Package hudson.model

Class LoadBalancer

java.lang.Object
hudson.model.LoadBalancer
All Implemented Interfaces:
ExtensionPoint
public abstract class LoadBalancer extends Object implements ExtensionPoint
Strategy that decides which Queue.Task gets run on which Executor.

Even though this is marked as ExtensionPoint, you do not register your implementation with @Extension. Instead, call Queue.setLoadBalancer(LoadBalancer) to install your implementation.

Since:
1.301
Author:
Kohsuke Kawaguchi

  • Field Details

    • CONSISTENT_HASH

      public static final LoadBalancer CONSISTENT_HASH
      Uses a consistent hash for scheduling.

    • DEFAULT

      @Deprecated 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 Details

    • LoadBalancer

      public LoadBalancer()

  • Method Details

    • map

      @CheckForNull public abstract MappingWorksheet.Mapping map(@NonNull 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.