Merge pull request #3809 from appwrite/fix-function-scheduling

Fix functon scheduling loop logic, and double-loop prevention

app/config/collections.php

@@ -2148,6 +2148,17 @@ $collections = [
                 'array' => false,
                 'filters' => [],
             ],
+            [
+                '$id' => ID::custom('scheduleUpdatedAt'), // Used to fix duplicate executions bug. Can be removed once new queue library is used
+                'type' => Database::VAR_DATETIME,
+                'format' => '',
+                'size' => 0,
+                'signed' => false,
+                'required' => false,
+                'default' => null,
+                'array' => false,
+                'filters' => ['datetime'],
+            ],
             [
                 '$id' => ID::custom('schedulePrevious'),
                 'type' => Database::VAR_DATETIME,

app/controllers/api/functions.php

@@ -84,6 +84,7 @@ App::post('/v1/functions')
             'deployment' => '',
             'events' => $events,
             'schedule' => $schedule,
+            'scheduleUpdatedAt' => DateTime::now(),
             'schedulePrevious' => null,
             'scheduleNext' => null,
             'timeout' => $timeout,
@@ -445,6 +446,7 @@ App::put('/v1/functions/:functionId')
         $cron = (!empty($function->getAttribute('deployment')) && !empty($schedule)) ? new CronExpression($schedule) : null;
         $next = (!empty($function->getAttribute('deployment')) && !empty($schedule)) ? DateTime::format($cron->getNextRunDate()) : null;
 
+        $scheduleUpdatedAt = $schedule !== $original ? DateTime::now() : $function->getAttribute('scheduleUpdatedAt');
         $enabled ??= $function->getAttribute('enabled', true);
 
         $function = $dbForProject->updateDocument('functions', $function->getId(), new Document(array_merge($function->getArrayCopy(), [
@@ -452,6 +454,7 @@ App::put('/v1/functions/:functionId')
             'name' => $name,
             'events' => $events,
             'schedule' => $schedule,
+            'scheduleUpdatedAt' => $scheduleUpdatedAt,
             'scheduleNext' => $next,
             'timeout' => $timeout,
             'enabled' => $enabled,

app/workers/functions.php

@@ -129,7 +129,7 @@ class FunctionsV1 extends Worker
                 break;
 
             case 'schedule':
-                $scheduleOriginal = $execution->getAttribute('scheduleOriginal', '');
+                $functionOriginal = $function;
                 /*
                  * 1. Get Original Task
                  * 2. Check for updates
@@ -150,21 +150,25 @@ class FunctionsV1 extends Worker
                     throw new Exception('Function not found (' . $function->getId() . ')');
                 }
 
-                if ($scheduleOriginal && $scheduleOriginal !== $function->getAttribute('schedule')) { // Schedule has changed from previous run, ignore this run.
+                if ($functionOriginal->getAttribute('schedule') !== $function->getAttribute('schedule')) { // Schedule has changed from previous run, ignore this run.
+                    return;
+                }
+
+                if ($functionOriginal->getAttribute('scheduleUpdatedAt') !== $function->getAttribute('scheduleUpdatedAt')) { // Double execution due to rapid cron changes, ignore this run.
                     return;
                 }
 
                 $cron = new CronExpression($function->getAttribute('schedule'));
                 $next = DateTime::format($cron->getNextRunDate());
 
-                $function
+                $function = $function
                     ->setAttribute('scheduleNext', $next)
                     ->setAttribute('schedulePrevious', DateTime::now());
 
                 $function = $database->updateDocument(
                     'functions',
                     $function->getId(),
-                    $function->setAttribute('scheduleNext', $next)
+                    $function
                 );
 
                 $reschedule = new Func();