e0bf455f7e
The 'scheduled_at' field is a part of the Nova instances. Currently, the 'scheduled_at' field is no longer updated by the Nova scheduler, instead the 'launched_at' field is updated for the same purpose. The 'scheduled_at' column is now redundant and should be removed as a part of DB clean up. Change-Id: I7ccf1d225c983b69c05f2415094071bdafd63b85 Blueprint: cleanup-scheduled-at
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..
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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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Cleanup 'scheduled_at' column in nova instances table
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=====================================================
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https://blueprints.launchpad.net/nova/+spec/cleanup-scheduled-at
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The 'scheduled_at' field is a part of the Nova instances table
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Currently, the 'scheduled_at' field is no longer updated by the
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Nova scheduler, instead the 'launched_at' field is used.
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The 'scheduled_at' column is now redundant and should
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be removed as a part of DB clean up.
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Problem description
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===================
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The 'scheduled_at' column in the nova instances table is now
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redundant. This field was erstwhile used by the scheduler to denote
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the time of the instance scheduling. The commit that removed it is:
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https://review.openstack.org/#/c/143725/
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Now since all of the basic VM lifecyle operations go through the
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scheduler, the 'launched_at' field is sufficient for the above
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mentioned scenario.
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This is a nova DB cleanup effort to get removed the 'scheduled_at'
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column from the instances table and ensure backward compatibility.
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Use Cases
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----------
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This is a cleanup effort on the instances table.
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Project Priority
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-----------------
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This is a refactoring effort to make nova code cleaner.
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Proposed change
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===============
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Estimated changes are going to be in the following places:
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* Remove the sqlalchemy initializations for the 'scheduled_at' field
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* Remove all unit tests, involving this field.
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* Ensure that the NovaObjects adapt to this change for handling
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migration related issues.
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Alternatives
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------------
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Continue to live with dormant code in nova.
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Data model impact
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-----------------
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The 'scheduled_at' column can be dropped from the Instances table since
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there appears to be no code, that updates it currently.
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REST API impact
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---------------
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None
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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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None
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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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* Sudipta Biswas sbiswas7
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Work Items
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----------
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1. Drop the column for 'scheduled_at' from Sqlalchemy model.
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2. Add migration to drop the column from the instances table.
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3. Change the instances object module for migration related issues.
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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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The changes will be exercised through the existing CI.
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Documentation Impact
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====================
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None
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References
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==========
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