ai.grakn.engine.tasks.manager.multiqueue

Class MultiQueueTaskRunner

java.lang.Object

ai.grakn.engine.tasks.manager.multiqueue.MultiQueueTaskRunner

All Implemented Interfaces:

AutoCloseable, Runnable

public class MultiQueueTaskRunner
extends Object
implements Runnable, AutoCloseable

Picks up tasks from the work queue, runs them and marks them as completed or failed.

Runs tasks in a pool. The size of this pool is configurable in the properties file. Controls marking the state of running TaskRunner in Zookeeper.

Author:

Denis Lobanov, alexandraorth

Constructor Summary

Constructors

Constructor and Description
MultiQueueTaskRunner(EngineID engineId, TaskStateStorage storage, ZookeeperConnection connection)

Method Summary

Modifier and Type	Method and Description
void	close() Stop the main loop, causing run() to exit.
void	run() Start the main loop, this will block until a call to close() that wakes up the consumer.

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiQueueTaskRunner

public MultiQueueTaskRunner(EngineID engineId,
                            TaskStateStorage storage,
                            ZookeeperConnection connection)

Method Detail

run

public void run()

Start the main loop, this will block until a call to close() that wakes up the consumer. The only way to exit this loop without throwing an exception is by calling consumer.wakeup() We do not want to catch any exceptions here. The caller of this TaskRunner should handle the case where an exception is thrown. It is recommended to register the TaskRunner thread with a UncaughtExceptionHandler. The catch(Throwable t) here is merely for logging purposes. You will notice that the exception is re-thrown.

Specified by:

run in interface Runnable

close

public void close()

Stop the main loop, causing run() to exit. noThrow() functions used here so that if an error occurs during execution of a certain step, the subsequent stops continue to execute.

Specified by:

close in interface AutoCloseable