[available-zone]az cachee in process make mistake

[xhzhf]

Description
===========
when getting in instance's detail info, AZ info is wrong

Steps to reproduce
==================
1.
in nova.conf, set memcached_servers = None

2.current az info:
nova aggregate-list
Id name Availability Zone
1 cas1-agg cas1
modifiy az info:
nova aggregate-update 1 cas1-agg cas2

3.get instance az info:
nova show ID

Expected result
===============
AZ info is cas2

Actual result
=============
AZ info is not stable.sometimes AZ is cas1, sometimes is cas2

Reason
===============
nova-api is multi-processing. When setting memcache server to none, nova-api will cache az in process memory. But nova-api processes caches are not consistent.
So I suggest nova-api does not cache az info in process memory.
Related file is nova/openstack/common/memorycached.py
Related class is Client.

[cissy (cissy.liu)]

1. which version of your openstack environment?
2. The memcached_servers option has deprecated in Mitaka for compute, So in my master branch of openstack after Newton the relation options is
[cache]
enabled=False
3.The result follow your step doesn't match your description.The az option of instance detail and the az info of the aggregate is same.
4.But when i follow the step , the result occurs again:
  1) nova az list----> internal / nova
  2) nova aggregate-create agg nova1
  3) nova aggregate-add-host agg <hostname> a VM running on the <hostname>
  4) nova show <vmname> focused on the az option of vm
    Excepted result
    ===============
    vm az info alway nova1
    Actual result
    ===============
    AZ info of vm is not stable, sometime is nova, sometime is nova1
I think your <Reason> description is right for above steps.

[Anusha Unnam (anusha-unnam)]

As the reporter of this bug hasn't updated the details, marking this bug as incomplete. Please provide the details about which version of your Openstack environment and change the status to new.

[Launchpad Janitor (janitor)]

[Expired for OpenStack Compute (nova) because there has been no activity for 60 days.]