880a356e40
This patch narrows down the race window between the filter running and
the consumption of resources from the instance after the host has been
chosen.
It does so by re-calculating the fitted NUMA topology just before consuming it
from the chosen host. Thus we avoid any locking, but also make sure that
the host_state is kept as up to date as possible for concurrent
requests, as there is no opportunity for switching threads inside a
consume_from_instance.
Several things worth noting:
* Scheduler being lock free (and thus racy) does not really affect
resources other than PCI and NUMA topology this badly - this is due
to complexity of said resources. In order for scheduler decesions to not
be based on basically guessing, in case of those two we will likely need
to introduce either locking or special heuristics.
* There is a lot of repeated code between the 'consume_from_instance'
method and the actual filters. This situation should really be fixed but
is out of scope for this bug fix (which is about preventing valid
requests failing because of races in the scheduler).
Change-Id: If0c7ad20506c9dddf4dec1eb64c9d6dd4fb75633
Closes-bug: #1438238
(cherry picked from commit
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contrib | ||
doc | ||
etc/nova | ||
nova | ||
plugins/xenserver | ||
tools | ||
.coveragerc | ||
.gitignore | ||
.gitreview | ||
.mailmap | ||
.testr.conf | ||
CONTRIBUTING.rst | ||
HACKING.rst | ||
LICENSE | ||
MANIFEST.in | ||
README.rst | ||
babel.cfg | ||
openstack-common.conf | ||
requirements.txt | ||
run_tests.sh | ||
setup.cfg | ||
setup.py | ||
test-requirements.txt | ||
tox.ini |
README.rst
OpenStack Nova README
OpenStack Nova provides a cloud computing fabric controller, supporting a wide variety of virtualization technologies, including KVM, Xen, LXC, VMware, and more. In addition to its native API, it includes compatibility with the commonly encountered Amazon EC2 and S3 APIs.
OpenStack Nova is distributed under the terms of the Apache License, Version 2.0. The full terms and conditions of this license are detailed in the LICENSE file.
Nova primarily consists of a set of Python daemons, though it requires and integrates with a number of native system components for databases, messaging and virtualization capabilities.
To keep updated with new developments in the OpenStack project follow @openstack on Twitter.
To learn how to deploy OpenStack Nova, consult the documentation available online at:
For information about the different compute (hypervisor) drivers supported by Nova, read this page on the wiki:
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 wishing to work on the OpenStack Nova project should always base their work on the latest Nova code, available from the master GIT repository at:
Developers should also join the discussion on the mailing list, at:
http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
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:
For information on how to contribute to Nova, please see the contents of the CONTRIBUTING.rst file.
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