ai.grakn.engine.postprocessing

Class ResourceDeduplicationTask

java.lang.Object

ai.grakn.engine.postprocessing.ResourceDeduplicationTask

All Implemented Interfaces:

BackgroundTask

public class ResourceDeduplicationTask
extends Object
implements BackgroundTask

This is a task meant to be run periodically to eliminate resource duplication. The task performs a map-reduce job using the GraknComputer where each resource index key, i.e. the resource value+type combination, is mapped to all its corresponding resource instances. The reduction steps, delete superfluous duplicates and forces instances referring to them to point to the unique remaining resource instance for that key.

Author:

borislav

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ResourceDeduplicationTask.Job The map-reduce job submitted to the GraknGraphComputer that scan the whole set of resources in the graph and reduces by eliminating duplicates.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DELETE_UNATTACHED_CONFIG
static boolean	DELETE_UNATTACHED_DEFAULT
static String	KEYSPACE_CONFIG
static String	KEYSPACE_DEFAULT

Constructor Summary

Constructors

Constructor and Description
ResourceDeduplicationTask()

Method Summary

Modifier and Type	Method and Description
void	pause() Called to suspend the execution of a currently running task.
boolean	resume(java.util.function.Consumer<TaskCheckpoint> saveCheckpoint, TaskCheckpoint lastCheckpoint) This method may be called when resuming from a paused state or recovering from a crash or failure of any kind.
boolean	start(java.util.function.Consumer<TaskCheckpoint> saveCheckpoin, mjson.Json configuration) Called to start execution of the task, may be called on a newly scheduled or previously stopped task.
boolean	stop() Called to stop execution of the task, may be called on a running or paused task.
Long	totalElimintated()

Methods inherited from class java.lang.Object

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

Field Detail

KEYSPACE_CONFIG

public static final String KEYSPACE_CONFIG

See Also:

Constant Field Values

KEYSPACE_DEFAULT

public static final String KEYSPACE_DEFAULT

See Also:

Constant Field Values

DELETE_UNATTACHED_CONFIG

public static final String DELETE_UNATTACHED_CONFIG

See Also:

Constant Field Values

DELETE_UNATTACHED_DEFAULT

public static final boolean DELETE_UNATTACHED_DEFAULT

See Also:

Constant Field Values

Constructor Detail

ResourceDeduplicationTask

public ResourceDeduplicationTask()

Method Detail

start

public boolean start(java.util.function.Consumer<TaskCheckpoint> saveCheckpoin,
                     mjson.Json configuration)

Description copied from interface: BackgroundTask

Called to start execution of the task, may be called on a newly scheduled or previously stopped task.

Specified by:

start in interface BackgroundTask

Parameters:

saveCheckpoin - Consumer which can be called at any time to save a state checkpoint that would allow the task to resume from this point should it crash.

Returns:

true if the task successfully completed, or false if it was stopped.

resume

public boolean resume(java.util.function.Consumer<TaskCheckpoint> saveCheckpoint,
                      TaskCheckpoint lastCheckpoint)

Description copied from interface: BackgroundTask

This method may be called when resuming from a paused state or recovering from a crash or failure of any kind.

Specified by:

resume in interface BackgroundTask

Parameters:

saveCheckpoint - Consumer which can be called at any time to save a state checkpoint that would allow the task to resume from this point should it crash.

lastCheckpoint - The last checkpoint as sent to saveCheckpoint.

stop

public boolean stop()

Description copied from interface: BackgroundTask

Called to stop execution of the task, may be called on a running or paused task. Task should stop gracefully.

Specified by:

stop in interface BackgroundTask

Returns:

true if the task was successfully stopped, or false if it could not be stopped. TODO: Should we allow start() to be called after stop()?

pause

public void pause()

Description copied from interface: BackgroundTask

Called to suspend the execution of a currently running task. The object may be destroyed after this call. TODO: stop running

Specified by:

pause in interface BackgroundTask

totalElimintated

public Long totalElimintated()