Heartbeat ignores async actions

[Vitalii Solodilov]

Currently, the heartbeat ignores asynchronous actions when it
extracts expired actions:
https://github.com/openstack/mistral/blob/4a9ceaf47d24218e04c8c573fc144582e8553e73/mistral/db/v2/sqlalchemy/api.py#L1272

In some cases, async action can be stuck in the RUNNING state forever.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/599258

[Renat Akhmerov (rakhmerov)]

Please better explain what it all means and why the action heartbeat mechanism should care about asynchronous actions. A 3rd party that processes async actions can't send heartbeats to Mistral.

[Matt B (matty-brennan)]

If there was a heartbeat endpoint, a 3rd party process could hit it periodically. In our application we have an external service tightly integrated with mistral and would leverage this. Might make sense for the actions to be configurable in that case, since a normal 3rd party with a http callback probably wouldn't use it.

[Renat Akhmerov (rakhmerov)]

Yes, ok. We've never thought of this heartbeat mechanism as of something visible in the API. But your reasoning makes sense. I think we can extend it for this use case. I'd prefer to have a new BP for this though.

Thanks