2 * Copyright (c) 2015, 2017 Cisco Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.ovsdb.hwvtepsouthbound.transactions.md;
10 import com.google.common.util.concurrent.FutureCallback;
11 import com.google.common.util.concurrent.Futures;
12 import com.google.common.util.concurrent.ListenableFuture;
13 import com.google.common.util.concurrent.MoreExecutors;
14 import com.google.common.util.concurrent.ThreadFactoryBuilder;
15 import java.util.ArrayList;
16 import java.util.HashMap;
17 import java.util.Iterator;
18 import java.util.List;
20 import java.util.concurrent.BlockingQueue;
21 import java.util.concurrent.ExecutorService;
22 import java.util.concurrent.Executors;
23 import java.util.concurrent.LinkedBlockingQueue;
24 import java.util.concurrent.ThreadFactory;
25 import org.opendaylight.controller.md.sal.binding.api.BindingTransactionChain;
26 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
27 import org.opendaylight.controller.md.sal.binding.api.ReadWriteTransaction;
28 import org.opendaylight.controller.md.sal.common.api.data.AsyncTransaction;
29 import org.opendaylight.controller.md.sal.common.api.data.TransactionChain;
30 import org.opendaylight.controller.md.sal.common.api.data.TransactionChainListener;
31 import org.slf4j.Logger;
32 import org.slf4j.LoggerFactory;
35 * Copied over as-is from southbound plugin. Good candidate to be common
36 * when refactoring code.
38 public class TransactionInvokerImpl implements TransactionInvoker,TransactionChainListener, Runnable, AutoCloseable,
39 Thread.UncaughtExceptionHandler {
40 private static final Logger LOG = LoggerFactory.getLogger(TransactionInvokerImpl.class);
41 private static final int QUEUE_SIZE = 10000;
43 private final DataBroker db;
44 private final BlockingQueue<TransactionCommand> inputQueue = new LinkedBlockingQueue<>(QUEUE_SIZE);
45 private final BlockingQueue<AsyncTransaction<?, ?>> failedTransactionQueue = new LinkedBlockingQueue<>(QUEUE_SIZE);
46 private final BlockingQueue<ReadWriteTransaction> successfulTransactionQueue =
47 new LinkedBlockingQueue<>(QUEUE_SIZE);
48 private final ExecutorService executor;
50 private Map<ReadWriteTransaction,TransactionCommand> transactionToCommand = new HashMap<>();
51 private List<ReadWriteTransaction> pendingTransactions = new ArrayList<>();
52 private BindingTransactionChain chain;
53 //This is made volatile as it is accessed from uncaught exception handler thread also
54 private volatile ReadWriteTransaction transactionInFlight = null;
55 private Iterator<TransactionCommand> commandIterator = null;
57 public TransactionInvokerImpl(final DataBroker db) {
59 this.chain = db.createTransactionChain(this);
60 ThreadFactory threadFact = new ThreadFactoryBuilder().setNameFormat("transaction-invoker-impl-%d")
61 .setUncaughtExceptionHandler(this).build();
62 executor = Executors.newSingleThreadExecutor(threadFact);
63 //Using the execute method here so that un caught exception handler gets triggered upon exception.
64 //The other way to do it is using submit method and wait on the future to catch any exceptions
65 executor.execute(this);
69 public void invoke(final TransactionCommand command) {
70 // TODO what do we do if queue is full?
