Package org.apache.hadoop.yarn.server.nodemanager.health

Interface HealthReporter

All Known Implementing Classes:

ExceptionReporter, LocalDirsHandlerService, NodeHealthCheckerService, NodeHealthScriptRunner, TimedHealthReporterService

public interface HealthReporter

Interface providing information about the health of a service. Associated pieces of information:

• whether the service is healthy (isHealthy())
• report of the healthiness (getHealthReport())
• latest timestamp of the health check (getLastHealthReportTime())

Classes implementing this interface are used in NodeHealthCheckerService. Developers are discouraged to implement new Java-based health scripts, they should rather try to implement it as a script and use the NodeHealthScriptRunner implementation.

See Also:

• TimedHealthReporterService
• LocalDirsHandlerService

Method Summary

Modifier and Type	Method	Description
String	getHealthReport()	Returns output from health check.
long	getLastHealthReportTime()	Returns time stamp when node health check was last run.
boolean	isHealthy()	Gets whether the node is healthy or not.

Method Details

isHealthy

boolean isHealthy()

Gets whether the node is healthy or not.

Returns:

true if node is healthy

getHealthReport

String getHealthReport()

Returns output from health check. If node is healthy then an empty string is returned.

Returns:

output from health check

getLastHealthReportTime

long getLastHealthReportTime()

Returns time stamp when node health check was last run.

Returns:

timestamp when node health script was last run