Open Stack

>________________________________________
>From: Jay Pipes [jaypipes at gmail.com]
>Sent: Monday, September 22, 2014 11:51 AM
>To: openstack-dev at lists.openstack.org
>Subject: Re: [openstack-dev] [Nova] - do we need .start and .end notifications in all cases ?
>
>On 09/22/2014 07:37 AM, Sandy Walsh wrote:
>> For some operations like resize, migrate, etc., the .start/.end is
>> good for auditing and billing. Although, we could do a better job by
>>  simply managing the launched_at, deleted_at times better.
>
>I'm sure I'll get no real disagreement from you or Andrew Laski on
>this... but the above is one of the reasons we really should be moving
>with pace towards a fully task-driven system, both internally in Nova
>and externally via the Compute REST API. This would allow us to get rid
>of the launched_at, deleted_at, created_at, updated_at, etc fields in
>many of the database tables and instead have a data store for tasks
>RDBMS or otherwise) that had start and end times in the task record,
>along with codified task types.
>
>You can see what I had in mind for the public-facing side of this here:
>
>http://docs.oscomputevnext.apiary.io/#schema
>
>See the schema for server task and server task item.

Totally agree. Though I would go one step further and say the Task state
transitions should be managed by notifications.

Then oslo.messaging is reduced to the simple notifications interface (no RPC).
Notification follow proper retry semantics and control Tasks. 
Tasks themselves can restart/retry/etc.

(I'm sure I'm singing to the choir)

-S