Werk #19192: Windows agent: disable WinDbg logging by default
| Component | Checks & agents | ||||
| Title | Windows agent: disable WinDbg logging by default | ||||
| Date | Mar 24, 2026 | ||||
| Level | Prominent Change | ||||
| Class | New Feature | ||||
| Compatibility | Compatible - no manual interaction needed | ||||
| Checkmk versions & editions |
|
Previously, the Windows agent sent all log messages to the Windows debugging interface (WinDbg / OutputDebugString) by default. This meant that on every production host running the Checkmk agent, log output was continuously written to the debug sink — even when no debugger was attached and nobody was monitoring it.
This behavior is undesirable in production environments for two reasons: first, OutputDebugString has a non-trivial overhead when a debugger is attached, and second, it exposes internal agent log messages to any process that listens on the debug output channel (e.g. DebugView, WinDbg).
WinDbg logging is now disabled by default. It can be re-enabled explicitly
by setting windbg: yes under global.logging in the agent configuration
file, which is appropriate for development and debugging scenarios.