactionPath, transactionActor, getIdentifier(),
194 getActorContext(), isTxActorLocal, remoteTransactionVersion, parent.getLimiter());
196 ret = new RemoteTransactionContext(transactionActor, getIdentifier(), getActorContext(),
197 isTxActorLocal, remoteTransactionVersion, parent.getLimiter());
200 if(parent.getType() == TransactionType.READ_ONLY) {
201 TransactionContextCleanup.track(this, ret);