Re: [patch 2/6] [Network namespace] Network device sharing by view

Herbert,

On Tue, Jun 27, 2006 at 05:48:19PM +0200, Herbert Poetzl wrote:

On Tue, Jun 27, 2006 at 01:09:11PM +0400, Andrey Savochkin wrote:

quoted

On Mon, Jun 26, 2006 at 10:02:25PM +0200, Herbert Poetzl wrote:

quoted

 - traffic between guests
   can be as high (or even higher) than the
   outbound traffic, just think web guest and
   database guest

My experience with host-guest systems tells me the opposite: outside
traffic is a way higher than traffic between guests. People put web
server and database in different guests not more frequent than they
put them on separate physical server. Unless people are building a
really huge system when 1 server can't take the whole load, web and
database live together and benefit from communications over UNIX
sockets.

well, that's probably because you (or your company)
focuses on providers which simply (re)sell the entities
to their customers, in which case it would be more
expensive to put e.g. the database into a separate
guest. but let me state here that this is not the only
application for this technology

I'm just sharing my experience.
You have one experience, I have another, and your classification of traffic
importance is not the universal one.
My point was that we shouldn't overestimate the use of INET sockets vs. UNIX
ones in configurations where communications but not web/db operations play a
big role in overall performance.
And indeed I've talked with many different people, from universities to
large enterprises.

[snip]

quoted

I'd like to caution about over-optimizing communications between
different network namespaces. Many optimizations of local traffic
(such as high MTU) don't look so appealing when you start to think
about live migration of namespaces.

I think the 'optimization' (or to be precise: desire
not to sacrifice local/loopback traffic for some use
case as you describe it) does not interfere with live
migration at all, we still will have 'local' and 'remote'
traffic, and personally I doubt that the live migration
is a feature for the masses ...

Why not for the masses?

	Andrey