io.druid.indexing.common.task

Class MergeTaskBase

java.lang.Object

io.druid.indexing.common.task.AbstractTask

io.druid.indexing.common.task.AbstractFixedIntervalTask

io.druid.indexing.common.task.MergeTaskBase

All Implemented Interfaces:

Task

Direct Known Subclasses:

AppendTask, MergeTask

public abstract class MergeTaskBase
extends AbstractFixedIntervalTask

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	MergeTaskBase(String id, String dataSource, List<DataSegment> segments, SegmentWriteOutMediumFactory segmentWriteOutMediumFactory, Map<String,Object> context)

Method Summary

Modifier and Type	Method and Description
int	getPriority() Returns task priority.
List<DataSegment>	getSegments()
SegmentWriteOutMediumFactory	getSegmentWriteOutMediumFactory()
boolean	isReady(TaskActionClient taskActionClient) Checks pre-existing segments in "context" to confirm that this merge query is valid.
protected abstract File	merge(TaskToolbox taskToolbox, Map<DataSegment,File> segments, File outDir)
TaskStatus	run(TaskToolbox toolbox) Execute a task.
String	toString()
protected void	verifyInputSegments(List<DataSegment> segments)

Methods inherited from class io.druid.indexing.common.task.AbstractFixedIntervalTask

getInterval

Methods inherited from class io.druid.indexing.common.task.AbstractTask

canRestore, equals, getClasspathPrefix, getContext, getDataSource, getGroupId, getId, getNodeType, getQueryRunner, getTaskResource, hashCode, stopGracefully, success

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface io.druid.indexing.common.task.Task

getContextValue, getContextValue, getType

Constructor Detail

MergeTaskBase

protected MergeTaskBase(String id,
                        String dataSource,
                        List<DataSegment> segments,
                        @Nullable
                        SegmentWriteOutMediumFactory segmentWriteOutMediumFactory,
                        Map<String,Object> context)

Method Detail

verifyInputSegments

protected void verifyInputSegments(List<DataSegment> segments)

getPriority

public int getPriority()

Description copied from interface: Task

Returns task priority. The task priority is currently used only for prioritized locking, but, in the future, it can be used for task scheduling, cluster resource management, etc.

Returns:

task priority

See Also:

for default task priorities

run

public TaskStatus run(TaskToolbox toolbox)
               throws Exception

Description copied from interface: Task

Execute a task. This typically runs on a worker as determined by a TaskRunner, and will be run while holding a lock on our dataSource and implicit lock interval (if any). If this method throws an exception, the task should be considered a failure.

Parameters:

toolbox - Toolbox for this task

Returns:

Some kind of finished status (isRunnable must be false).

Throws:

Exception - if this task failed

isReady

public boolean isReady(TaskActionClient taskActionClient)
                throws Exception

Checks pre-existing segments in "context" to confirm that this merge query is valid. Specifically, confirm that we are operating on every segment that overlaps the chosen interval.

Specified by:

isReady in interface Task

Overrides:

isReady in class AbstractFixedIntervalTask

Parameters:

taskActionClient - action client for this task (not the full toolbox)

Returns:

true if ready, false if not ready yet

Throws:

Exception - if the task should be considered a failure

merge

protected abstract File merge(TaskToolbox taskToolbox,
                              Map<DataSegment,File> segments,
                              File outDir)
                       throws Exception

Throws:

Exception

getSegments

public List<DataSegment> getSegments()

getSegmentWriteOutMediumFactory

@Nullable
public SegmentWriteOutMediumFactory getSegmentWriteOutMediumFactory()

toString

public String toString()

Overrides:

toString in class AbstractTask