feat: Use Retry when claiming against deadlock exceptions

When claims hit doctrine "RetryableException", which basically are
DeadlockExceptions and LockWaitTimeoutException, an exponential retry
mechaism tries a couple of times.

Author: stephanschuler

Classes/Domain/Scheduler.php

@@ -5,12 +5,14 @@
 namespace Netlogix\JobQueue\Scheduled\Domain;
 
 use DateTimeImmutable;
+use Doctrine\DBAL\Exception\RetryableException;
 use Doctrine\DBAL\Types\Types;
 use InvalidArgumentException;
 use Neos\Flow\Utility\Algorithms;
 use Netlogix\JobQueue\Scheduled\Domain\Model\ScheduledJob;
 use Netlogix\JobQueue\Scheduled\DueDateCalculation\TimeBaseForDueDateCalculation;
 use Netlogix\JobQueue\Scheduled\Service\Connection;
+use Netlogix\Retry\Retry;
 
 use function array_filter;
 use function in_array;
@@ -108,20 +110,26 @@ public function next(string $groupName): ?ScheduledJob
             SET claimed = :claimed
             WHERE claimed = ""
         ';
-        $this->dbal
-            ->executeQuery(
-                $update,
-                [
-                    'now' => $this->timeBaseForDueDateCalculation->getNow(),
-                    'groupname' => $groupName,
-                    'claimed' => $claim,
-                ],
-                [
-                    'now' => Types::DATETIME_IMMUTABLE,
-                    'groupname' => Types::STRING,
-                    'claimed' => Types::STRING,
-                ]
-            );
+        (new Retry())
+            /**
+             * @see http://backoffcalculator.com/?attempts=5&rate=1&interval=0.5
+             */
+            ->withExponentialBackoff(retryInterval: 0.5, maxRetries: 5)
+            ->onExceptionsOfType(RetryableException::class)
+            ->task(fn() => $this->dbal
+                ->executeQuery(
+                    $update,
+                    [
+                        'now' => $this->timeBaseForDueDateCalculation->getNow(),
+                        'groupname' => $groupName,
+                        'claimed' => $claim,
+                    ],
+                    [
+                        'now' => Types::DATETIME_IMMUTABLE,
+                        'groupname' => Types::STRING,
+                        'claimed' => Types::STRING,
+                    ]
+                ));
 
         $select = /** @lang MySQL */ '
             SELECT identifier, duedate, queue, job, incarnation, claimed

Tests/Functional/RetrievingTest.php

@@ -4,8 +4,13 @@
 namespace Netlogix\JobQueue\Scheduled\Tests\Functional;
 
 use DateTimeImmutable;
+use Doctrine\DBAL\Exception\DeadlockException;
+use Doctrine\ORM\EntityManagerInterface;
+use Neos\Flow\Persistence\Doctrine\PersistenceManager;
+use Neos\Flow\Persistence\PersistenceManagerInterface;
 use Netlogix\JobQueue\Scheduled\Domain\Model\ScheduledJob;
 use Netlogix\JobQueue\Scheduled\Domain\Scheduler;
+use Netlogix\JobQueue\Scheduled\Service\Connection;
 
 class RetrievingTest extends TestCase
 {
@@ -117,6 +122,34 @@ public function Scheduled_jobs_can_be_retrieved_only_once(): void
         self::assertNull($retrievedJob2);
     }
 
+
+    /**
+     * @test
+     */
+    public function Retry_claiming_when_deadlock_exceptions_happen(): void
+    {
+        $connection = self::createMock(Connection::class);
+        $connection->expects(self::any())
+            ->method('executeQuery')
+            ->willThrowException(self::createStub(DeadlockException::class));
+
+        $this->scheduler->injectConnection($connection);
+
+        $start = microtime(true);
+        try {
+            $this->scheduler->next(Scheduler::DEFAULT_GROUP_NAME);
+        } catch (DeadlockException $e) {
+        }
+        $end = microtime(true);
+        $delta = $end - $start;
+
+        self::assertInstanceOf(DeadlockException::class, $e);
+
+        // guesstimated value is 15 and something.
+        self::assertGreaterThan(14, $delta);
+        self::assertLessThan(18, $delta);
+    }
+
     /**
      * @test
      */

composer.json

@@ -13,6 +13,7 @@
         "doctrine/orm": "^2.6",
         "flowpack/jobqueue-common": "^3.0",
         "neos/flow": "~8.3",
+        "netlogix/retry": "~1.0",
         "php": "~8.2 || ~8.3"
     },
     "require-dev": {