1 Description
Due to a bug in PHP there’s a possible file descriptor leak in the scheduler. This means, that your scheduled processes might inherit file decriptors it didn’t open. Because of the software design of the scheduler, this effect can in rare cases accumulate to eat away all file descriptors of the scheduled process, which can in turn trigger bugs in your scheduled process.
Certain versions of rsync are known to hang up under those conditions.
2 Workaround
If you are affected by the problem, there’s a workaround that stops the accumulative effect. Put the following line in your node.conf:
$SCHEDULER_CMD_PREFIX = "sudo -u node nohup";
For this to work, you need sudo installed, and it must be configured allow the node user to switch to itself wihout a password, otherwise the scheduler will not work at all. The change in node.conf will be effective immediately for the next running scheduler task.