org.apache.spark.launcher

Interface SparkAppHandle

public interface SparkAppHandle

A handle to a running Spark application.

Provides runtime information about the underlying Spark application, and actions to control it.

Since:

1.6.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	SparkAppHandle.Listener Listener for updates to a handle's state.
static class	SparkAppHandle.State Represents the application's state.

Method Summary

Modifier and Type	Method and Description
void	addListener(SparkAppHandle.Listener l) Adds a listener to be notified of changes to the handle's information.
void	disconnect() Disconnects the handle from the application, without stopping it.
String	getAppId() Returns the application ID, or null if not yet known.
java.util.Optional<Throwable>	getError() If the application failed due to an error, return the underlying error.
SparkAppHandle.State	getState() Returns the current application state.
void	kill() Tries to kill the underlying application.
void	stop() Asks the application to stop.

Method Detail

addListener

void addListener(SparkAppHandle.Listener l)

Adds a listener to be notified of changes to the handle's information. Listeners will be called from the thread processing updates from the application, so they should avoid blocking or long-running operations.

Parameters:

l - Listener to add.

getState

SparkAppHandle.State getState()

Returns the current application state.

getAppId

String getAppId()

Returns the application ID, or null if not yet known.

stop

void stop()

Asks the application to stop. This is best-effort, since the application may fail to receive or act on the command. Callers should watch for a state transition that indicates the application has really stopped.

kill

void kill()

Tries to kill the underlying application. Implies disconnect(). This will not send a stop() message to the application, so it's recommended that users first try to stop the application cleanly and only resort to this method if that fails.

disconnect

void disconnect()

Disconnects the handle from the application, without stopping it. After this method is called, the handle will not be able to communicate with the application anymore.

getError

java.util.Optional<Throwable> getError()

If the application failed due to an error, return the underlying error. If the app succeeded, this method returns an empty Optional.