diff --git a/System/Crontab/Zookeeper.php b/System/Crontab/Zookeeper.php
index 89b50b13..47a0ec4b 100644
--- a/System/Crontab/Zookeeper.php
+++ b/System/Crontab/Zookeeper.php
@@ -65,6 +65,7 @@ class Zookeeper extends Process
         try {
             $params['action'] = 'crontab';
             if (($handler = $redis->get('crontab:' . $value)) === false) {
+                var_dump($handler);
                 return;
             }
             $params['handler'] = swoole_unserialize($handler);