本节介绍通过UI， 命令行， 配置文件， YARN API 管理YARN资源：
- Ambari UI
- ResourceManager UI
- Command line and manual configuration
- YARN API
The Configs tab provides the ability to modify the default behavior of YARN and YARN applications. The default Settings sub-tab contains several customizeable settings that can be configured via a GUI. These include:
Memory: Controls the amount of node memory that can be allocated for containers, as well as the minimum and maximum size of those containers.
YARN Features: Enable Node Lables to restrict YARN applications so that they can only run on nodes that have a specified label. Pre-emption allows the specification of higher-priority applications, which can reclaim resources from lower-priority applications in the event of resource contention.
CPU: Enable CPU scheduling, which changes the default scheduler behavior to include both memory *and* CPU (rather than just memory) when making scheduling decisions. Enable CPU Isolation, which allows the isolation of CPU-heavy processes. When applicable (more on that in a later lesson), this section also controls the percentage of physical CPU allocated for containers on a node, the number of virtual cores allocated for containers. The Container settings set the minimum and maximum number of virtual cores (VCores) that can be allocated to any individual container.
