The basic strategy requires the following metrics:
metric | service name | plugins | comment |
---|---|---|---|
compute.node.cpu.percent |
ceilometer | none | |
cpu_util |
ceilometer | none |
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.
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.
change_nova_service_state
Disables or enables the nova-compute service, deployed on a host
By using this action, you will be able to update the state of a nova-compute service. A disabled nova-compute service can not be selected by the nova scheduler for future deployment of server.
The action schema is:
schema = Schema({ 'resource_id': str, 'state': str, 'disabled_reason': str, })The resource_id references a nova-compute service name (list of available nova-compute services is returned by this command:
nova service-list --binary nova-compute
). The state value should either be ONLINE or OFFLINE. The disabled_reason references the reason why Watcher disables this nova-compute service. The value should be with watcher_ prefix, such as watcher_disabled, watcher_maintaining.
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.
Strategy parameter is:
parameter | type | default Value | description |
---|---|---|---|
migration_attempts |
Number | 0 | Maximum number of combinations to be tried by the strategy while searching for potential candidates. To remove the limit, set it to 0 |
period |
Number | 7200 | The time interval in seconds for getting statistic aggregation from metric data source |
[{'value': 0, 'name': 'released_nodes_ratio', 'unit': '%', 'description': u'Ratio of released compute nodes divided by the total number of enabled compute nodes.'}]
$ openstack optimize audittemplate create \
at1 server_consolidation --strategy basic
$ openstack optimize audit create -a at1 -p migration_attempts=4
None.
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