Defining service policies

A service policy is a named collection of service class and resource group specification overrides. When a policy is put into effect, the overrides are merged with the service class and resource group specifications in the service definition. A policy override is a way to change a goal or resource group capacity without having to redefine all of your service classes and resource groups.

See Summary of service definition and service policy concepts for an overview of the relationship between a service definition and a service policy, and Figure 1 for a visual overview of how service policy overrides work. Note that in an ideal scenario, you would only have to define your service definition once. As part of that service definition, you would predefine multiple policies to meet varying performance goals or business needs. Once the service definition is installed, you would then activate one policy at a time, and then, when appropriate, switch to another. Note that you must define at least one service policy, and you can define up to 99.

When you are creating your service definition, you may choose to define one empty “default” policy with no overrides at all. Next, create your workloads and service classes. Then determine how and when your service classes may have different goals at different times. Define additional policies with the appropriate overrides for these time periods.