start directory to begin.
A health check for startup allows applications to define startup probes that verify whether deployed application is fully initialized before the liveness probe takes over. This check is useful for applications that require additional startup time on their first initialization. The
@Startup annotation must be applied on a HealthCheck implementation to define a startup check procedure. Otherwise, this annotation is ignored. This startup check verifies that the cpu usage is below 95%. If more than 95% of the cpu is used, a status of
DOWN is returned.
A health check for liveness allows third party services to determine whether the application is running. If this procedure fails, the application can be stopped. The
@Liveness annotation must be applied on a HealthCheck implementation to define a Liveness check procedure. Otherwise, this annotation is ignored. This liveness check verifies that the heap memory usage is below 90% of the maximum memory. If more than 90% of the maximum memory is used, a status of
DOWN is returned.
inventory microservice is healthy only when the
system microservice is available. To add this check to the
/health/ready endpoint, create a class that is annotated with the
@Readiness annotation and implements the
HealthCheck interface. A Health Check for readiness allows third party services to know whether the application is ready to process requests. The
@Readiness annotation must be applied on a HealthCheck implementation to define a readiness check procedure. Otherwise, this annotation is ignored.
This health check verifies that the
system microservice is available at
system-service host name is accessible only from inside the cluster; you can’t access it yourself. If it’s available, then it returns an
UP status. Similarly, if it’s unavailable then it returns a
DOWN status. When the status is
DOWN, the microservice is considered to be unhealthy.
The health checks for the
system microservice were already been implemented. The
system microservice was set up to become unhealthy for 60 seconds when a specific endpoint is called. This endpoint has been provided for you to observe the results of an unhealthy pod and how Kubernetes reacts.