Examine Jobs Queue by Queue

Specify whether all jobs that can be run from the highest-priority queue are run.

Important: The Schedule By Queue parameter can only be updated if the cluster was added by a user with passwordless sudo permissions and therefore may not appear as a Scheduling parameter.

When a scheduler examines waiting jobs, it can either consider all of the jobs in its partition(s) as a whole, or it can consider jobs queue by queue. When considering jobs queue by queue, a scheduler runs all the jobs it can from the first queue before examining the jobs in the next queue, and so on. This behavior is controlled by the Schedule By Queue parameter.

When the Schedule By Queue parameter is enabled, jobs in the highest-priority queue are evaluated as a group, then jobs in the next-highest priority queue are evaluated. In this case, PBS runs all the jobs it can from each queue before moving to the next queue, with the following exception: if there are jobs in the Reservation, Express, Preempted, or Starving job execution classes, those are considered before any queue.

The Schedule By Queue parameter applies to all of the queues in a scheduler’s partition(s). This means that either all jobs are scheduled as if they are in one large queue, or jobs are scheduled queue by queue.

All queues are always sorted by queue priority. A queue with a higher value is examined before a queue with a lower value. If you do not assign priorities to queues, their ordering is undefined.

The Schedule By Queue parameter is a primetime option, meaning that you can configure it separately for primetime and non-primetime, or you can specify it for all of the time.
Note: This parameter is overridden by the Round-Robin Scheduling parameter when it is enabled.
  1. Click the Configure tab.
  2. Choose the HPC to configure.

    Choose an HPC
    Figure 1. Choose an HPC
  3. Click Scheduling from the PBS Professional menu located on the left-hand side of the web page.
  4. Scroll down to the second list of Scheduling parameters.
  5. Click located to the right of Schedule by Queue.
  6. Choose one of the following options to examine jobs queue by queue:
    • To examine jobs queue by queue for both prime and non-prime time, enable Schedule By Queue and enable both Prime and Non-Prime.
    • To examine jobs queue by queue for only prime time, enable Schedule By Queue, enable Prime and disable Non-Prime.
    • To examine jobs queue by queue for only non-prime time, enable Schedule By Queue, enable Non-Prime and disable Prime.
    • To specify that all jobs are treated as if they are in one large queue, disable Schedule By Queue.
  7. Click to save the changes.