Re: Poor Performance for ethernet bonding

[Ben Greear <greearb@candelatech.com>]

Andi Kleen wrote:
> 
> Bernhard Busch <bbusch@biochem.mpg.de> writes:
> 
> > Hi
> >
> >
> > I have tried to use ethernet  network interfaces bonding to increase
> > peformance.
> >
> > Bonding is working fine, but the performance is rather poor.
> > FTP between 2 machines ( kernel 2.4.4 and 4 port DLink 100Mbit ethernet
> > card)
> > results in a transfer rate of 3MB/s).
> >
> > Any Hints?
> 
> Bonding reorders packets, which causes frequent retransmits and stalls in TCP.
> One setup that doesn't is multipath routing (ip route .. with multiple
> nexthops over different interfaces). It'll only load balance (srcip, dstip,tos)
> tuples though, not individual flows, but then it has the advantage that
> it actually works.

Couldn't the bonding code be made to distribute pkts to one interface or
another based on a hash of the sending IP port or something?  Seems like that
would fix the reordering problem for IP packets....  It wouldn't help for
a single stream, but I'm guessing the real world problem involves many streams,
which on average should hash such that the load is balanced...

Ben

> 
> -Andi
> -
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-- 
Ben Greear <greearb@candelatech.com>          <Ben_Greear@excite.com>
President of Candela Technologies Inc      http://www.candelatech.com
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