[ofa-general] Re: Default multicast group rate

[Sasha Khapyorsky]

On 16:50 Fri 13 Apr     , Michael S. Tsirkin wrote:
> > So the question is whether the best default is 2.5 Gbps which would
> > allow any nodes to join or whether the current default is appropriate ?
> > I know certain people's opinions who have been vocal on this list up to
> > now. I'm looking for other opinions. Thanks.
> 
> Just as a summary of what I was saying in another thread,
> I propose implementing a dynamic approach, where we start at
> 4x DDR, and drop the rate gradually as lower rate nodes join,
> or raise the rate when all lower rate nodes have left.
> 
> reregister can be used to let existing members know that
> rate has changed.

Reregistration is not easy process and it does not scale very well - in
order to join only one slow port you will need to reregister a whole
cluster. Also I remember some issues with such massive re-registrations
like dropped and reordered MADs.

> Later, a spec extension can be designed
> to notify group members about rate change.

I think we should start to discuss dynamic approach at this point - I
don't like full reregistration option.

Sasha