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authorGerald Kunzmann <kunzmann@docomolab-euro.com>2017-02-14 15:38:29 +0000
committerGerald Kunzmann <kunzmann@docomolab-euro.com>2017-02-16 14:41:46 +0000
commitd0b22e1d856cf8f78e152dfb6c150e001e03dd52 (patch)
tree0c3b7af828967d5014c2272675560410fceb6e4d /docs/development/manuals
parente171b396ce87322f2dc5ef0719419144774e43d7 (diff)
Update docs structure according to new guidelines in https://wiki.opnfv.org/display/DOC
Change-Id: I1c8c20cf85aa46269c5bc369f17ab0020862ddc5 Signed-off-by: Gerald Kunzmann <kunzmann@docomolab-euro.com>
Diffstat (limited to 'docs/development/manuals')
-rw-r--r--docs/development/manuals/get-valid-server-state.rst125
-rw-r--r--docs/development/manuals/index.rst13
-rw-r--r--docs/development/manuals/mark-host-down_manual.rst122
3 files changed, 260 insertions, 0 deletions
diff --git a/docs/development/manuals/get-valid-server-state.rst b/docs/development/manuals/get-valid-server-state.rst
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+.. 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
diff --git a/docs/development/manuals/index.rst b/docs/development/manuals/index.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+*******
+Manuals
+*******
+
+.. toctree::
+ :numbered:
+ :maxdepth: 2
+
+.. include:: mark-host-down_manual.rst
+.. include:: get-valid-server-state.rst
diff --git a/docs/development/manuals/mark-host-down_manual.rst b/docs/development/manuals/mark-host-down_manual.rst
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+.. This work is licensed under a Creative Commons Attribution 4.0 International License.
+.. http://creativecommons.org/licenses/by/4.0
+
+=========================================
+OpenStack NOVA API for marking host down.
+=========================================
+
+Related Blueprints:
+===================
+
+ https://blueprints.launchpad.net/nova/+spec/mark-host-down
+ https://blueprints.launchpad.net/python-novaclient/+spec/support-force-down-service
+
+What the API is for
+===================
+
+ This API will give external fault monitoring system a possibility of telling
+ OpenStack Nova fast that compute host is down. This will immediately enable
+ calling of evacuation of any VM on host and further enabling faster HA
+ actions.
+
+What this API does
+==================
+
+ In OpenStack the nova-compute service state can represent the compute host
+ state and this new API is used to force this service down. It is assumed
+ that the one calling this API has made sure the host is also fenced or
+ powered down. This is important, so there is no chance same VM instance will
+ appear twice in case evacuated to new compute host. When host is recovered
+ by any means, the external system is responsible of calling the API again to
+ disable forced_down flag and let the host nova-compute service report again
+ host being up. If network fenced host come up again it should not boot VMs
+ it had if figuring out they are evacuated to other compute host. The
+ decision of deleting or booting VMs there used to be on host should be
+ enhanced later to be more reliable by Nova blueprint:
+ https://blueprints.launchpad.net/nova/+spec/robustify-evacuate
+
+REST API for forcing down:
+==========================
+
+ Parameter explanations:
+ tenant_id: Identifier of the tenant.
+ binary: Compute service binary name.
+ host: Compute host name.
+ forced_down: Compute service forced down flag.
+ token: Token received after successful authentication.
+ service_host_ip: Serving controller node ip.
+
+ 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 forcing down:
+=====================
+
+ nova service-force-down <hostname> nova-compute
+
+ Example:
+ nova service-force-down compute1 nova-compute
+
+REST API for disabling forced down:
+===================================
+
+ Parameter explanations:
+ tenant_id: Identifier of the tenant.
+ binary: Compute service binary name.
+ host: Compute host name.
+ forced_down: Compute service forced down flag.
+ token: Token received after successful authentication.
+ service_host_ip: Serving controller node ip.
+
+ 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 <hostname> nova-compute
+
+ Example:
+ nova service-force-down --unset compute1 nova-compute