org.apache.samza.runtime

Class ApplicationRunner

java.lang.Object

org.apache.samza.runtime.ApplicationRunner

@InterfaceStability.Unstable
public abstract class ApplicationRunner
extends java.lang.Object

The primary means of managing execution of the StreamApplication at runtime.

Field Summary

Fields

Modifier and Type	Field and Description
protected Config	config

Constructor Summary

Constructors

Constructor and Description
ApplicationRunner(Config config)

Method Summary

Modifier and Type	Method and Description
static ApplicationRunner	fromConfig(Config config) Static method to load the ApplicationRunner
abstract StreamSpec	getStreamSpec(java.lang.String streamId) Constructs a StreamSpec from the configuration for the specified streamId.
abstract void	kill(StreamApplication streamApp) Kill the Samza jobs represented by StreamApplication It is non-blocking so it doesn't wait for the application stopping.
abstract void	run(StreamApplication streamApp) Deploy and run the Samza jobs to execute StreamApplication.
abstract ApplicationStatus	status(StreamApplication streamApp) Get the collective status of the Samza jobs represented by StreamApplication.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

config

protected final Config config

Constructor Detail

ApplicationRunner

public ApplicationRunner(Config config)

Method Detail

fromConfig

public static ApplicationRunner fromConfig(Config config)

Static method to load the ApplicationRunner

Parameters:

config - configuration passed in to initialize the Samza processes

Returns:

the configure-driven ApplicationRunner to run the user-defined stream applications

run

public abstract void run(StreamApplication streamApp)

Deploy and run the Samza jobs to execute StreamApplication. It is non-blocking so it doesn't wait for the application running.

Parameters:

streamApp - the user-defined StreamApplication object

kill

public abstract void kill(StreamApplication streamApp)

Kill the Samza jobs represented by StreamApplication It is non-blocking so it doesn't wait for the application stopping.

Parameters:

streamApp - the user-defined StreamApplication object

status

public abstract ApplicationStatus status(StreamApplication streamApp)

Get the collective status of the Samza jobs represented by StreamApplication. Returns ApplicationRunner running if all jobs are running.

Parameters:

streamApp - the user-defined StreamApplication object

Returns:

the status of the application

getStreamSpec

public abstract StreamSpec getStreamSpec(java.lang.String streamId)

Constructs a StreamSpec from the configuration for the specified streamId. The stream configurations are read from the following properties in the config: streams.{$streamId}.*
All properties matching this pattern are assumed to be system-specific with two exceptions. The following two properties are Samza properties which are used to bind the stream to a system and a physical resource on that system.

• samza.system - The name of the System on which this stream will be used. If this property isn't defined the stream will be associated with the System defined in job.default.system
• samza.physical.name - The system-specific name for this stream. It could be a file URN, topic name, or other identifer. If this property isn't defined the physical.name will be set to the streamId

Parameters:

streamId - The logical identifier for the stream in Samza.

Returns:

The StreamSpec instance.