symfony · fabpot · May 3, 2020 · Jan 23, 2020
diff --git a/src/Symfony/Component/Messenger/CHANGELOG.md b/src/Symfony/Component/Messenger/CHANGELOG.md
@@ -8,6 +8,7 @@ CHANGELOG
 * Moved Doctrine transport to package `symfony/doctrine-messenger`. All classes in `Symfony\Component\Messenger\Transport\Doctrine` have been moved to `Symfony\Component\Messenger\Bridge\Doctrine\Transport`
 * Moved RedisExt transport to package `symfony/redis-messenger`. All classes in `Symfony\Component\Messenger\Transport\RedisExt` have been moved to `Symfony\Component\Messenger\Bridge\Redis\Transport`
 * Added support for passing a `\Throwable` argument to `RetryStrategyInterface` methods. This allows to define strategies based on the reason of the handling failure.
+ * Added `StopWorkerOnFailureLimitListener` to stop the worker after a specified amount of failed messages is reached.

 5.0.0
 -----

diff --git a/src/Symfony/Component/Messenger/Command/ConsumeMessagesCommand.php b/src/Symfony/Component/Messenger/Command/ConsumeMessagesCommand.php
@@ -23,6 +23,7 @@
 use Symfony\Component\Console\Question\ChoiceQuestion;
 use Symfony\Component\Console\Style\SymfonyStyle;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
+use Symfony\Component\Messenger\EventListener\StopWorkerOnFailureLimitListener;
 use Symfony\Component\Messenger\EventListener\StopWorkerOnMemoryLimitListener;
 use Symfony\Component\Messenger\EventListener\StopWorkerOnMessageLimitListener;
 use Symfony\Component\Messenger\EventListener\StopWorkerOnTimeLimitListener;
@@ -64,6 +65,7 @@ protected function configure(): void
            ->setDefinition([
                new InputArgument('receivers', InputArgument::IS_ARRAY, 'Names of the receivers/transports to consume in order of priority', $defaultReceiverName ? [$defaultReceiverName] : []),
                new InputOption('limit', 'l', InputOption::VALUE_REQUIRED, 'Limit the number of received messages'),
+                new InputOption('failure-limit', 'f', InputOption::VALUE_REQUIRED, 'The number of failed messages the worker can consume'),
                new InputOption('memory-limit', 'm', InputOption::VALUE_REQUIRED, 'The memory limit the worker can consume'),
                new InputOption('time-limit', 't', InputOption::VALUE_REQUIRED, 'The time limit in seconds the worker can run'),
                new InputOption('sleep', null, InputOption::VALUE_REQUIRED, 'Seconds to sleep before asking for new messages after no messages were found', 1),
@@ -82,6 +84,10 @@ protected function configure(): void
 Use the --limit option to limit the number of messages received:

    <info>php %command.full_name% <receiver-name> --limit=10</info>
+
+Use the --failure-limit option to stop the worker when the given number of failed messages is reached:
+
+    <info>php %command.full_name% <receiver-name> --failure-limit=2</info>

 Use the --memory-limit option to stop the worker if it exceeds a given memory usage limit. You can use shorthand byte values [K, M or G]:

@@ -152,6 +158,11 @@ protected function execute(InputInterface $input, OutputInterface $output)
            $this->eventDispatcher->addSubscriber(new StopWorkerOnMessageLimitListener($limit, $this->logger));
        }

+        if ($failureLimit = $input->getOption('failure-limit')) {
+            $stopsWhen[] = "reached {$failureLimit} failed messages";
+            $this->eventDispatcher->addSubscriber(new StopWorkerOnFailureLimitListener($failureLimit, $this->logger));
+        }
+
        if ($memoryLimit = $input->getOption('memory-limit')) {
            $stopsWhen[] = "exceeded {$memoryLimit} of memory";
            $this->eventDispatcher->addSubscriber(new StopWorkerOnMemoryLimitListener($this->convertToBytes($memoryLimit), $this->logger));

