ai.grakn.engine.backgroundtasks

Interface TaskManager

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

DistributedTaskManager, StandaloneTaskManager

public interface TaskManager
extends AutoCloseable

The base TaskManager interface.

Provides common methods for scheduling tasks for execution and stopping task execution.

Author:

Denis Lobanov, alexandraorth

Method Summary

Modifier and Type	Method and Description
String	createTask(String taskClassName, String createdBy, java.time.Instant runAt, long period, mjson.Json configuration) Schedule a single shot/one off BackgroundTask to run after a @delay in milliseconds.
TaskManager	stopTask(String id, String requesterName) Stop a Scheduled, Paused or Running task.
TaskStateStorage	storage() Return the StateStorage instance that is used by this class.

Methods inherited from interface java.lang.AutoCloseable

close

Method Detail

createTask

String createTask(String taskClassName,
                  String createdBy,
                  java.time.Instant runAt,
                  long period,
                  mjson.Json configuration)

Schedule a single shot/one off BackgroundTask to run after a @delay in milliseconds. All parameters must not be null unless stated otherwise.

Parameters:

taskClassName - Name of the class implementing the BackgroundTask interface that is to be scheduled for later execution.

runAt - Instant when task should run.

period - A non-zero value indicates that this should be a recurring task and period indicates the delay between subsequent runs of the task after successful execution.

configuration - A JSONObject instance containing configuration and optionally data for the task. This is an optional parameter and may be set to null to not pass any configuration (task.start() will get an initialised but empty JSONObject).

Returns:

Assigned ID of task scheduled for later execution.

stopTask

TaskManager stopTask(String id,
                     String requesterName)

Stop a Scheduled, Paused or Running task. Task's .stop() method will be called to perform any cleanup and the task is killed afterwards.

Parameters:

id - String of task to stop.

requesterName - Optional String to denote who requested this call; used for status reporting and may be null.

Returns:

Instance of the class implementing TaskManager.

storage

TaskStateStorage storage()

Return the StateStorage instance that is used by this class.

Returns:

A StateStorage instance.