Re: [Gluster-devel] RFC - "Connection Groups" concept

[Jeff Darcy]

On 06/27/2013 09:37 AM, Stephan von Krawczynski wrote:
> On Wed, 26 Jun 2013 11:04:07 -0400 Jeff Darcy <address@hidden>
> wrote:
>
> > [Jeff on UUIDs]
>
> I generally vote against using UUIDs and for IPs. In runtime I can
> easily switch an IP in a replacement situation, but can I switch a
> UUID in the same easy manner?

I don't see why that would be problematic.  The UUIDs we're talking
about aren't tied to hardware.  They're essentially big random numbers
we assign ourselves.  IIRC they're just stored in a file, so they can be
trivially copied from a system to its replacement.  The problem is
precisely that DNS names and IP addresses aren't good *system*
identifiers.  For one thing, they refer to interfaces rather than
systems (which might have many interfaces).  For another, even that
association is too transient.  Such IDs are convenient for referring to
a system *at a specific point in time* but not permanently, and a
permanent ID for the whole system is something we really need.  It sure
would be nice if the networking community would stop ****ing around when
it comes to multi-homed or mobile hosts, but they don't seem inclined to
so the rest of us have to fall back on other established patterns for
identifying hosts separately from their addresses.