Class StableMasterHealthIndicatorService

java.lang.Object
org.elasticsearch.cluster.coordination.StableMasterHealthIndicatorService
All Implemented Interfaces:
HealthIndicatorService

public class StableMasterHealthIndicatorService extends Object implements HealthIndicatorService
This indicator reports the health of master stability. If we have had a master within the last 30 seconds, and that master has not changed more than 3 times in the last 30 minutes, then this will report GREEN. If we have had a master within the last 30 seconds, but that master has changed more than 3 times in the last 30 minutes (and that is confirmed by checking with the last-known master), then this will report YELLOW. If we have not had a master within the last 30 seconds, then this will will report RED with one exception. That exception is when: (1) no node is elected master, (2) this node is not master eligible, (3) some node is master eligible, (4) we ask a master-eligible node to run this indicator, and (5) it comes back with a result that is not RED. Since this indicator needs to be able to run when there is no master at all, it does not depend on the dedicated health node (which requires the existence of a master).