Each application and service that is running on a cluster has specific CPU needs. For example, the global-cluster node assigns CPU shares.
If you want to apply CPU shares, you must specify the Fair Share Scheduler (FFS) as the default scheduler in the cluster. A CPU share is the portion of the system's CPU resources that is allocated to a project. Shares define the relative importance of workloads in relation to other workloads. When you assign CPU shares to a project, your primary concern is not the number of shares the project has. Rather, you should know how many of those other projects will be competing with it for CPU resources.