Symphony resources are shared as defined in the resource distribution plan.
A client makes a request of the session manager, which requests a certain number (n) slots of the resource manager. Based on the values specified in the resource distribution plan, the resource manager returns the number of available slots (m) and the names of the hosts on which the slots reside.
Resources are distributed based on the relationships and values specified in the resource distribution plan.
A policy is a set of rules that defines a behavior for scheduling or resource distribution.
The resource distribution plan is a collection of distribution policies that describes how EGO supplies resources to satisfy the workload demand.
Resource distribution policies define how many resources each application may use, whether the consumer has sole ownership of the resources, or shares them with other consumers. If resources are shared, resource distribution policies define how they are shared, who they are shared with, and when. The resource distribution policies also define how resources are reclaimed when lent, and how they are disbursed when there is contention for the resources.
Defines guaranteed access to a set number of resources. The consumer receives the guaranteed number of resources regardless of its outstanding demand.
Consumers receive resources based on their share ratio (a ratio defining a relative portion of the resources), up to a maximum value, their deserved value.
Any free resources remaining in the shared pool are distributed among consumers based on their share ratio. Share ratio allows more important sibling consumers to borrow more resources than less important siblings.
Defines a relationship between consumers such that unused resources belonging to a consumer may be lent to a sibling consumer. The policy defines limits on the borrowing: a policy may limit borrowing to specific consumers, and limits may be applied to the number of resources that a consumer may borrow. Borrowing order is configurable, to allow borrowers with the highest rank to be processed first.
Defines the criteria under which the lender reclaims its owned resources from borrowers. The policy can specify to allow a grace period before initiating the resource reclaim, or the policy can specify to kill any running workload and reclaim the resources immediately.
Rank applies to the order in which other policies are applied to consumers. Rank determines the order in which the distribution of resources is processed—the highest ranking consumer receives its resources first, borrows resources first, and returns borrowed resources last.