Werk #6149

ComponentChecks & Agents
Titleps: The linux ps check CPU utilization calculation changed since 1.4.0p27
Date2018-05-22 11:45:55
Check_MK EditionCheck_MK Raw Edition (CRE)
Check_MK Version1.4.0p34,1.6.0i1
Level1 - Trivial Change
ClassBug Fix
CompatibilityCompatible - no manual interaction needed

The calculation of the CPU utilization of processes on linux systems was not taking the number of CPU cores into account for a long time. This results in CPU utilizations reported with more than 100%, up to 100%*CPU-cores. For example in case 3 processes use 3 of 6 cores at 100%, this resulted in a usage of 300%.

The intention of the change in 1.4.0p27 was to make the windows and linux ps checks both take the number of CPU cores into account and cap the usage at 100%. The problem with this change is that all possibly existing thresholds that have been configured for the old scheme will not work anymore with the new scheme.

We have now reverted the changes version 1.4.0p27 introduced to get the old behavior back.

In a future release, we will finally make the switch to the new scheme. But this will be done in a compatible way where the already configured thresholds will still work.