[YARN-2145] FairScheduler can assign more resources to queue with MaxShare set.

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 2.5.0
• Component/s: fairscheduler
• Target Version/s: 2.5.0
• Assignee: Unassigned
• Reporter: Andrey Stepachev
• Created: 11/Jun/14 12:39
• Updated: 11/Jun/14 14:31
• Resolved: 11/Jun/14 14:31

Description

method fair.FSQueue#assignContainerPreCheck() uses Resources.fitsIn incorrectly, because if queue is at its maximum capacity method returns true and container can be assigned to queue with maximum resources already consumed.
That is because fitsIn code do '<=' comparison and if allocated resources == max resources fitsIn still returns true, and consequently pre check successes

  public static boolean fitsIn(Resource smaller, Resource bigger) {
    return smaller.getMemory() <= bigger.getMemory() &&
        smaller.getVirtualCores() <= bigger.getVirtualCores();
  }

Provided patch introduced Resources.less method, it more lightweight then lessThan.

Issue Links

• duplicates: YARN-2083 In fair scheduler, Queue should not been assigned more containers when its usedResource had reach the maxResource limit