yarn is not honouring yarn.nodemanager.resource.cpu-vcores
YARN is running more containers than allocated cores because by default DefaultResourceCalculator is used. It considers only memory.
public int computeAvailableContainers(Resource available, Resource required) {// Only consider memoryreturn available.getMemory() / required.getMemory(); }Use DominantResourceCalculator, It uses both cpu and memory.
Set below config in capacity-scheduler.xml
yarn.scheduler.capacity.resource-calculator=org.apache.hadoop.yarn.util.resource.DominantResourceCalculatorMore about DominantResourceCalculator