Messages in this thread | | | Date | Wed, 9 Nov 2011 00:42:31 -0800 (PST) | From | Manavalan Krishnan <> | Subject | Re: Large file copy to NFS mounted directory causes delay in other application packets |
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>When I see behavior like this I keep thinking interactions between overlarge large txqueuelens, somewhat busted TCP offloads on NICs, and that pfifo_fast must die in favor of fair queuing and/or diffserv classification. But seeing >it on two different nics implies that your switch (which I assume is shared) is possibly to blame... >(I see bufferbloat everywhere, but mostly because it's what I work on)
>Is this NFS over TCP? Does the HA daemons prioritize packets at all? Does your switch? Does your qdiscs? How deep are your buffers on the network cards and txqueuelens and switch? >(eric's other questions below are probably more valid)
HA daemons does not prioritize. could you please provide info on how to prioritize application packets? We tried with different switches, the same problem occurs. so switch may not be the issue here. switch and qdisks does not prirotize the packets. Here are network buffers used in the servers
txqueuelen is 1000
net.core.netdev_max_backlog = 1000 net.core.rmem_default = 262144 net.core.rmem_max = 262144 net.core.wmem_default = 129024 net.core.wmem_max = 131071 net.ipv4.tcp_rmem = 4096 87380 4194304 net.ipv4.tcp_wmem = 4096 16384 4194304 net.ipv4.tcp_mem = 196608 262144 393216
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