A Docker Healthcheck Must Test the Dependency You Actually Need
A process can be alive while the service contract its neighbors depend on is broken.
healthcheck
Process Health and Protocol Health Are Different in VoIP
A running SIP or RTP process is necessary but not sufficient evidence that calls can establish and carry media.
Running Is Not the Same as Healthy
Container process state only proves that PID 1 exists; readiness has to test the behavior the dependency actually needs.
Healthcheck Duration Can Warn Before Healthcheck Failure
A probe may keep returning success while taking progressively longer, showing a dependency slowdown before Docker marks the container unhealthy.
Running Containers Are Not Healthy Containers
The Docker daemon can report a container as running even when the application inside it has stopped serving useful traffic.
Notification Endpoint Health Needs Direct Monitoring
Delivery counters only change when an alert is sent, so a quiet system could leave a dead notification service unnoticed for hours.