Open Stack

Can we start some background research on this topic? This ties up very
well with deprecating registry and it would be nice if we can determine
if registry is useful or not especially if we use different types of
rolling upgrade schemes (direct oslo.vo, expand/contract, etc.)



On 5/5/16 2:06 AM, Nikhil Komawar wrote:
> Hello everyone,
>
> Just wanted to send a brief summary of the discussions at the summit.
> This list is not holistic however, it covers the relevant aspects that
> various stakeholders need to be aware of.
>
>   * The intent is that we want operators to be able to upgrade from one
>     Glance release to the next with minimal (ideally, zero) downtime.
>
>   * Nova's been working on this, so there's a good example of how to
>     accomplish this. Also, the product working group has a cross-project
>     spec on this topic.
>
>   * Glance DB is the one component that would require some sophisticated
>     logic to avoid the downtime. Other services are being handled by
>     upgrade & swap mechanism.
>
>   * Some discussion was around relative comparison on what other
>     services are doing:In terms of performance there's simple schemain
>     Glance thoughcan have massive data.
>
>   *
>     The different approaches today include: 
>
>   *
>     oslo versioned objects
>
>   *
>     neutron: expansion/contraction scheme; expand, lazy updates, force
>     contract after some time
>
>   *
>     ironic: not using versioned objects, pinning the version
>
>   *
>     cinder: split across multiple releases - add table, code can handle both
>
>   * Besides these there was some discussion around best practices for
>     upgrades: The preferred upgrade scheme is first DB, then registry
>     and then API.
>
>   * There were some research items: documenting the draining protocol
>     for Glance nodes handling uploads. Write up alternatives in the spec
>     based on findings what other projects are achieving; sign-ups
>     include mclaren for cinder, rosmaita for neutron, nikhil for nova.
>     More volunteers are welcome.
>
> For more information please reach out to me on #openstack-glance, email,
> reply here etc.
>
>
>


-- 

Thanks,
Nikhil