Examples of org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.Schedulable

org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.Schedulable

A Schedulable represents an entity that can launch tasks, such as a job or a queue. It provides a common interface so that algorithms such as fair sharing can be applied both within a queue and across queues. There are currently two types of Schedulables: JobSchedulables, which represent a single job, and QueueSchedulables, which allocate among jobs in their queue. Separate sets of Schedulables are used for maps and reduces. Each queue has both a mapSchedulable and a reduceSchedulable, and so does each job. A Schedulable is responsible for three roles: 1) It can launch tasks through assignTask(). 2) It provides information about the job/queue to the scheduler, including: - Demand (maximum number of tasks required) - Number of currently running tasks - Minimum share (for queues) - Job/queue weight (for fair sharing) - Start time and priority (for FIFO) 3) It can be assigned a fair share, for use with fair scheduling. Schedulable also contains two methods for performing scheduling computations: - updateDemand() is called periodically to compute the demand of the various jobs and queues, which may be expensive (e.g. jobs must iterate through all their tasks to count failed tasks, tasks that can be speculated, etc). - redistributeShare() is called after demands are updated and a Schedulable's fair share has been set by its parent to let it distribute its share among the other Schedulables within it (e.g. for queues that want to perform fair sharing among their jobs).

      Resource totalResources) {
    if (schedulables.isEmpty()) {
      return;
    }


    Schedulable earliest = null;
    for (Schedulable schedulable : schedulables) {
      if (earliest == null ||
          schedulable.getStartTime() < earliest.getStartTime()) {
        earliest = schedulable;
      }
    }
    earliest.setFairShare(Resources.clone(totalResources));
  }

  }


  @Override
  public void computeShares(Collection<? extends Schedulable> schedulables,
      Resource totalResources) {
    Schedulable earliest = null;
    for (Schedulable schedulable : schedulables) {
      if (earliest == null ||
          schedulable.getStartTime() < earliest.getStartTime()) {
        earliest = schedulable;
      }
    }
    earliest.setFairShare(Resources.clone(totalResources));
  }

      Resource totalResources) {
    if (schedulables.isEmpty()) {
      return;
    }


    Schedulable earliest = null;
    for (Schedulable schedulable : schedulables) {
      if (earliest == null ||
          schedulable.getStartTime() < earliest.getStartTime()) {
        earliest = schedulable;
      }
    }
    earliest.setFairShare(Resources.clone(totalResources));
  }

Examples of org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.Schedulable

Related Classes of org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.Schedulable