all periodic_task died due to uncaught exceptions

[xhzhf]

Description
===========
all periodic tasks of nova-compute don't work in environment of our customers
report_state works.

Steps to reproduce
==================
after some error of our virtulization product happened.
At that time, get_available_nodes of the driver can not fulfil and throw a exception that does nto inherit from Excetipn

Analysis
=============
I found that the coroutine has disappear and run_periodic_tasks in periodic_task.py does not catch BaseException

Solution
=============
run_periodic_tasks should catch all exception.
This is a major problem. All periodic_task died even those tasks which work well and don't throw exception.
Because they belong to a same coroutine.
We should keep nova-compute robust.

Environment
===========
1. Exact version of OpenStack you are running. See the following
  list for all releases: http://docs.openstack.org/releases/
   openstack-nova-common-16.0.1-1.el7.noarch
   python2-novaclient-9.1.0-1.noarch
   python-nova-16.0.1-1.el7.noarch
   openstack-nova-compute-16.0.1-1.noarch

2. Which hypervisor did you use?
   Our own virtulization product

2. Which storage type did you use?
   None

3. Which networking type did you use?
   Neutron with our sdn

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/518249

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/518249
Committed: https://git.openstack.org/cgit/openstack/oslo.service/commit/?id=b96538fcb46ba9b5656ed07b5b75874d3125eb9e
Submitter: Zuul
Branch: master

commit b96538fcb46ba9b5656ed07b5b75874d3125eb9e
Author: xhzhf <[e-mail]>
Date: Tue Nov 7 11:56:04 2017 +0800

    change periodic_task to catch all exceptions including BaseException

    the function of periodic_task does not catch all exception so that
    all periodic task will die if one periodic task throw BaseException
    Closes-Bug: #1730556

    Change-Id: I2819cd3644aacac86bc6d12c980d8902f1a71823

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/oslo.service 1.27.0 release.