Condor <[email protected]> wrote: > Hello ppl, > do I can ask what traffic from pool is normal ? I have some times > problems ... I think I got too much query. This problem is from long time > and it's happened only for small amount of time. For 30 min to 1 hour and > usual when Im not logged in to see what's happened. Here is error that i > got from kernel:
> net_ratelimit: 686 callbacks suppressed > nf_conntrack: table full, dropping packet. > nf_conntrack: table full, dropping packet. > nf_conntrack: table full, dropping packet. > I use some optimization on tcp/ip network like: > # increase TCP max buffer size setable using setsockopt() > # 16 MB with a few parallel streams is recommended for most 10G paths > # 32 MB might be needed for some very long end-to-end 10G or 40G paths > net.core.rmem_max = 16777216 > net.core.wmem_max = 16777216 > # increase default values > net.core.rmem_default = 16777216 > net.core.wmem_default = 16777216 > # increase Linux autotuning TCP buffer limits > # min, default, and max number of bytes to use > # (only change the 3rd value, and make it 16 MB or more) > net.ipv4.tcp_rmem = 4096 87380 16777216 > net.ipv4.tcp_wmem = 4096 65536 16777216 > # recommended to increase this for 10G NICS > net.core.netdev_max_backlog = 10000 > net.ipv6.conf.all.forwarding = 1 > net.netfilter.nf_conntrack_tcp_timeout_established = 2000 > net.ipv4.netfilter.ip_conntrack_tcp_timeout_established = 2000 Sigh - as pointed-out, none of that tcp nonsense applies to NTP. And frankly, even for TCP, a 16 MB net.core.[rw]mem_max or tcp_[rw]mem is pointless. It was (I suspect) merely shotgunning by 10 GbE NIC vendors. I will leave the math involving: Throughput <= WindowSize/RoundTripTime as an exercise for the reader, but unless one has a non-trivial latency in their 10GbE LAN, 1MB or so should be more than sufficient for "link-rate" TCP. So, one might consider tweaking net.core.[rw]mem_max to 1048576 or 2X that. And, as the default (most of the time anyway) upper bound on tcp_[rw}mem is already 4MB that does not need to be changed. I dont think I've ever changed netdev_max_backlog in any of my netperf testing over 10GbE. rick jones -- Process shall set you free from the need for rational thought. these opinions are mine, all mine; HP might not want them anyway... :) feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH... _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
