OpenStack Compute (Nova)
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melanie witt 63d2e62c3a Use subqueryload() instead of joinedload() for (system_)metadata
Currently, when we "get" a single instance from the database and we
load metadata and system_metadata, we do so using a joinedload() which
does JOINs with the respective tables. Because of the one-to-many
relationship between an instance and (system_)metadata records, doing
the database query this way can result in a large number of additional
rows being returned unnecessarily and cause a large data transfer.

This is similar to the problem addressed by change
I0610fb16ccce2ee95c318589c8abcc30613a3fe9 which added separate queries
for (system_)metadata when we "get" multiple instances. We don't,
however, reuse the same code for this change because
_instances_fill_metadata converts the instance database object to a
dict, and some callers of _instance_get_by_uuid need to be able to
access an instance database object attached to the session (example:
instance_update_and_get_original).

By using subqueryload() [1], we can perform the additional queries for
(system_)metadata to solve the problem with a similar approach.

Closes-Bug: #1799298

[1] https://docs.sqlalchemy.org/en/13/orm/loading_relationships.html#subquery-eager-loading

Change-Id: I5c071f70f669966e9807b38e99077c1cae5b4606
(cherry picked from commit e728fe668a)
2021-01-13 12:43:15 +00:00
api-guide/source lower-constraints: Bump packaging to 20.4 2020-12-11 17:08:48 +01:00
api-ref/source trivial: Final cleanup 2020-09-11 14:09:06 +01:00
devstack lower-constraints: Bump packaging to 20.4 2020-12-11 17:08:48 +01:00
doc Warn when starting services with older than N-1 computes 2021-01-05 17:11:43 +00:00
etc/nova Allow versioned discovery unauthenticated 2020-04-03 21:24:28 +00:00
gate lower-constraints: Bump packaging to 20.4 2020-12-11 17:08:48 +01:00
nova Use subqueryload() instead of joinedload() for (system_)metadata 2021-01-13 12:43:15 +00:00
playbooks zuul: Replace nova-live-migration with zuulv3 jobs 2020-11-30 09:43:51 +00:00
releasenotes Merge "Warn when starting services with older than N-1 computes" into stable/victoria 2021-01-10 01:54:35 +00:00
roles zuul: Replace nova-live-migration with zuulv3 jobs 2020-11-30 09:43:51 +00:00
tools Follow up for cherry-pick check for merge patch 2020-10-12 16:13:25 +00:00
.coveragerc Remove nova/openstack/* from .coveragerc 2016-10-12 16:20:49 -04:00
.gitignore tox: Integrate mypy 2020-05-15 15:59:53 +01:00
.gitreview [stable-only] Update .gitreview for stable/victoria 2020-09-25 14:16:20 +02:00
.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: Replace nova-live-migration with zuulv3 jobs 2020-11-30 09:43:51 +00:00
CONTRIBUTING.rst [Community goal] Update contributor documentation 2020-03-25 12:01:37 +00:00
HACKING.rst Remove hacking rules for python 2/3 compatibility 2020-06-17 08:19:13 +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 docs: Remove references to XenAPI driver 2020-08-31 15:53:31 +01:00
bindep.txt Add lsscsi to bindep 2020-08-05 16:16:49 -05:00
lower-constraints.txt lower-constraints: Bump packaging to 20.4 2020-12-11 17:08:48 +01:00
mypy-files.txt Add type hints to 'nova.virt.libvirt.utils' 2020-09-04 14:42:18 +01:00
requirements.txt Migrate default policy file from JSON to YAML 2020-09-09 08:09:38 -05:00
setup.cfg tox: Integrate mypy 2020-05-15 15:59:53 +01:00
setup.py Updated from global requirements 2017-03-02 11:50:48 +00:00
test-requirements.txt [goal] Prepare for job migration to Ubuntu Focal (20.04) 2020-08-18 11:28:32 +00:00
tox.ini [stable-only] Update TOX_CONSTRAINTS_FILE for stable/victoria 2020-09-25 14:18:11 +02:00

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, 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: