In nova.db.sqlalchemy.model.ComputeNode, column hypervisor_hostname should be unique values

[Kanagaraj Manickam]

In the nova model nova.db.sqlalchemy.model.ComputeNode, the column represents the hypervisor name and is not set to unique and not null values. This leads to have same hyerpvisor host name for more than one hypervisors and will end up in error scenarios.

In order to avoid the this scenario, column should be set to following values
nullable=False
unique=True

This bug is filed to address the same.

[Kanagaraj Manickam (kanagaraj-manickam)]

Hi Sean Dague,

This defect will affect almost all hypervisors and it will mandates lots of unit testing to be done across all the hypervisor supported drivers. so I am waiting for kilo to open up for the putting the code changes.

Also i am investigating whether we need to make this as blue print, kindly suggest. Thanks.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/187844

[Auktavian Garrett (augarret)]

This code review fixes failing test cases made by changing hypervisor_hostname db column to nullable=False and unique=True. These test cases do not necessarily test that functionality.
Should separate test cases be created to test this functionality? Nullable hypervisor_hostname columns created within the db was causing failures before

[OpenStack Infra (hudson-openstack)]

Change abandoned by Michael Still (<email address hidden>) on branch: master
Review: https://review.openstack.org/187844
Reason: This patch has been stalled for quite a while, so I am going to abandon it to keep the code review queue sane. Please restore the change when it is ready for review.

[Sean Dague (sdague)]

Please do not assign yourself to a bug unless you have pushed up a real patch on this.

[Markus Zoeller (markus_z) (mzoeller)]

The age and number of assignee changes suggest that this isn't really
a low-hanging-fruit. I'm removing the tag to not confuse new folks who
are searching for that tag.

[Markus Zoeller (markus_z) (mzoeller)]

This is an automated cleanup. This bug report has been closed because it
is older than 18 months and there is no open code change to fix this.
After this time it is unlikely that the circumstances which lead to
the observed issue can be reproduced.

If you can reproduce the bug, please:
* reopen the bug report (set to status "New")
* AND add the detailed steps to reproduce the issue (if applicable)
* AND leave a comment "CONFIRMED FOR: <RELEASE_NAME>"
  Only still supported release names are valid (LIBERTY, MITAKA, OCATA, NEWTON).
  Valid example: CONFIRMED FOR: LIBERTY