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----- Original Message -----
From: "Wensong Zhang" <wensong@xxxxxxxxxxxx>
To: <lvs-users@xxxxxxxxxxxxxxxxxxxxxx>
Sent: Tuesday, April 23, 2002 11:02 PM
Subject: Re: DRWS-a layer 7 load balancer
>
>
> Hello,
>
> On Mon, 15 Apr 2002, motse wrote:
>
> > Yes. At real server have another kernel module that can rebuild
the
> > connection base on the packet that contains URLs. The DRWS-filter is
the
> > module at real server. You can see the mechanism in the slides.
> >
>
> I just read the slides and some of your code.
>
> I see that there may be some problems in your method, for example, there
> is a long HTTP request which is sent through two packets, how can it be
> handled in your method? Maybe I miss something.
if two packets,the first packet will redirect by it's header. The
second packet or any following packets, I redirect them to the same real
server.
>
> The other problem is that when there are more servers (e.g. 4), in most
> cases, the director cannot forward the request to the right server
("guess
> right"), then the director send RST to the former server. It will bring
> more overhead to both the director and the real servers.
When the pcket filter at the real server receives the RST packet, it
will not send the RST packet to the kernel. It is just a signal to tell
the
packet filter "the connection has moved to another real server", and the
real server will keep silent. But, after 10~15 sceonds, no other requests
come to this real server using the same connection. The pakcet filter must
close the connection.
Ping Tsai
>
> For a high-performance Layer-7 switching, maybe it can be constructured
as
> one IPVS and many KTCPVS (that can be running as real servers, just like
> that you install filter modules on real servers).
>
> Regards,
>
> Wensong
>
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