https://review.openstack.org/174779
commit 6f1f9dbc211356a3d0e2d46d3a984d7ceee79ca6
Author: Tony Breeds <email address hidden>
Date: Tue Jan 27 11:17:54 2015 -0800
Allow disabling the evacuate cleanup mechanism in compute manager
This mechanism attempts to destroy any locally-running instances on
startup if instance.host != self.host. The assumption is that the
instance has been evacuated and is safely running elsewhere. This is
a dangerous assumption to make, so this patch adds a configuration
variable to disable this behavior if it's not desired.
Note that disabling it may have implications for the case where
instances *were* evacuated, given potential shared resources.
To counter that problem, this patch also makes _init_instance()
skip initialization of the instance if it appears to be owned
by another host, logging a prominent warning in that case.
As a result, if you have destroy_after_evacuate=False and you start
a nova compute with an incorrect hostname, or run it twice from
another host, then the worst that will happen is you get log
warnings about the instances on the host being ignored. This should
be an indication that something is wrong, but still allow for
fixing it without any loss. If the configuration option is disabled
and a legitimate evacuation does occur, simply enabling it and then
restarting the compute service will cause the cleanup to occur.
This is added to the workarounds config group because it is really
only relevant while evacuate is fundamentally broken in this way.
It needs to be refactored to be more robust, and once that is done,
this should be able to go away.
Conflicts:
nova/compute/manager.py
nova/tests/unit/compute/test_compute.py
nova/tests/unit/compute/test_compute_mgr.py
nova/utils.py
NOTE: In nova/utils.py a new section has been introduced but
only the option addessed by this backport has been included.
DocImpact: New configuration option, and peril warning
Partial-Bug: #1419785
(cherry picked from commit 922148ac45c5a70da8969815b4f47e3c758d6974)
-- squashed with commit --
Create a 'workarounds' config group.
This group is for very specific reasons.
If you're:
- Working around an issue in a system tool (e.g. libvirt or qemu) where the fix
is in flight/discussed in that community.
- The tool can be/is fixed in some distributions and rather than patch the code
those distributions can trivially set a config option to get the "correct"
behavior.
This is a good place for your workaround.
(cherry picked from commit b1689b58409ab97ef64b8cec2ba3773aacca7ac5)
--
Change-Id: Ib9a3c72c096822dd5c65c905117ae14994c73e99
Fix proposed to branch: master
Review: https:/