[YARN-2155] FairScheduler: Incorrect threshold check for preemption

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.5.0
• Hadoop Flags: Reviewed
• Assignee: Wei Yan
• Reporter: Wei Yan
• Created: 12/Jun/14 16:46
• Updated: 15/Aug/14 05:44
• Resolved: 12/Jun/14 21:29

Description

private boolean shouldAttemptPreemption() {
  if (preemptionEnabled) {
    return (preemptionUtilizationThreshold < Math.max(
        (float) rootMetrics.getAvailableMB() / clusterResource.getMemory(),
        (float) rootMetrics.getAvailableVirtualCores() /
            clusterResource.getVirtualCores()));
  }
  return false;
}

preemptionUtilizationThreshould should be compared with allocatedResource instead of availableResource.

Issue Links

• is broken by: YARN-2073 Fair Scheduler: Add a utilization threshold to prevent preempting resources when cluster is free