stddev
Trips when the inconsistency of a metric exceeds a threshold.
How it works
Measures metric variance or jitter. High standard deviation indicates unpredictable behavior, which often precedes systemic failure.
When to use
- Detecting unstable performance despite a healthy average.
- Catching services oscillating between fast and slow states.
- Identifying micro-burst traffic patterns.
When not to use
- Metrics that are naturally volatile by design.
State explanations
closed
System behavior is stable and predictable.
half open
Confirming the system has regained steady-state behavior.
open
Performance is erratic, indicating the system is under stress.