| --- |
| title: Policies |
| partial-summary-depth: 1 |
| layout: website-normal |
| children: |
| - available_policies.md |
| - writing_policies.md |
| --- |
| |
| Policies perform the active management enabled by Brooklyn. |
| They can subscribe to entity sensors and be triggered by them (or they can run periodically, |
| or be triggered by external systems). |
| |
| Policies can add subscriptions to sensors on any entity. Normally a policy will subscribe to sensors on |
| either its associated entity, that entity's children and/or to the members of a "group" entity. |
| |
| Common uses of a policy include the following: |
| |
| * perform calculations, |
| * look up other values, |
| * invoke effectors (management policies) or, |
| * cause the entity associated with the policy to emit sensor values (enricher policies). |
| |
| Entities can have zero or more `Policy` instances attached to them. |
| |
| {% include list-children.html %} |
| |
