Field Notes
If Monitoring Fails With the Service, It Was Never Enough - Observability is only useful if enough of it survives the failure it is supposed to explain.
Categories:
[Field Notes],
[Observability]
Monitoring systems are usually designed around a simple question: what information do we need in order to understand the state of our infrastructure and applications? We collect metrics, logs, traces, application telemetry and synthetic measurements, and then use them to build a picture of how the e...
A Green Patch Run Proves Less Than We Think - Why installing updates is only one part of a successful maintenance process.
Categories:
[Field Notes],
[Automation]
A routine maintenance operation finishes successfully. The automation reports that every host was reachable, packages were updated and no tasks failed. The execution summary is green, the logs are available and the maintenance activity appears complete.
From an automation perspective, everything worked.
From an operational perspective, however, we have only confirmed that the requested actions were executed successfully. We have not necessarily established that the updated systems are running the expected software, that their applications recovered correctly or that the services they provide remain fully functional.
This distinction is particularly relevant as infrastructure teams increasingly automate operating system maintenance using tools such as Ansible. Installing packages is relatively straightforward. Establishing that the maintenance operation achieved its intended outcome requires a different level of attention.
The challenge is not necessarily making automation more sophisticated. It is deciding what we actually consider a successful result.