> Hi,
>
> > server: Udp: InDatagrams NoPorts InErrors OutDatagrams
> > Udp: 1000665 41 0 1000666
> > clients: Udp: InDatagrams NoPorts InErrors OutDatagrams
> > Udp: 200403 0 0 200406
> > (all clients the same)
>
> How about IP datagrams? You can see the IP fields in /proc/net/snmp
> IP layer may also discard them.
Server:
Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams
InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes
ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates
Ip: 1 64 4088714 0 0 720 0 0 4086393 12233109 2 0 0 0 0 0 0 0 6000000
A Client:
Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams
InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes
ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates
Ip: 2 64 2115252 0 0 0 0 0 1115244 646510 0 0 0 1200000 200008 0 0 0 0
Andrew Theurer
Hi,
> > How about IP datagrams? You can see the IP fields in /proc/net/snmp
> > IP layer may also discard them.
>
> Server:
>
> Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams
> InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes
> ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates
> Ip: 1 64 4088714 0 0 720 0 0 4086393 12233109 2 0 0 0 0 0 0 0 6000000
>
> A Client:
>
> Ip: Forwarding DefaultTTL InReceives InHdrErrors InAddrErrors ForwDatagrams
> InUnknownProtos InDiscards InDelivers OutRequests OutDiscards OutNoRoutes
> ReasmTimeout ReasmReqds ReasmOKs ReasmFails FragOKs FragFails FragCreates
> Ip: 2 64 2115252 0 0 0 0 0 1115244 646510 0 0 0 1200000 200008 0 0 0 0
It looks fine.
Hmmm.... What version of linux do you use?
Congestion avoidance mechanism of NFS clients might cause this situation.
I think the congestion window size is not enough for high end machines.
You can make the window be larger as a test.
>>>>> " " == Hirokazu Takahashi <[email protected]> writes:
> Congestion avoidance mechanism of NFS clients might cause this
> situation. I think the congestion window size is not enough
> for high end machines. You can make the window be larger as a
> test.
The congestion avoidance window is supposed to adapt to the bandwidth
that is available. Turn congestion avoidance off if you like, but my
experience is that doing so tends to seriously degrade performance as
the number of timeouts + resends skyrockets.
Cheers,
Trond
Hello,
> > Congestion avoidance mechanism of NFS clients might cause this
> > situation. I think the congestion window size is not enough
> > for high end machines. You can make the window be larger as a
> > test.
>
> The congestion avoidance window is supposed to adapt to the bandwidth
> that is available. Turn congestion avoidance off if you like, but my
> experience is that doing so tends to seriously degrade performance as
> the number of timeouts + resends skyrockets.
Yes, you must be right.
But I guess Andrew may use a great machine so that the transfer rate
has exeeded the maximum size of the congestion avoidance window.
Can we determin preferable maximum window size dynamically?
Thank you,
Hirokazu Takahashi.