compute resource providers not equal to compute nodes in deployment

> su -s /bin/sh -c "nova-manage cell_v2 discover_hosts --verbose" nova
The deleted compute node will be added again as a new node.

That doesn't actually have anything to do with the compute node records getting re-created after you delete the service records.

Are you actually stopping the nova-compute service before you delete the service records via the API? Because if not, there is a periodic task in the nova-compute service that will automatically re-create the compute_nodes records in the database.

See the note in the API reference:

https://developer.openstack.org/api-ref/compute/#delete-compute-service

This is also related:

https://bugs.launchpad.net/nova/+bug/1756179

Hi Matt,

I had stopped the nova-compute service.
The issue is with the Placement API which created duplicates of the records.

[Expired for OpenStack Compute (nova) because there has been no activity for 60 days.]

Shouldn't the upgrade check simply discount deleted compute_nodes ?

+-----------------------------------------------------------------------+
| Check: Resource Providers |
| Result: Warning |
| Details: There are 34 compute resource providers and 40 compute nodes |
| in the deployment. Ideally the number of compute resource |
| providers should equal the number of enabled compute nodes |
| otherwise the cloud may be underutilized. See |
| https://docs.openstack.org/nova/latest/user/placement.html |
| for more details. |
+-----------------------------------------------------------------------+

mysql> select count(*) from compute_nodes;
+----------+
| count(*) |
+----------+
| 40 |
+----------+
1 row in set (0.00 sec)

mysql> select count(*) from compute_nodes where deleted=0;
+----------+
| count(*) |
+----------+
| 34 |
+----------+
1 row in set (0.00 sec)

It appears that not accounting for deleted is discussed here: https://github.com/openstack/nova/blob/6be7f7248fb1c2bbb890a0a48a424e205e173c9c/nova/cmd/status.py#L114-L128

It does seem a bit weird.

"disabled" is one thing - you can come back from that - but "deleted" is a one-way ticket ... no?

Fix proposed to branch: master
Review: https://review.openstack.org/604495

Reviewed: https://review.openstack.org/604495
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=3e902313e9c3117e76d6adf88a2f104bc229374c
Submitter: Zuul
Branch: master

commit 3e902313e9c3117e76d6adf88a2f104bc229374c
Author: imacdonn <email address hidden>
Date: Sat Sep 22 00:55:36 2018 +0000

    nova-status - don't count deleted compute_nodes

    When counting rows in the compute_nodes table to compare against
    resource records, those which have been marked as deleted should
    not be counted, otherwise the result is artificially high.

    Change-Id: Ia3fbb9c46c15826fc363286ce48984f59cbe1e62
    Closes-Bug: #1757207

Fix proposed to branch: stable/rocky
Review: https://review.openstack.org/604785

Fix proposed to branch: stable/queens
Review: https://review.openstack.org/604786

Fix proposed to branch: stable/pike
Review: https://review.openstack.org/604788

Reviewed: https://review.openstack.org/604785
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=c559c5b357f47ae2bed9397bbfb8b2e08dc5b8a5
Submitter: Zuul
Branch: stable/rocky

commit c559c5b357f47ae2bed9397bbfb8b2e08dc5b8a5
Author: imacdonn <email address hidden>
Date: Sat Sep 22 00:55:36 2018 +0000

    nova-status - don't count deleted compute_nodes

    When counting rows in the compute_nodes table to compare against
    resource records, those which have been marked as deleted should
    not be counted, otherwise the result is artificially high.

    Change-Id: Ia3fbb9c46c15826fc363286ce48984f59cbe1e62
    Closes-Bug: #1757207
    (cherry picked from commit 3e902313e9c3117e76d6adf88a2f104bc229374c)

Reviewed: https://review.openstack.org/604786
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=72d2e82e1275035c70cb6862ff15dc41b3d9b621
Submitter: Zuul
Branch: stable/queens

commit 72d2e82e1275035c70cb6862ff15dc41b3d9b621
Author: imacdonn <email address hidden>
Date: Sat Sep 22 00:55:36 2018 +0000

    nova-status - don't count deleted compute_nodes

    When counting rows in the compute_nodes table to compare against
    resource records, those which have been marked as deleted should
    not be counted, otherwise the result is artificially high.

    Change-Id: Ia3fbb9c46c15826fc363286ce48984f59cbe1e62
    Closes-Bug: #1757207
    (cherry picked from commit 3e902313e9c3117e76d6adf88a2f104bc229374c)

Reviewed: https://review.openstack.org/604788
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=ef5c02209a28510eee66edc8495acc6cd4e0993a
Submitter: Zuul
Branch: stable/pike

commit ef5c02209a28510eee66edc8495acc6cd4e0993a
Author: imacdonn <email address hidden>
Date: Sat Sep 22 00:55:36 2018 +0000

    nova-status - don't count deleted compute_nodes

    When counting rows in the compute_nodes table to compare against
    resource records, those which have been marked as deleted should
    not be counted, otherwise the result is artificially high.

    Change-Id: Ia3fbb9c46c15826fc363286ce48984f59cbe1e62
    Closes-Bug: #1757207
    (cherry picked from commit 3e902313e9c3117e76d6adf88a2f104bc229374c)

This issue was fixed in the openstack/nova 18.0.2 release.

This issue was fixed in the openstack/nova 16.1.6 release.

This issue was fixed in the openstack/nova 17.0.7 release.

This issue was fixed in the openstack/nova 19.0.0.0rc1 release candidate.