alluxio.master.service

Interface SimpleService

All Known Implementing Classes:

JvmMonitorService, MetricsService, NoopService, RpcServerService, RpcServerStandbyGrpcService, WebServerService

public interface SimpleService

Defines a simple start/promote/demote/stop interface for interacting with simple Alluxio master components such as the web server, metrics server, rpc server, etc...

Method Summary

Modifier and Type	Method and Description
void	demote() Demotes the service back to NodeState.STANDBY state.
void	promote() Promotes the service to NodeState.PRIMARY state.
void	start() Starts the service.
void	stop() Stops the service altogether and cleans up any state left.

Method Detail

start

void start()

Starts the service. Leaves the service in NodeState.STANDBY state. Leaves the service in the same state as demote(). Can only be called once.

promote

void promote()

Promotes the service to NodeState.PRIMARY state. Can only be called on a started service (i.e. start() must precede this method). Can only be called in NodeState.STANDBY state. Can be called multiple times (e.g. a service is promoted, then demoted, then promoted again).

demote

void demote()

Demotes the service back to NodeState.STANDBY state. Can only be called on a started service (i.e. start() must precede this method). Can only be called in NodeState.PRIMARY state (i.e. promote() must precede this method). Can be called multiple times (e.g. a service is promoted, then demoted, then promoted again, and demoted again).

stop

void stop()

Stops the service altogether and cleans up any state left. If start() has not been called on this service this method should be a noop. Can only be called once.