Workload Balance Migration Strategy

Workload Balance Migration Strategy

Synopsis

display name: Workload Balance Migration Strategy

goal: workload_balancing

Requirements

None.

Metrics

The workload_balance strategy requires the following metrics:

metric service name plugins comment
cpu_util ceilometer none  
memory.resident ceilometer none  

Cluster data model

Default Watcher’s Compute cluster data model:

Nova cluster data model collector

The Nova cluster data model collector creates an in-memory representation of the resources exposed by the compute service.

Actions

Default Watcher’s actions:

action description
migration

Migrates a server to a destination nova-compute host

This action will allow you to migrate a server to another compute destination host. Migration type ‘live’ can only be used for migrating active VMs. Migration type ‘cold’ can be used for migrating non-active VMs as well active VMs, which will be shut down while migrating.

The action schema is:

schema = Schema({
 'resource_id': str,  # should be a UUID
 'migration_type': str,  # choices -> "live", "cold"
 'destination_node': str,
 'source_node': str,
})

The resource_id is the UUID of the server to migrate. The source_node and destination_node parameters are respectively the source and the destination compute hostname (list of available compute hosts is returned by this command: nova service-list --binary nova-compute).

Note

Nova API version must be 2.56 or above if destination_node parameter is given.

Planner

Default Watcher’s planner:

Weight planner implementation

This implementation builds actions with parents in accordance with weights. Set of actions having a higher weight will be scheduled before the other ones. There are two config options to configure: action_weights and parallelization.

Limitations

  • This planner requires to have action_weights and parallelization configs tuned well.

Configuration

Strategy parameters are:

parameter type default Value description
metrics String ‘cpu_util’ Workload balance base on cpu or ram utilization. choice: [‘cpu_util’, ‘memory.resident’]
threshold Number 25.0 Workload threshold for migration
period Number 300 Aggregate time period of ceilometer

Efficacy Indicator

None

Algorithm

For more information on the Workload Balance Migration Strategy please refer to: https://specs.openstack.org/openstack/watcher-specs/specs/mitaka/implemented/workload-balance-migration-strategy.html

How to use it ?

$ openstack optimize audittemplate create \
  at1 workload_balancing --strategy workload_balance

$ openstack optimize audit create -a at1 -p threshold=26.0 \
        -p period=310 -p metrics=cpu_util
Creative Commons Attribution 3.0 License

Except where otherwise noted, this document is licensed under Creative Commons Attribution 3.0 License. See all OpenStack Legal Documents.