Invoke-IcingaCheckDiskHealth Error on Windows Cluster after a Node Reboot

[audiocoach]

In a Windows Cluster environment with a quorum disk the Invoke-IcingaCheckDiskHealth plugin throws the following error after a node reboot and failback of the quorum disk to the rebooted host.

Icinga Plugin execution error was thrown during API request:

Ausnahme beim Aufrufen von "Value" mit 0 Argument(en):  "Ausnahme beim Aufrufen von "Value" mit 0 Argument(en):  "Ausnahme beim Aufrufen von "NextValue" mit 0 Argument(en):  "Instanz 1 ist in der angegebenen Kategorie nicht vorhanden."""

The error only occurs in the icinga web gui. If we execute the command locally on the host, there is no error.

I assume it has something to do with the fact that the quorum disk is always owned by one cluster node. If you reboot this node the quorum disk fails over to another node. After the node has rebooted the quorum disk is still owned by one of the other cluster nodes.
Please note: At this time there is no error!!!

But now when you fail back the quorum disk to the rebooted cluster node the check goes to an unknown state and throwing the error mentioned above. Probably because the performance counters for this quorum disk are missing because at the time icinga started on the rebooted cluster node the quorum disk wan't owned by it.
A manual restart of icinga is needed in order to make it work again.

But if so why doesn't the error occur if you execute the check locally on the rebooted node ...

[LordHepipud]

I assume this issue is caused by the performance counters. The names of the counters are cached internally, once fetched but are not updated, once loaded.

You can reproduce this issue by adding a USB drive with a partition to the system. Add the USB drive and restart Icinga for Windows. Afterwards execute the check over the API.

You will now be able to see the USB device. If you remove the device, the plugin might break or work, depending on if the performance counters are checked first.

If you start Icinga for Windows before inserting the USB device, the disk check will not include the device.

This is an issue we somehow need to address, while not tanking the performance of the plugin execution or causing the system load to explode.

[LordHepipud]

This is also a long-term issue/feature which is missing #11

[LordHepipud]

#828