feature #50270 [Scheduler] add JitterTrigger (kbond)

fabpot · fabpot · commit 3b29817d7d2b · 2023-05-10T08:54:36.000+02:00
This PR was merged into the 6.3 branch. Discussion ---------- [Scheduler] add `JitterTrigger` | Q | A | ------------- | --- | Branch? | 6.4 | Bug fix? | no | New feature? | yes | Deprecations? | no | Tickets | #49806 | License | MIT | Doc PR | n/a I think this is what `@vtsykun` was trying to accomplish with #49806. FreeBSD has a `-jitter` option that does the same thing so I think there's precedent. From the (https://man.freebsd.org/cgi/man.cgi?cron): > -j jitter > Enable time jitter. Prior to executing commands, cron will sleep a random number of seconds in the range from 0 to jitter. ~This will not affect superuser jobs (see -J).~ A value for jitter must be between 0 and 60 inclusive. Default is 0, which effectively disables time jitter. > This option can help to smooth down system load spikes during mo- ments when a lot of jobs are likely to start at once, e.g., at the beginning of the first minute of each hour. Usage: ```php // defaults to 0-60 seconds $schedule->add(RecurringMessage::cron('`@daily`', $message1)->withJitter()); // customize the max seconds (0-30) $schedule->add(RecurringMessage::cron('`@daily`', $message1)->withJitter(30)); ``` Commits ------- b0d984b [Scheduler] add `JitterTrigger`
diff --git a/src/Symfony/Component/Scheduler/RecurringMessage.php b/src/Symfony/Component/Scheduler/RecurringMessage.php
@@ -14,6 +14,7 @@
 use Symfony\Component\Scheduler\Exception\InvalidArgumentException;
 use Symfony\Component\Scheduler\Trigger\CronExpressionTrigger;
 use Symfony\Component\Scheduler\Trigger\DateIntervalTrigger;
+use Symfony\Component\Scheduler\Trigger\JitterTrigger;
 use Symfony\Component\Scheduler\Trigger\TriggerInterface;
 
 /**
@@ -59,6 +60,11 @@ public static function trigger(TriggerInterface $trigger, object $message): self
         return new self($trigger, $message);
     }
 
+    public function withJitter(int $maxSeconds = 60): self
+    {
+        return new self(new JitterTrigger($this->trigger, $maxSeconds), $this->message);
+    }
+
     public function getMessage(): object
     {
         return $this->message;
diff --git a/src/Symfony/Component/Scheduler/Tests/Trigger/JitterTriggerTest.php b/src/Symfony/Component/Scheduler/Tests/Trigger/JitterTriggerTest.php
@@ -0,0 +1,42 @@
+<?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\Scheduler\Tests\Trigger;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Scheduler\Trigger\JitterTrigger;
+use Symfony\Component\Scheduler\Trigger\TriggerInterface;
+
+class JitterTriggerTest extends TestCase
+{
+    public function testCanAddJitter()
+    {
+        $time = new \DateTimeImmutable();
+        $inner = $this->createMock(TriggerInterface::class);
+        $inner->method('getNextRunDate')->willReturn($time);
+
+        $trigger = new JitterTrigger($inner);
+
+        $values = array_map(
+            fn () => (int) $trigger->getNextRunDate($time)?->getTimestamp(),
+            array_fill(0, 100, null)
+        );
+
+        foreach ($values as $value) {
+            $this->assertGreaterThanOrEqual($time->getTimestamp(), $value);
+            $this->assertLessThanOrEqual($time->getTimestamp() + 60, $value);
+        }
+
+        $values = array_unique($values);
+
+        $this->assertGreaterThan(1, \count($values));
+    }
+}
diff --git a/src/Symfony/Component/Scheduler/Trigger/JitterTrigger.php b/src/Symfony/Component/Scheduler/Trigger/JitterTrigger.php
@@ -0,0 +1,39 @@
+<?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\Scheduler\Trigger;
+
+/**
+ * @author Kevin Bond <kevinbond@gmail.com>
+ */
+final class JitterTrigger implements TriggerInterface
+{
+    /**
+     * @param positive-int $maxSeconds
+     */
+    public function __construct(private readonly TriggerInterface $trigger, private readonly int $maxSeconds = 60)
+    {
+    }
+
+    public function __toString(): string
+    {
+        return sprintf('%s with 0-%d second jitter', $this->trigger, $this->maxSeconds);
+    }
+
+    public function getNextRunDate(\DateTimeImmutable $run): ?\DateTimeImmutable
+    {
+        if (!$nextRun = $this->trigger->getNextRunDate($run)) {
+            return null;
+        }
+
+        return $nextRun->add(new \DateInterval(sprintf('PT%sS', random_int(0, $this->maxSeconds))));
+    }
+}
