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.FluentFuture;
11 import com.google.common.util.concurrent.FutureCallback;
12 import com.google.common.util.concurrent.MoreExecutors;
13 import com.google.common.util.concurrent.ThreadFactoryBuilder;
14 import java.util.ArrayList;
15 import java.util.HashMap;
16 import java.util.Iterator;
17 import java.util.List;
19 import java.util.concurrent.BlockingQueue;
20 import java.util.concurrent.ExecutorService;
21 import java.util.concurrent.Executors;
22 import java.util.concurrent.LinkedBlockingQueue;
23 import java.util.concurrent.ThreadFactory;
24 import org.checkerframework.checker.lock.qual.GuardedBy;
25 import org.opendaylight.mdsal.binding.api.DataBroker;
26 import org.opendaylight.mdsal.binding.api.ReadWriteTransaction;
27 import org.opendaylight.mdsal.binding.api.Transaction;
28 import org.opendaylight.mdsal.binding.api.TransactionChain;
29 import org.opendaylight.mdsal.binding.api.TransactionChainListener;
30 import org.slf4j.Logger;
31 import org.slf4j.LoggerFactory;
34 * Copied over as-is from southbound plugin. Good candidate to be common
35 * when refactoring code.
37 public class TransactionInvokerImpl implements TransactionInvoker,TransactionChainListener, Runnable, AutoCloseable,
38 Thread.UncaughtExceptionHandler {
39 private static final Logger LOG = LoggerFactory.getLogger(TransactionInvokerImpl.class);
40 private static final int QUEUE_SIZE = 10000;
42 private final DataBroker db;
43 private final BlockingQueue<TransactionCommand> inputQueue = new LinkedBlockingQueue<>(QUEUE_SIZE);
44 private final BlockingQueue<Transaction> failedTransactionQueue = new LinkedBlockingQueue<>(QUEUE_SIZE);
45 private final ExecutorService executor;
48 private final Map<ReadWriteTransaction,TransactionCommand> transactionToCommand = new HashMap<>();
50 private final List<ReadWriteTransaction> pendingTransactions = new ArrayList<>();
52 private TransactionChain 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 Transaction transaction, final Throwable cause) {
79 offerFailedTransaction(transaction);
83 public void onTransactionChainSuccessful(final TransactionChain txChain) {
90 final List<TransactionCommand> commands;
92 commands = extractCommands();
93 } catch (InterruptedException e) {
94 LOG.warn("Extracting commands was interrupted.", e);
97 commandIterator = commands.iterator();
99 while (commandIterator.hasNext()) {
100 executeCommand(commandIterator.next());
102 transactionInFlight = null;
103 } catch (IllegalStateException e) {
104 if (transactionInFlight != null) {
105 // TODO: This method should distinguish exceptions on which the command should be
106 // retried from exceptions on which the command should NOT be retried.
107 // Then it should retry only the commands which should be retried, otherwise
108 // this method will retry commands which will never be successful forever.
109 offerFailedTransaction(transactionInFlight);
111 transactionInFlight = null;
112 LOG.warn("Failed to process an update notification from OVS.", e);
117 private synchronized void executeCommand(final TransactionCommand command) {
118 final ReadWriteTransaction transaction = chain.newReadWriteTransaction();
119 transactionInFlight = transaction;
120 recordPendingTransaction(command, transaction);
121 command.execute(transaction);
122 FluentFuture<?> ft = transaction.commit();
123 command.setTransactionResultFuture(ft);
124 ft.addCallback(new FutureCallback<Object>() {
126 public void onSuccess(final Object result) {
127 forgetSuccessfulTransaction(transaction);
131 public void onFailure(final Throwable throwable) {
132 // NOOP - handled by failure of transaction chain
134 }, MoreExecutors.directExecutor());
137 private void offerFailedTransaction(final Transaction transaction) {
138 if (!failedTransactionQueue.offer(transaction)) {
139 LOG.warn("failedTransactionQueue is full (size: {})", failedTransactionQueue.size());
143 private List<TransactionCommand> extractResubmitCommands() {
144 List<TransactionCommand> commands = new ArrayList<>();
145 synchronized (this) {
146 Transaction transaction = failedTransactionQueue.poll();
147 if (transaction != null) {
148 int index = pendingTransactions.lastIndexOf(transaction);
149 //This logic needs to be revisited. Is it ok to resubmit these things again ?
150 //are these operations idempotent ?
151 //Does the transaction chain execute n+1th if nth one threw error ?
152 List<ReadWriteTransaction> transactions =
153 pendingTransactions.subList(index, pendingTransactions.size() - 1);
154 for (ReadWriteTransaction tx: transactions) {
155 commands.add(transactionToCommand.get(tx));
157 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.clear();
172 transactionToCommand.clear();
173 failedTransactionQueue.clear();
176 synchronized void forgetSuccessfulTransaction(final ReadWriteTransaction transaction) {
177 pendingTransactions.remove(transaction);
178 transactionToCommand.remove(transaction);
181 private synchronized void recordPendingTransaction(final TransactionCommand command,
182 final ReadWriteTransaction transaction) {
183 transactionToCommand.put(transaction, command);
184 pendingTransactions.add(transaction);
187 private List<TransactionCommand> extractCommands() throws InterruptedException {
188 List<TransactionCommand> commands = extractResubmitCommands();
189 if (!commands.isEmpty() && inputQueue.isEmpty()) {
190 //we got some commands to be executed let us not sit and wait on empty queue
193 //pull commands from queue if not empty , otherwise wait for commands to be placed in queue.
194 commands.addAll(extractCommandsFromQueue());
198 private List<TransactionCommand> extractCommandsFromQueue() throws InterruptedException {
199 List<TransactionCommand> result = new ArrayList<>();
200 TransactionCommand command = inputQueue.take();
202 inputQueue.drainTo(result);
207 public void close() throws Exception {
209 this.executor.shutdown();
213 public void uncaughtException(final Thread thread, final Throwable ex) {
214 LOG.error("Failed to execute hwvtep transact command, re-submitting the transaction again", ex);
215 if (transactionInFlight != null) {
216 offerFailedTransaction(transactionInFlight);
218 transactionInFlight = null;
219 executor.execute(this);