Resources are distributed in the cluster as defined in the resource distribution plan. The resource distribution plan may implement one or more resource sharing models.
The siloed model guarantees resource availability to all consumers. It is strictly a 'siloed' ownership model: consumers do not share resources, nor are the cluster resources pooled. Each application brings its designated resources to the cluster, and continues to use them exclusively.
In the above example, in a cluster with 1000 slots available, application A has exclusive use of 150 CPU slots, and application B has exclusive use of 850 slots.
The directed share model is based on the siloed model: consumers own a specified number of resources, and are still guaranteed that number when they have demand. The directed share model allows a consumer to lend its unused resources to sibling consumers when their demand exceeds their owned slots.
In the above example, applications A and B each own 500 slots. If application A is not using all of its slots, and application B has a requirement for more than its owned slots, application B can borrow a limited number of slots from application A.
The brokered share or utility model is based entirely on sharing of the cluster resources. Each consumer is assigned a proportional quantity of the slots in the cluster. The proportion is specified as a ratio.
In the above example, application A is guaranteed two of every five slots, and application B is guaranteed three. Slots are only allocated when the demand exists. If application A has no demand, application B may use all slots until application A requires some.