|
On Mon, May 31, 2004 at 05:29:32PM +0100, ed wrote:
> On Mon, 31 May 2004 20:13:37 +0900
> Horms <horms@xxxxxxxxxxxx> wrote:
>
> > > a)
> > >
> > > +------------------+
> > > | virtual server |
> > > | 212.22.96.10 |
> > > +--------+---------+
> > > |
> > > +--------+---------+
> > > | switch/hub |
> > > +--------+---------+
> > > |
> > > |
> > > +-------------+--------+-----+
> > > | | |
> > > +---+----+ +---+----+ +----+---+
> > > | server | | server | | server |
> > > +--------+ +--------+ +--------+
> > >
> > > b)
> > >
> > > +--------+---------+
> > > | switch/hub |
> > > +--------+---------+
> > > |
> > > +-------------+-------++-----+
> > > | | | |
> > > +---+----+ +---+----+ | +----+---+
> > > | server | | server | | | server |
> > > +--------+ +--------+ | +--------+
> > > |
> > > +-------+----------+
> > > | virtual server |
> > > | 212.22.96.10 |
> > > +------------------+
> > >
> > > (I appologise for bad ascii).
> >
> > Hi Ed,
> >
> > Interesting project. Unfortunately I don't understand the difference
> > between the two dagrams above. Could you explain a little more?
>
> Certainally, in drawing 'a' the virtual server has two interfaces, and
> eth0 would be the external interface, and eth1 would be its internal
> pool of servers. I just wondered if the servers had to be on a seperate
> network to avoid confusion with clients or other server pools.
>
> Drawing b hows both the vertual server and cluster computers on the same
> network.
Ok, understood.
The answer is that you can do either.
a) would be an LVS-NAT setup. This is generally easier to get working
as it requires no modification to the real servers (servers). However
you do need to ad an iptables-NAT rule on the linux director (virtual
server) if you want the real servers to be able to _establish_
connections to the outside world.
b) would be an LVS-DR setup. This can be a bit more flexible,
because the real servers don't need to be behind the linux director. It
is also arguably able to provide more throughput as return packets do
not go through the linux director. But you need to watch out for the
ARP problem which is extensively documented in the LVS-HOWTO.
--
Horms
|
