+++ /dev/null
-.. This work is licensed under a Creative Commons Attribution 4.0 International License.
-.. http://creativecommons.org/licenses/by/4.0
-
-======================
-Get valid server state
-======================
-
-Related Blueprints:
-===================
-
-https://blueprints.launchpad.net/nova/+spec/get-valid-server-state
-
-Problem description
-===================
-
-Previously when the owner of a VM has queried his VMs, he has not received
-enough state information, states have not changed fast enough in the VIM and
-they have not been accurate in some scenarios. With this change this gap is now
-closed.
-
-A typical case is that, in case of a fault of a host, the user of a high
-availability service running on top of that host, needs to make an immediate
-switch over from the faulty host to an active standby host. Now, if the compute
-host is forced down [1] as a result of that fault, the user has to be notified
-about this state change such that the user can react accordingly. Similarly,
-a change of the host state to "maintenance" should also be notified to the
-users.
-
-What is changed
-===============
-
-A new ``host_status`` parameter is added to the ``/servers/{server_id}`` and
-``/servers/detail`` endpoints in microversion 2.16. By this new parameter
-user can get additional state information about the host.
-
-``host_status`` possible values where next value in list can override the
-previous:
-
-- ``UP`` if nova-compute is up.
-- ``UNKNOWN`` if nova-compute status was not reported by servicegroup driver
- within configured time period. Default is within 60 seconds,
- but can be changed with ``service_down_time`` in nova.conf.
-- ``DOWN`` if nova-compute was forced down.
-- ``MAINTENANCE`` if nova-compute was disabled. MAINTENANCE in API directly
- means nova-compute service is disabled. Different wording is used to avoid
- the impression that the whole host is down, as only scheduling of new VMs
- is disabled.
-- Empty string indicates there is no host for server.
-
-``host_status`` is returned in the response in case the policy permits. By
-default the policy is for admin only in Nova policy.json::
-
- "os_compute_api:servers:show:host_status": "rule:admin_api"
-
-For an NFV use case this has to also be enabled for the owner of the VM::
-
- "os_compute_api:servers:show:host_status": "rule:admin_or_owner"
-
-REST API examples:
-==================
-
-Case where nova-compute is enabled and reporting normally::
-
- GET /v2.1/{tenant_id}/servers/{server_id}
-
- 200 OK
- {
- "server": {
- "host_status": "UP",
- ...
- }
- }
-
-Case where nova-compute is enabled, but not reporting normally::
-
- GET /v2.1/{tenant_id}/servers/{server_id}
-
- 200 OK
- {
- "server": {
- "host_status": "UNKNOWN",
- ...
- }
- }
-
-Case where nova-compute is enabled, but forced_down::
-
- GET /v2.1/{tenant_id}/servers/{server_id}
-
- 200 OK
- {
- "server": {
- "host_status": "DOWN",
- ...
- }
- }
-
-Case where nova-compute is disabled::
-
- GET /v2.1/{tenant_id}/servers/{server_id}
-
- 200 OK
- {
- "server": {
- "host_status": "MAINTENANCE",
- ...
- }
- }
-
-Host Status is also visible in python-novaclient::
-
- +-------+------+--------+------------+-------------+----------+-------------+
- | ID | Name | Status | Task State | Power State | Networks | Host Status |
- +-------+------+--------+------------+-------------+----------+-------------+
- | 9a... | vm1 | ACTIVE | - | RUNNING | xnet=... | UP |
- +-------+------+--------+------------+-------------+----------+-------------+
-
-Links:
-======
-
-[1] Manual for OpenStack NOVA API for marking host down
-http://artifacts.opnfv.org/doctor/docs/manuals/mark-host-down_manual.html
-
-[2] OpenStack compute manual page
-http://developer.openstack.org/api-ref-compute-v2.1.html#compute-v2.1
Code Review / doctor.git / blobdiff