35 lines
1.5 KiB
YAML
35 lines
1.5 KiB
YAML
---
|
|
issues:
|
|
- |
|
|
In Stein the Placement service is available either as part of Nova, or
|
|
independently packaged from its own project. This is to allow easier
|
|
migration from one to another. See the `upgrade notes`_ for more
|
|
information.
|
|
|
|
When using the Placement packaged from Nova, some deployment strategies can
|
|
lead to the service stalling with error messages similar to::
|
|
|
|
Traceback (most recent call last):
|
|
File "/usr/lib/python2.7/site-packages/eventlet/hubs/hub.py", line 460, in fire_timers
|
|
timer()
|
|
File "/usr/lib/python2.7/site-packages/eventlet/hubs/timer.py", line 59, in __call__
|
|
cb(*args, **kw)
|
|
File "/usr/lib/python2.7/site-packages/eventlet/semaphore.py", line 147, in _do_acquire
|
|
waiter.switch()
|
|
error: cannot switch to a different thread
|
|
|
|
The reasons this is happening are discussed in bug 1829062_. There are
|
|
three workarounds available:
|
|
|
|
* In the environment of the web server running the placement service, set
|
|
``OS_NOVA_DISABLE_EVENTLET_PATCHING=yes`` so that eventlet does not
|
|
conflict with thread handling in the web server.
|
|
|
|
* Turn off threading in the web server. For example, if using ``mod_wsgi``
|
|
or ``uwsgi``, set ``threads=1`` in their respective configurations.
|
|
|
|
* Switch to using the extracted placement. It does not suffer from eventlet.
|
|
|
|
.. _upgrade notes: https://docs.openstack.org/placement/latest/upgrade/to-stein.html
|
|
.. _1829062: https://bugs.launchpad.net/nova/+bug/1829062
|