Hi Cliff Please see inline Il giorno 28/apr/2013, alle ore 18:06, Cliff Burdick <[email protected]> ha scritto:
> Hi, we have a fairly simple requirement for capturing packets, and I'm trying > to figure out the most efficient way to do this. Our setup is as follows: > > - Intel 82598, Xeon 6-core 2.2GHz (12 with hyperthreading), and 32GB of RAM > - Traffic coming from up to 12 known IPs, that have a single thread for each > IP to do parse and analyze the packets > - Aggregate of up to 2Gbps of traffic > > Previously we were using libpcap with pf_ring in transparent mode 1, and it > seemed to be dropping packets. Alfredo suggested we switch to DNA clustering, > so we're in the process of doing that. However, I have a couple of questions: > > 1) It appears that in the DNA load script it's suggested that RSS is > completely turned off in the intel driver so that the master cluster thread > can do something similar. Since RSS is done in hardware, won't this have a > performance impact? No, specially at 2 gbit. However, if you need a simple IP-based balancing, hw RSS is also an option (but please note that you don t have full control on the hash function). > > 2) The master would be a single thread whose only job is to pull a packet > from the one RX queue on the card, run through the custom hash function, and > forward the packet using zero-copy to one of the twelve threads. Will one > core be sufficient enough for a single thread to hash every incoming packet? Yes > > 3) In this paper: > > http://luca.ntop.org/imc2010.pdf > > it is recommended to have the "capture thread" and "polling thread" on a > single core so that they can share the same cache. In my case the master > cluster would be the "capture thread" (which there is only 1?), and the > "polling thread" will be one of the other 12 that capture/analyze data from > the unique IPs. Since we only have a 6-core processor (12 with HT), what is > the recommended way of distributing the 12 poller threads to minimize cache > coherency issues? Since the DNA master is using one part of the core, we > would have to share the rest of them somehow, so I wasn't sure if the answer > was to have multiple DNA cluster masters. This paper describes the kernel-space cluster, those considerations do not apply to the Libzero DNA Cluster. For fine tuning cpu affinity have a look at the load on the cores with your traffic and processing applications. Best Regards Alfredo > > Any suggestions would be appreciated. Thanks. > _______________________________________________ > Ntop-misc mailing list > [email protected] > http://listgateway.unipi.it/mailman/listinfo/ntop-misc
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