[OpenAFS-devel] Ubik voting idea

[Ted McCabe]

At 10:09 AM -0700 10/3/01, Matthew Andrews wrote:
>yes, but wouldn't this need to be on all machines in case the designator
>machine was down, and someone else got voted the designator? looks like
>we still have the same problem.

The problem being addressed is that if two db servers have different 
voting preferences they might vote in a way that causes deadlock, at 
worst, or hairy coding problems, at best.  Yet there is a desire at 
some sites that the lowest IP address DB server not be the sync-site.

The designator going down would cause voting for a new designator to 
happen.  The new designator need not choose the same sync-site as 
before, in fact it need not have the same preferences as before.  The 
point of voting is to know that we have quorum and to choose a 
sync-site from among the quorum members.  The aforementioned idea is 
basically to separate the responsibility of knowing there is quorum 
(designator) from the responsibility of managing db writes 
(sync-site).  A sync-site would only have authority because it is 
named by the designator, the process for which would need to be 
designed.  I believe clients need not be aware of any of this (other 
than the usual downtime currently present during voting).

Am I missing something?

    --Ted