hudson.model.queue
Class MappingWorksheet

java.lang.Object
  hudson.model.queue.MappingWorksheet

public class MappingWorksheet
extends Object

Defines a mapping problem for answering "where do we execute this task?"

The heart of the placement problem is a mapping problem. We are given a Queue.Task, (which in the general case consists of a set of SubTasks), and we are also given a number of idle Executors, and our goal is to find a mapping from the former to the latter, which determines where each SubTask gets executed.

This mapping is done under two constraints:

• "Same node" constraint. Some of the subtasks need to be co-located on the same node. See SubTask.getSameNodeConstraint()
• Label constraint. SubTasks can specify that it can be only run on nodes that has the label.

We first fold the former constraint into the problem definition. That is, we now consider a set of SubTasks that need to be co-located as a single MappingWorksheet.WorkChunk. Similarly, we consider a set of all Executors from the same node as MappingWorksheet.ExecutorChunk. Now, the problem becomes the weighted matching problem from MappingWorksheet.WorkChunk to MappingWorksheet.ExecutorChunk.

An instance of MappingWorksheet captures a problem definition, plus which MappingWorksheet.ExecutorChunk and MappingWorksheet.WorkChunk are compatible. The purpose of this class (and MappingWorksheet.ExecutorChunk and MappingWorksheet.WorkChunk) are to expose a lot of convenience methods to assist various algorithms that produce the solution of this mapping problem, which is represented as MappingWorksheet.Mapping.

Author:

Kohsuke Kawaguchi

See Also:

LoadBalancer#map(Task, MappingWorksheet)

Nested Class Summary

class	MappingWorksheet.ExecutorChunk
static class	MappingWorksheet.ExecutorSlot
class	MappingWorksheet.Mapping Represents the solution to the mapping problem.
class	MappingWorksheet.WorkChunk

Field Summary

List<MappingWorksheet.ExecutorChunk>	executors
Queue.BuildableItem	item Queue.BuildableItem for which we are trying to figure out the execution plan.
List<MappingWorksheet.WorkChunk>	works

Constructor Summary

MappingWorksheet(Queue.BuildableItem item, List<? extends MappingWorksheet.ExecutorSlot> offers)

MappingWorksheet(Queue.BuildableItem item, List<? extends MappingWorksheet.ExecutorSlot> offers, Collection<? extends LoadPredictor> loadPredictors)

Method Summary

MappingWorksheet.ExecutorChunk	executors(int index)
MappingWorksheet.WorkChunk	works(int index)

Methods inherited from class java.lang.Object

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

Field Detail

executors

public final List<MappingWorksheet.ExecutorChunk> executors

works

public final List<MappingWorksheet.WorkChunk> works

item

public final Queue.BuildableItem item

Queue.BuildableItem for which we are trying to figure out the execution plan. Never null.

Constructor Detail

MappingWorksheet

public MappingWorksheet(Queue.BuildableItem item,
                        List<? extends MappingWorksheet.ExecutorSlot> offers)

MappingWorksheet

public MappingWorksheet(Queue.BuildableItem item,
                        List<? extends MappingWorksheet.ExecutorSlot> offers,
                        Collection<? extends LoadPredictor> loadPredictors)

Method Detail

works

public MappingWorksheet.WorkChunk works(int index)

executors

public MappingWorksheet.ExecutorChunk executors(int index)