Werk #17729: Fix misbehaving check plugins after a reboot

Component	Site management
Title	Fix misbehaving check plugins after a reboot
Date	Mar 25, 2025
Level	Trivial Change
Class	Bug Fix
Compatibility	Compatible - no manual interaction needed
Checkmk versions & editions	2.5.0b1 Not yet released Checkmk Raw (CRE), Checkmk Enterprise (CEE), Checkmk Cloud (CCE), Checkmk MSP (CME) 2.4.0b3 Checkmk Raw (CRE), Checkmk Enterprise (CEE), Checkmk Cloud (CCE), Checkmk MSP (CME) 2.3.0p30 Checkmk Raw (CRE), Checkmk Enterprise (CEE), Checkmk Cloud (CCE), Checkmk MSP (CME)

The check plugins are allowed to store data for the next check cycle via the value store. During omd umount these data structures are persisted. Due to a regression introduced in Werk #15872, the same data would be loaded after every reboot. This meant that check plugins would receive data, which was not from the previous check cycle, but rather from the last time omd umount was ran.

In the 2.4 this could result in the following exception

JSONDecodeError (Expecting property name enclosed in double quotes: line 1 column 2 (char 1))

The same issue also affects piggyback data. With this Werk, the use of outdated data is fixed.

Note, after a reboot the value store is likely to be empty. The check plugins need to correctly initialize their data on the first check cycle.

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