org.apache.twill.api

Interface ServiceController

All Known Subinterfaces:

TwillController

public interface ServiceController

This interface is for controlling a remote running service.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ServiceController.TerminationStatus Enum to represent termination status of the application when it completed.

Method Summary

Modifier and Type	Method and Description
void	awaitTerminated() Waits for termination of the remote service.
void	awaitTerminated(long timeout, TimeUnit timeoutUnit) Waits for termination of the remote service for no more than the given timeout limit.
RunId	getRunId() Returns the RunId of the running application.
ServiceController.TerminationStatus	getTerminationStatus() Gets the termination status of the application represented by this controller.
void	kill() Requests to forcefully kill a running service.
void	onRunning(Runnable runnable, Executor executor) Attaches a Runnable that will get executed when the service is running.
void	onTerminated(Runnable runnable, Executor executor) Attaches a Runnable that will get executed when the serivce is terminated.
Future<Command>	sendCommand(Command command) Sends a user command to the running application.
Future<Command>	sendCommand(String runnableName, Command command) Sends a user command to the given runnable of the running application.
Future<? extends ServiceController>	terminate() Requests to terminate the running service.

Method Detail

getRunId

RunId getRunId()

Returns the RunId of the running application.

sendCommand

Future<Command> sendCommand(Command command)

Sends a user command to the running application.

Parameters:

command - The command to send.

Returns:

A Future that will be completed when the command is successfully processed by the target application.

sendCommand

Future<Command> sendCommand(String runnableName,
                            Command command)

Sends a user command to the given runnable of the running application.

Parameters:

runnableName - Name of the TwillRunnable.

command - The command to send.

Returns:

A Future that will be completed when the command is successfully processed by the target runnable.

terminate

Future<? extends ServiceController> terminate()

Requests to terminate the running service. The service will be given chance to shutdown gracefully. This method returns immediately and caller can get the termination state through the future returned. Calling this method multiple times is allowed and a Future representing the termination state will be returned.

Returns:

a Future that represents the termination of the service. The future result will be this ServiceController. If the service terminated with a ServiceController.TerminationStatus.FAILED status, calling the Future.get() on the returning future will throw ExecutionException.

kill

void kill()

Requests to forcefully kill a running service.

onRunning

void onRunning(Runnable runnable,
               Executor executor)

Attaches a Runnable that will get executed when the service is running.

Parameters:

runnable - the Runnable to be executed when the service is running.

executor - the executor in which the runnable will be executed with.

onTerminated

void onTerminated(Runnable runnable,
                  Executor executor)

Attaches a Runnable that will get executed when the serivce is terminated.

Parameters:

runnable - the Runnable to be executed when the service is terminated.

executor - the executor in which the runnable will be executed with.

awaitTerminated

void awaitTerminated()
              throws ExecutionException

Waits for termination of the remote service.

Throws:

ExecutionException - if the service terminated due to exception.

awaitTerminated

void awaitTerminated(long timeout,
                     TimeUnit timeoutUnit)
              throws TimeoutException,
                     ExecutionException

Waits for termination of the remote service for no more than the given timeout limit.

Parameters:

timeout - the maximum time to wait

timeoutUnit - the time unit of the timeout

Throws:

TimeoutException - if the service is not terminated within the given time.

ExecutionException - if the service terminated due to exception.

getTerminationStatus

@Nullable
ServiceController.TerminationStatus getTerminationStatus()

Gets the termination status of the application represented by this controller.

Returns:

the termination status or null if the application is still running