OpenStack Compute (Nova)
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Stephen Finucane ce95af2caf Don't unset Instance.old_flavor, new_flavor until necessary
Since change Ia6d8a7909081b0b856bd7e290e234af7e42a2b38, the resource
tracker's 'drop_move_claim' method has been capable of freeing up
resource usage. However, this relies on accurate resource reporting.
It transpires that there's a race whereby the resource tracker's
'update_available_resource' periodic task can end up not accounting for
usage from migrations that are in the process of being completed. The
root cause is the resource tracker's reliance on the stashed flavor in a
given migration record [1]. Previously, this information was deleted by
the compute manager at the start of the confirm migration operation [2].
The compute manager would then call the virt driver [3], which could
take a not insignificant amount of time to return, before finally
dropping the move claim. If the periodic task ran between the clearing
of the stashed flavor and the return of the virt driver, it would find a
migration record with no stashed flavor and would therefore ignore this
record for accounting purposes [4], resulting in an incorrect record for
the compute node, and an exception when the 'drop_move_claim' attempts
to free up the resources that aren't being tracked.

The solution to this issue is pretty simple. Instead of unsetting the
old flavor record from the migration at the start of the various move
operations, do it afterwards.

[1] https://github.com/openstack/nova/blob/6557d67/nova/compute/resource_tracker.py#L1288
[2] https://github.com/openstack/nova/blob/6557d67/nova/compute/manager.py#L4310-L4315
[3] https://github.com/openstack/nova/blob/6557d67/nova/compute/manager.py#L4330-L4331
[4] https://github.com/openstack/nova/blob/6557d67/nova/compute/resource_tracker.py#L1300

Change-Id: I4760b01b695c94fa371b72216d398388cf981d28
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
Partial-Bug: #1879878
Related-Bug: #1834349
Related-Bug: #1818914
(cherry picked from commit 44376d2e21)
2020-09-11 17:23:07 +01:00
api-guide/source Add release notes for Cyborg-Nova integration. 2020-04-03 17:13:04 +08:00
api-ref/source compute: Validate a BDMs disk_bus when provided 2020-08-03 21:31:25 +01:00
devstack Merge "Find instance in another cell during floating IP re-association" 2019-09-13 15:19:55 +00:00
doc Add note and daxio version to the vPMEM document 2020-09-03 09:05:41 +00:00
etc/nova Allow versioned discovery unauthenticated 2020-04-03 21:24:28 +00:00
gate nova-live-migration: Only stop n-cpu and q-agt during evacuation testing 2020-03-21 17:08:47 +00:00
nova Don't unset Instance.old_flavor, new_flavor until necessary 2020-09-11 17:23:07 +01:00
playbooks Enable cross-cell resize in the nova-multi-cell job 2019-12-23 10:10:57 -05:00
releasenotes Add a lock to prevent race during detach/attach of interface 2020-08-31 11:32:44 +00:00
roles Enable cross-cell resize in the nova-multi-cell job 2019-12-23 10:10:57 -05:00
tools Fix cherry-pick check for merge patch 2020-07-03 10:01:28 +02:00
.coveragerc Remove nova/openstack/* from .coveragerc 2016-10-12 16:20:49 -04:00
.gitignore Delete the placement code 2019-04-28 20:06:15 +00:00
.gitreview Update .gitreview for stable/ussuri 2020-04-23 21:37:31 +00:00
.mailmap Add mailmap entry 2014-05-07 12:14:26 -07:00
.pre-commit-config.yaml Switch to hacking 2.x 2020-01-17 11:30:40 +00:00
.stestr.conf Finish stestr migration 2017-11-24 16:51:12 -05:00
.zuul.yaml zuul: remove legacy-tempest-dsvm-neutron-dvr-multinode-full 2020-07-17 09:44:08 +02:00
CONTRIBUTING.rst [Community goal] Update contributor documentation 2020-03-25 12:01:37 +00:00
HACKING.rst Merge "Make it easier to run a selection of tests relevant to ongoing work" 2019-11-22 20:58:18 +00:00
LICENSE initial commit 2010-05-27 23:05:26 -07:00
MAINTAINERS Fix broken URLs 2017-09-07 15:42:31 +02:00
README.rst Start README.rst with a better title 2019-11-19 17:29:28 +01:00
babel.cfg Get rid of distutils.extra. 2012-02-08 19:30:39 -08:00
bindep.txt Added openssh-client into bindep 2019-10-23 07:21:23 +00:00
lower-constraints.txt Merge "Use oslo policy flag to disable default change warning instead of all" 2020-04-21 10:04:19 +00:00
requirements.txt Merge "Use oslo policy flag to disable default change warning instead of all" 2020-04-21 10:04:19 +00:00
setup.cfg api: Add support for new cyborg extra specs 2020-04-08 13:19:39 +00:00
setup.py Updated from global requirements 2017-03-02 11:50:48 +00:00
test-requirements.txt Bump hacking min version to 3.0.1 2020-05-18 09:48:56 +00:00
tox.ini Check cherry-pick hashes in pep8 tox target 2020-06-16 06:47:20 -07:00

README.rst

OpenStack Nova

image

OpenStack Nova provides a cloud computing fabric controller, supporting a wide variety of compute technologies, including: libvirt (KVM, Xen, LXC and more), Hyper-V, VMware, XenServer, OpenStack Ironic and PowerVM.

Use the following resources to learn more.

API

To learn how to use Nova's API, consult the documentation available online at:

For more information on OpenStack APIs, SDKs and CLIs in general, refer to:

Operators

To learn how to deploy and configure OpenStack Nova, consult the documentation available online at:

In the unfortunate event that bugs are discovered, they should be reported to the appropriate bug tracker. If you obtained the software from a 3rd party operating system vendor, it is often wise to use their own bug tracker for reporting problems. In all other cases use the master OpenStack bug tracker, available at:

Developers

For information on how to contribute to Nova, please see the contents of the CONTRIBUTING.rst.

Any new code must follow the development guidelines detailed in the HACKING.rst file, and pass all unit tests.

Further developer focused documentation is available at:

Other Information

During each Summit and Project Team Gathering, we agree on what the whole community wants to focus on for the upcoming release. The plans for nova can be found at: