Design Requirements

By default, state is assumed to be null, unless otherwise specified, until service discovery runs. For example, if a particular role does not have state monitoring rules or service discovery rules, no state will be displayed for an application and no health indicator icon will be displayed.

Once a component has been discovered by MOM service discovery, state will be green until reset. If state cannot be determined for a component, it is recommended that a yellow or red state be displayed.

The primary requirement for state is that every health check that checks for an unhealthy state, must also check for a healthy state. It should not be possible for a state role to turn red without another rule to set the role green when the problem is resolved.

Note

Failure to determine health is a yellow or red state. For example, if a critical component is unavailable and other state checks cannot proceed, you should show these components as yellow.

Every rule must be able to change state from red to green and back again.