Is the FreeBSD system using accf_dns (ACCEPT_FILTER_DNS) ? If so, perhaps something like it is needed on RHEL?
On 04/25/14 11:51, Shawn Zhou wrote: > > Looks like BIND 9.9.4b1 has support for SO_REUSEPORT as test results I get > from RHEL 6.5 look better than what I have from RHEL 6.4: > > https://www.dropbox.com/s/4u1ajqoj16ar7tl/40MB_receive_buffer.png > > I have been wondering why the drop rate is higher in the lower range of QPS in > FreeBSD (24 UDP BIND listeners) than RHEL 6.5 (16 UDP BIND listeners). Could > it be that those 24 listeners are handing out queries too fast from the socket > to worker threads on FreeBSD and those 16 listeners are emptying the receive > queue at the right speed for worker threads until we hit the peak at ~200k QPS > on RHEL6.5? > > My tests show 16 listeners on RHEL 6.4/6.5 provides the best performance on > hosts with 24 and 40 CPU threads. I am not sure why 16 is such a magic number > ("Sweet 16", I guess). > > Look at 9.10.0b2 release > notes https://kb.isc.org/article/AA-01142/81/BIND-9.10.0b2-Release-Notes.html, > ISC will be adjusting the default setting for the number of listeners: > > * The default setting for the -U option (setting the number of UDP listeners > per interface) has been adjusted to improve performance. [RT #35417] > > > Anyone knows what logic will be used? > On Thursday, April 24, 2014 5:51 AM, Ralf Weber <[email protected]> wrote: > > Moin! > > On 23 Apr 2014, at 22:09, Jared Mauch <[email protected] > <mailto:[email protected]>> wrote: > > Despite using RHEL 6.4, I wonder if 6.5 or hand-building a 3.x series > kernel might provide benefits not evident in the 2.6.3x series that RHEL > ships. > RHEL 6.5 has a kernel with SO_REUSEPORT support. which can improve UDP > performance, but AFAIK needs support from the DNS server software. Not > sure if bind supports that. Then of course you could use another DNS > software. > > So long > -Ralf > > > > > _______________________________________________ > dns-operations mailing list > [email protected] > https://lists.dns-oarc.net/mailman/listinfo/dns-operations > dns-jobs mailing list > https://lists.dns-oarc.net/mailman/listinfo/dns-jobs > -- Who: Lawrence K. Chen, P.Eng. - W0LKC - Sr. Unix Systems Administrator For: Enterprise Server Technologies (EST) -- & SafeZone Ally _______________________________________________ dns-operations mailing list [email protected] https://lists.dns-oarc.net/mailman/listinfo/dns-operations dns-jobs mailing list https://lists.dns-oarc.net/mailman/listinfo/dns-jobs