diff --git a/src/Symfony/Component/Messenger/EventListener/StopWorkerOnFailureLimitListener.php b/src/Symfony/Component/Messenger/EventListener/StopWorkerOnFailureLimitListener.php
@@ -0,0 +1,63 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Messenger\EventListener;
+
+use Psr\Log\LoggerInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\Messenger\Event\WorkerMessageFailedEvent;
+use Symfony\Component\Messenger\Event\WorkerRunningEvent;
+use Symfony\Component\Messenger\Exception\InvalidArgumentException;
+
+/**
+ * @author Michel Hunziker <info@michelhunziker.com>
+ */
+class StopWorkerOnFailureLimitListener implements EventSubscriberInterface
+{
+    private $maximumNumberOfFailures;
+    private $logger;
+    private $failedMessages = 0;
+
+    public function __construct(int $maximumNumberOfFailures, LoggerInterface $logger = null)
+    {
+        $this->maximumNumberOfFailures = $maximumNumberOfFailures;
+        $this->logger = $logger;
+
+        if ($maximumNumberOfFailures <= 0) {
+            throw new InvalidArgumentException('Failure limit must be greater than zero.');
+        }
+    }
+
+    public function onMessageFailed(WorkerMessageFailedEvent $event): void
+    {
+        ++$this->failedMessages;
+    }
+
+    public function onWorkerRunning(WorkerRunningEvent $event): void
+    {
+        if (!$event->isWorkerIdle() && $this->failedMessages >= $this->maximumNumberOfFailures) {
+            $this->failedMessages = 0;
+            $event->getWorker()->stop();
+
+            if (null !== $this->logger) {
+                $this->logger->info('Worker stopped due to limit of {count} failed message(s) is reached', ['count' => $this->maximumNumberOfFailures]);
+            }
+        }
+    }
+
+    public static function getSubscribedEvents(): array
+    {
+        return [
+            WorkerMessageFailedEvent::class => 'onMessageFailed',
+            WorkerRunningEvent::class => 'onWorkerRunning',
+        ];
+    }
+}
diff --git a/src/Symfony/Component/Messenger/Tests/EventListener/StopWorkerOnFailureLimitListenerTest.php b/src/Symfony/Component/Messenger/Tests/EventListener/StopWorkerOnFailureLimitListenerTest.php
@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Messenger\Tests\EventListener;
+
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Symfony\Component\Messenger\Envelope;
+use Symfony\Component\Messenger\Event\WorkerMessageFailedEvent;
+use Symfony\Component\Messenger\Event\WorkerRunningEvent;
+use Symfony\Component\Messenger\EventListener\StopWorkerOnFailureLimitListener;
+use Symfony\Component\Messenger\Tests\Fixtures\DummyMessage;
+use Symfony\Component\Messenger\Worker;
+use Throwable;
+
+class StopWorkerOnFailureLimitListenerTest extends TestCase
+{
+    /**
+     * @dataProvider countProvider
+     */
+    public function testWorkerStopsWhenMaximumCountReached(int $max, bool $shouldStop): void
+    {
+        $worker = $this->createMock(Worker::class);
+        $worker->expects($shouldStop ? $this->atLeastOnce() : $this->never())->method('stop');
+
+        $failedEvent = $this->createFailedEvent();
+        $runningEvent = new WorkerRunningEvent($worker, false);
+
+        $failureLimitListener = new StopWorkerOnFailureLimitListener($max);
+        // simulate three messages (of which 2 failed)
+        $failureLimitListener->onMessageFailed($failedEvent);
+        $failureLimitListener->onWorkerRunning($runningEvent);
+
+        $failureLimitListener->onWorkerRunning($runningEvent);
+
+        $failureLimitListener->onMessageFailed($failedEvent);
+        $failureLimitListener->onWorkerRunning($runningEvent);
+    }
+
+    public function countProvider(): iterable
+    {
+        yield [1, true];
+        yield [2, true];
+        yield [3, false];
+        yield [4, false];
+    }
+
+    public function testWorkerLogsMaximumCountReachedWhenLoggerIsGiven(): void
+    {
+        $logger = $this->createMock(LoggerInterface::class);
+        $logger->expects($this->once())->method('info')
+            ->with(
+                $this->equalTo('Worker stopped due to limit of {count} failed message(s) is reached'),
+                $this->equalTo(['count' => 1])
+            );
+
+        $worker = $this->createMock(Worker::class);
+        $event = new WorkerRunningEvent($worker, false);
+
+        $failureLimitListener = new StopWorkerOnFailureLimitListener(1, $logger);
+        $failureLimitListener->onMessageFailed($this->createFailedEvent());
+        $failureLimitListener->onWorkerRunning($event);
+    }
+
+    private function createFailedEvent(): WorkerMessageFailedEvent
+    {
+        $envelope = new Envelope(new DummyMessage('hello'));
+
+        return new WorkerMessageFailedEvent($envelope, 'default', $this->createMock(Throwable::class));
+    }
+}