[YARN-10397] SchedulerRequest should be forwarded to scheduler if custom scheduler supports placement constraints

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.4.0, 3.3.1
• Fix Version/s: 3.4.0, 3.3.1
• Component/s: capacity scheduler
• Target Version/s: 3.4.0, 3.3.1
• Hadoop Flags: Reviewed
• Assignee: Bilwa S T
• Reporter: Bilwa S T
• Created: 12/Aug/20 19:04
• Updated: 11/Feb/24 13:02
• Resolved: 09/Sep/20 11:42

Description

Currently only CapacityScheduler supports placement constraints so request gets forwarded only for capacityScheduler. Below exception will be thrown if custom scheduler supports placement constraint

if (request.getSchedulingRequests() != null
        && !request.getSchedulingRequests().isEmpty()) {
      if (!(scheduler instanceof CapacityScheduler)) {
        String message = "Found non empty SchedulingRequest of "
            + "AllocateRequest for application=" + appAttemptId.toString()
            + ", however the configured scheduler="
            + scheduler.getClass().getCanonicalName()
            + " cannot handle placement constraints, rejecting this "
            + "allocate operation";
        LOG.warn(message);
        throw new YarnException(message);
      }
    }