相关blueprints：
https://blueprints.launchpad.net/nova/ spec/mark-host-down https://blueprints.launchpad.net/python-novaclient/ spec/support-force-down-service
为何要新增该API
有了该API，可以让外部故障监控获得nova-compute服务down的速度更快，这将直接提高VM HA的故障恢复时间（从故障节点疏散VM到正常节点的时间）。
REST API for forced down
request: PUT /v2.1/{tenant_id}/os-services/force-down { “binary”: “nova-compute”, “host”: “compute1”, “forced_down”: true }
response: 200 OK { “service”: { “host”: “compute1”, “binary”: “nova-compute”, “forced_down”: true } }
Example: curl -g -i -X PUT http://{service_host_ip}:8774/v2.1/{tenant_id}/os-services /force-down -H “Content-Type: application/json” -H “Accept: application/json ” -H “X-OpenStack-Nova-API-Version: 2.11” -H “X-Auth-Token: {token}” -d ‘{“b inary”: “nova-compute”, “host”: “compute1”, “forced_down”: true}’
CLI for forced down
nova service-force-down nova-compute
Example: nova service-force-down compute1 nova-compute
REST API for disabling forced down
request: PUT /v2.1/{tenant_id}/os-services/force-down { “binary”: “nova-compute”, “host”: “compute1”, “forced_down”: false }
response: 200 OK { “service”: { “host”: “compute1”, “binary”: “nova-compute”, “forced_down”: false } }
Example: curl -g -i -X PUT http://{service_host_ip}:8774/v2.1/{tenant_id}/os-services /force-down -H “Content-Type: application/json” -H “Accept: application/json ” -H “X-OpenStack-Nova-API-Version: 2.11” -H “X-Auth-Token: {token}” -d ‘{“b inary”: “nova-compute”, “host”: “compute1”, “forced_down”: false}’
CLI for disabling forced down
nova service-force-down –unset nova-compute
Example: nova service-force-down –unset compute1 nova-compute
