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Werk #19789: Fix response time levels losing millisecond values in certain rules

Component Setup
Title Fix response time levels losing millisecond values in certain rules
Date May 18, 2026
Level Trivial Change
Class Bug Fix
Compatibility Compatible - no manual interaction needed
Checkmk versions & editions
2.4.0p32 Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

When editing rules whose response time thresholds are displayed in milliseconds only (without a separate seconds field), warning and critical thresholds were silently reset to 1/1000th of their intended value after saving.

For example, a warning threshold of 1000 ms would be stored as 1.0 s on first save, but displayed as 1 ms on the next edit. Saving again would then permanently store 1 ms.

The root cause was a wrong cascade factor in the TimeSpan valuespec: when the seconds unit is not shown but the milliseconds field is, the whole-seconds value was passed to the milliseconds input with a factor of 1 instead of 1000. So 1.0 s was rendered as 1 ms. A second bug prevented rules originally created in Checkmk 2.3 from loading at all in 2.4 when a migration function was configured on the levels form spec.

The following rules are affected because they display response time thresholds in milliseconds only (i.e. without a seconds field alongside):

  • Check TCP port connection (expected response time)
  • Disk IO (read/write service time)
  • Diskstat (read/write service time, read/write wait time, average wait time)
  • MS Exchange: Database (transaction log write time), Info Store (read/write latency), RPC Client Access (RPC latency)

This has been fixed.

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