71 if (!inputQueue.offer(command)) {
72 LOG.error("inputQueue is full (size: {}) - could not offer {}", inputQueue.size(), command);
77 public void onTransactionChainFailed(final TransactionChain<?, ?> txChain,
78 final AsyncTransaction<?, ?> transaction, final Throwable cause) {
79 offerFailedTransaction(transaction);
83 public void onTransactionChainSuccessful(final TransactionChain<?, ?> txChain) {
90 forgetSuccessfulTransactions();
92 List<TransactionCommand> commands = null;
94 commands = extractCommands();
95 } catch (InterruptedException e) {
96 LOG.warn("Extracting commands was interrupted.", e);
99 commandIterator = commands.iterator();
101 while (commandIterator.hasNext()) {
102 TransactionCommand command = commandIterator.next();
103 final ReadWriteTransaction transaction = chain.newReadWriteTransaction();
104 transactionInFlight = transaction;
105 recordPendingTransaction(command, transaction);
106 command.execute(transaction);
107 ListenableFuture<Void> ft = transaction.submit();
108 command.setTransactionResultFuture(ft);
109 Futures.addCallback(ft, new FutureCallback<Void>() {
111 public void onSuccess(final Void result) {
112 if (!successfulTransactionQueue.offer(transaction)) {
113 LOG.error("successfulTransactionQueue is full (size: {}) - could not offer {}",
114 successfulTransactionQueue.size(), transaction);
119 public void onFailure(final Throwable throwable) {
120 // NOOP - handled by failure of transaction chain
122 }, MoreExecutors.directExecutor());
124 transactionInFlight = null;
125 } catch (IllegalStateException e) {
126 if (transactionInFlight != null) {
127 // TODO: This method should distinguish exceptions on which the command should be
128 // retried from exceptions on which the command should NOT be retried.
129 // Then it should retry only the commands which should be retried, otherwise
130 // this method will retry commands which will never be successful forever.
131 offerFailedTransaction(transactionInFlight);
133 transactionInFlight = null;
134 LOG.warn("Failed to process an update notification from OVS.", e);
139 private void offerFailedTransaction(final AsyncTransaction<?, ?> transaction) {
140 if (!failedTransactionQueue.offer(transaction)) {
141 LOG.warn("failedTransactionQueue is full (size: {})", failedTransactionQueue.size());
145 private List<TransactionCommand> extractResubmitCommands() {
146 AsyncTransaction<?, ?> transaction = failedTransactionQueue.poll();
147 List<TransactionCommand> commands = new ArrayList<>();
148 if (transaction != null) {
149 int index = pendingTransactions.lastIndexOf(transaction);
150 //This logic needs to be revisited. Is it ok to resubmit these things again ?
151 //are these operations idempotent ?
152 //Does the transaction chain execute n+1th if nth one threw error ?
153 List<ReadWriteTransaction> transactions =
154 pendingTransactions.subList(index, pendingTransactions.size() - 1);
155 for (ReadWriteTransaction tx: transactions) {
156 commands.add(transactionToCommand.get(tx));
158 resetTransactionQueue();
160 if (commandIterator != null) {
161 while (commandIterator.hasNext()) {
162 commands.add(commandIterator.next());
168 private void resetTransactionQueue() {
170 chain = db.createTransactionChain(this);
171 pendingTransactions = new ArrayList<>();
172 transactionToCommand = new HashMap<>();
173 failedTransactionQueue.clear();
174 successfulTransactionQueue.clear();
177 private void recordPendingTransaction(final TransactionCommand command,
178 final ReadWriteTransaction transaction) {
179 transactionToCommand.put(transaction, command);
180 pendingTransactions.add(transaction);
183 private List<TransactionCommand> extractCommands() throws InterruptedException {
184 List<TransactionCommand> commands = extractResubmitCommands();
185 if (!commands.isEmpty() && inputQueue.isEmpty()) {
186 //we got some commands to be executed let us not sit and wait on empty queue
189 //pull commands from queue if not empty , otherwise wait for commands to be placed in queue.
190 commands.addAll(extractCommandsFromQueue());
194 private List<TransactionCommand> extractCommandsFromQueue() throws InterruptedException {
195 List<TransactionCommand> result = new ArrayList<>();
196 TransactionCommand command = inputQueue.take();
198 inputQueue.drainTo(result);
202 private void forgetSuccessfulTransactions() {
203 ReadWriteTransaction transaction = successfulTransactionQueue.poll();
204 while (transaction != null) {
205 pendingTransactions.remove(transaction);
206 transactionToCommand.remove(transaction);
207 transaction = successfulTransactionQueue.poll();
212 public void close() throws Exception {
214 this.executor.shutdown();
218 public void uncaughtException(final Thread thread, final Throwable ex) {
219 LOG.error("Failed to execute hwvtep transact command, re-submitting the transaction again", ex);
220 if (transactionInFlight != null) {
221 offerFailedTransaction(transactionInFlight);
223 transactionInFlight = null;
224 executor.execute(this);