Werk #19223: Windows agent: Process agent updater output consistently
| Component | Agent bakery | ||
| Title | Windows agent: Process agent updater output consistently | ||
| Date | Jul 27, 2026 | ||
| Level | Trivial Change | ||
| Class | Bug Fix | ||
| Compatibility | Compatible - no manual interaction needed | ||
| Checkmk versions & editions |
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This werk extends werk #19216.
Even after werk #19216, the Windows agent handled the empty output of the agent
updater plugin (cmk_update_agent.checkmk.py) through an internal special-case
marker. Under certain timing conditions the updater process could exit before the
agent was able to read its exit code. The agent then treated the process state as
unknown, killed it, and logged a corresponding error. This inconsistent handling
could still produce spurious process-kill log entries and unreliable cache updates.
Starting with this release, the Windows agent processes the agent updater output in a single, consistent way. It writes a fixed marker line to the plugin output so the result is never empty, which removes the need for the previous special-case handling. The agent also correctly recognizes when the updater process has already exited and its exit code can no longer be retrieved, treating this as a normal termination instead of killing the process. As a result, the updater cache is updated reliably and the agent no longer emits spurious process-kill messages.
The marker line is emitted as a <<<cmk_update_agent_alive>>> section. It is not
consumed by any check on the Checkmk server side and requires no configuration.