Async HeatStack may never be executed

[Stan Lagun]

As of recent there is an async parameter to HeatStack.push() method that allows to delay the push and do it asynchronously. The issue is that if the thread that called the push() methods happen to exit by that time the data will never be submitted to Heat. This can be demonstrated by making Instance destruction use async push. The instance is not going to be deleted because the destruction thread exits early.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/400409
Committed: https://git.openstack.org/cgit/openstack/murano/commit/?id=a19a66707badf4c6750c5fb3aea60ddfd67bdc88
Submitter: Jenkins
Branch: master

commit a19a66707badf4c6750c5fb3aea60ddfd67bdc88
Author: Stan Lagun <email address hidden>
Date: Mon Nov 21 13:18:34 2016 -0800

    HeatStack async mode fix

    Improve asynchronous push mode of HeatStack:
    - Use spawn_after instead of spawn_after_local. Otherwise the data is never
       pushed if the initiated thread were to exit
    - Cancel background thread instead of killing it. Cancel cancels the thread
       only if it hasn't started yet instead of killing it somewhere in the middle.
    - Add post-execution cleanup to guarantee that async data push happens
       before the execution session end
    - Make Instance destruction use async push to speed up the destruction
       in case when there are many servers and to test the HeatStack async mode

    Closes-Bug: #1643702
    Change-Id: I11d157844cb1d973d2cac62c2e6d67d047f75164

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/murano 3.1.0 release.