Re: [alto] How Data Center Virtualization influence ALTO mechanism.

["Y.J. GU" <[e-mail]>]

I don't see the protocol implications either for now. But I think this is an implementation issue that ALTO needs to consider. ALTO doesn't care about how the information is collected, however ALTO need to define how the network map should be like in this scenario, will the cost map change as well? 
And VMs migration might be a strong motivation for ALTO Server to update the ALTO information that has been distributed among the network.




> -----Original Message-----
> From: stefano previdi [mailto:[e-mail]]
> Sent: Wednesday, October 13, 2010 7:22 PM
> To: Y.J. GU
> Cc: [e-mail]
> Subject: Re: [alto] How Data Center Virtualization influence ALTO mechanism.
> 
> 
> On Oct 9, 2010, at 9:18 AM, Y.J. GU wrote:
> 
> > Hi all,
> > I was thinking about how Data Center Virtualization and Virtual
> > Machine(VM) Migration will influence ALTO mechanism.
> >
> > Current ALTO Protocol defines clustering of peers according to their
> > IP Addresses. E.g. peers in same subnet will be classified into same
> > PID, and path cost will indicate the cost within and between PIDs,
> > which is also actually based on IP Addresses.
> 
> the methods of grouping are orthogonal to ALTO protocol specification.
> 
> There are ALTO implementations that allow address/prefixes grouping
> relaxed from pure IP aggregation. The fact that you use IP addresses
> in the protocol doesn't mean that locality is solely based on
> address/mask pairs.
> 
> It is mostly a policy definition by the ALTO and infrastructure
> operator.
> 
> 
> > In the current world, peers are partitioned by IP subnet. While
> > considering virtual machines migration, there might be more
> > interesting things to think of.
> >
> > In Data Center operation, one basic consensus is 'When Virtual
> > Machines move from one site to another, the IP Addresses will not
> > change, so that the existing service connection will not be
> > broken'.  VMs can migrate to arbitrary site, not under the control
> > and knowledge of ISP. For example, some VMs in Data Center A(IP
> > subnet 198.1.1.0) move to Data Center B (IP subnet 210.1.1.0). IP-
> > based, Vms are closer to DC-A. Physically, these VMs are much closer
> > to hosts in DC-B. However things are not so easy, especially
> > considering how these VMs are routed. Current ALTO may give wrong
> > cost ranking.
> 
> 
> that is true. ALTO relies on accurate infrastructure/topology
> information. It can be derived from lower layers (routing and below)
> or inferred by policy DBs.
> 
> 
> > VMs may migrate under, but not limited to, these situations: 1) to
> > save electricity power, 2) disaster recovery, 3) customer prefer
> > another Data Center, 4) company extension, etc. In the end, the
> > internet will not be a regular world partitioned by IP Addresses.
> 
> 
> the "swamp" already validated the theory...
> 
> 
> > Does anyone think this is an interesting aspect to study?
> 
> probably yes but I'm not sure I see the protocol implication.
> 
> s.
>