OpenStack Watcher provides a flexible and scalable resource optimization service for multi-tenant OpenStack-based clouds. To add the service, one charm is needed:

This charm provides the Watcher API, Decision Engine, and Applier.


Watcher is supported by Charmed OpenStack starting with OpenStack 2023.2 (Bobcat) on Ubuntu 22.04 LTS (Jammy).


The below overlay bundle encapsulates what is needed in terms of the deployment.


An overlay’s parameters should be adjusted as per the local environment. In particular, the following placeholders must be replaced with actual values:




Replace $SERIES with the Ubuntu release running on the cloud nodes (e.g. ‘jammy’). For channel information see the Charm delivery page.

series: $SERIES


- - watcher:shared-db
  - watcher-mysql-router:shared-db
- - watcher-mysql-router:db-router
  - mysql-innodb-cluster:db-router
- - keystone:identity-service
  - watcher:identity-service
- - rabbitmq-server:amqp
  - watcher:amqp


    charm: ch:mysql-router
    channel: $CHANNEL_MYSQL

    charm: ch:watcher
    num_units: 1
      debug: True
      datasources: gnocchi
      planner: weight
      planner-config: >
            "weights": "change_node_power_state:9,change_nova_service_state:50,migrate:30,nop:70,resize:20,sleep:40,turn_host_to_acpi_s3_state:10,volume_migrate:60",
            "parallelization": "change_node_power_state:2,change_nova_service_state:1,migrate:2,nop:1,resize:2,sleep:1,turn_host_to_acpi_s3_state:2,volume_migrate:2"

The feature should be deployable during (or after) the deployment of a cloud - as per the Juju documentation: How to add an overlay bundle.


This example configuration demonstrates how to apply an optimisation strategy towards the goal of reducing energy consumption. It does this by consolidating VMs on the least number of hypervisors.

Create an audit template:

openstack optimize audittemplate create at1 \
   --stategy vm_workload_consolidation \
   --goal server_consolidation

Create an audit:

openstack optimize audit create \
   --name audit1
   --audit-template at1 \
   --audit-type oneshot \
   --parameter period=600 \
   --parameter granularity=300

Check the action plan:

openstack optimize actionplan show audit1

Check the actions associated to the plan:

openstack optimize action list --audit audit1

For more details on the available strategies and their different options see Strategies in the Watcher documentation.