03f6989f4e
Update doc links according to OpenStack document migration Change-Id: Ib2a3f550404d72b4ad4427747a7894eb40feecb7
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3.4 KiB
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160 lines
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This work is licensed under a Creative Commons Attribution 3.0 Unported
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License.
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http://creativecommons.org/licenses/by/3.0/legalcode
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====================================
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Report backend state in service list
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====================================
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https://blueprints.launchpad.net/cinder/+spec/report-backend-state-in-service-list
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Storage driver reports state of backend storage device and let admin operator
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know it via service list for maintenance purpose.
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Problem description
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===================
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Currently, Cinder couldn't report backend state to service, operators only
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know that cinder-volume process is up, but isn't aware of whether the backend
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storage device is ok. Users still can create volume and go to fail over and
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over again. To make maintenance easier, operator could query storage device
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state via service list and fix the problem more quickly. If device state is
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*down*, that means volume creation will fail.
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Use Cases
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=========
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In large scale cloud system, there could be many backends existing in the
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system. If volume, snapshot or other resources creation goes to failure,
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operators or cloud management system could query the service first and get
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the backend device state in every service. If device state is *down*, specify
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that storage device has got some problems. Give operators/management system
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more information to locate bug more quickly.
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Proposed change
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===============
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* Each driver reports the backend state in "get_volume_stats" by adding
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key/value: "backend_state: up/down"[1].
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* When calling 'service list', get this information from scheduler for every
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backend.
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* Add 'backend_state: up/down' in response body of service list API if context
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is admin.
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* Before all drivers support this feature, if the result of get_volume_stats
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doesn't include the backend state, Cinder will set backend_state to 'up' by
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default.
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Alternatives
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------------
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Add cinder manage command to query backend device state from driver directly.
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Data model impact
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-----------------
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None
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REST API impact
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---------------
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Add backend_state: up/down into response body of service list and also need
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a microversions for this feature:
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.. code-block:: console
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GET /v3/{project_id}/os-services
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RESP BODY:
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.. code-block:: python
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{"services": [{"host": "host@backend1",
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...,
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"backend_status": "up",
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},
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{"host": "host@backend2",
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...,
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"backend_status": "down",
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}]
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}
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Security impact
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---------------
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None
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Notifications impact
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--------------------
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None.
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Other end user impact
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---------------------
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None
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Performance Impact
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------------------
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None
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Other deployer impact
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---------------------
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None
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Developer impact
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----------------
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Driver maintainer needs to add backend state when reporting
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volume stats.
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Implementation
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==============
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Assignee(s)
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-----------
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Primary assignee:
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wanghao<wanghao749@huawei.com>
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Work Items
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----------
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* Implement code in Cinder API and scheduler.
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* Update cinderclient to support this function.
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* Add change to API doc.
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Dependencies
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============
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None
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Testing
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=======
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Both unit and Tempest tests need to be created to cover the code change that
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mentioned in "Proposed change".
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Documentation Impact
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====================
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1. The cinder API documentation will need to be updated to reflect the REST
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API changes.
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References
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==========
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[1]https://docs.openstack.org/cinder/latest/contributor/drivers.html
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