@VincentSF   oh ok got it...    Go to CM -> Yarn -> Configuration -> search for "yarn.nodemanager.resource.memory-mb"   it will show you the memory restriction that you set for each node (it will get configuration from yarn-site.xml)   You can tweak this 'little'.    Note: 1. The memory is common for all the services. so you cannot use all the memory for Yarn alone. Also don't increase the memroy for the above setting too much because it may create memory overlap issue accross the services. So may be you can set aprox 50% of total memory but again it is depends upon the memory utilization by other services. Since you have 183 nodes, the 50% is not common for all the nodes, it will change case by case   2. Also when you increase your memory on each node, it is not recommended to increase more than  yarn.scheduler.maximum-allocation-mb   Hope this will give some idea   ... View more