hudson.model
Class LoadBalancer

java.lang.Object
  hudson.model.LoadBalancer

public abstract class LoadBalancer
extends Object

Strategy that decides which Queue.Task gets run on which Executor.

Since:

1.301

Author:

Kohsuke Kawaguchi

Field Summary

static LoadBalancer	CONSISTENT_HASH Uses a consistent hash for scheduling.
static LoadBalancer	DEFAULT Deprecated. as of 1.377 The only implementation in the core now is the one based on consistent hash.

Constructor Summary

LoadBalancer()

Method Summary

abstract MappingWorksheet.Mapping	map(Queue.Task task, MappingWorksheet worksheet) Chooses the executor(s) to carry out the build for the given task.
protected LoadBalancer	sanitize() Wraps this LoadBalancer into a decorator that tests the basic sanity of the implementation.

Methods inherited from class java.lang.Object

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

Field Detail

CONSISTENT_HASH

public static final LoadBalancer CONSISTENT_HASH

Uses a consistent hash for scheduling.

DEFAULT

public static final LoadBalancer DEFAULT

Deprecated. as of 1.377 The only implementation in the core now is the one based on consistent hash.

Traditional implementation of this.

Constructor Detail

LoadBalancer

public LoadBalancer()

Method Detail

map

public abstract MappingWorksheet.Mapping map(Queue.Task task,
                                             MappingWorksheet worksheet)

Chooses the executor(s) to carry out the build for the given task.

This method is invoked from different threads, but the execution is serialized by the caller. The thread that invokes this method always holds a lock to Queue, so queue contents can be safely introspected from this method, if that information is necessary to make decisions.

Parameters:

task - The task whose execution is being considered. Never null.

worksheet - The work sheet that represents the matching that needs to be made. The job of this method is to determine which work units on this worksheet are executed on which executors (also on this worksheet.)

Returns:

Build up the mapping by using the given worksheet and return it. Return null if you don't want the task to be executed right now, in which case this method will be called some time later with the same task.

sanitize

protected LoadBalancer sanitize()

Wraps this LoadBalancer into a decorator that tests the basic sanity of the implementation. Only override this if you find some of the checks excessive, but beware that it's like driving without a seat belt.