Rhel 5.6 increasing bind qps

[Greaser, Tom]

Hello all. 
I just wanted to pass on some testing we have done to increase our qps when running  dnsperf with all dns queries being auth zoned by our bind boxes.   
I was tired of seeing postings on line about some boxes getting 100k qps and knew ours could do better than what it currently was getting
Now to be 100% here please read all man pages before mucking with kernel ip stack settings..

My client is Fedora 14 64 (no modified ip stack settings)
dnsperf-1.0.1.0-21.fc14.x86_64

Named Server System  info  (server dose other things too)
8gig ram
Two  Dual-Core AMD Opteron(tm) Processor 2220
Running 
2.6.18-238.9.1.el5 #1 SMP Fri Mar 18 12:42:39 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
Red Hat Enterprise Linux Server release 5.6 (Tikanga)
bind-utils-9.3.6-16.P1.el5
bind-chroot-9.3.6-16.P1.el5
bind-libs-9.3.6-16.P1.el5
bind-9.3.6-16.P1.el5


Statistics:
  Parse input file:     multiple times
  Run time limit:       60 seconds
  Ran through file:     81 times
  Queries sent:         1678416 queries
  Queries completed:    1678361 queries
  Queries lost:         55 queries
  Avg request size:     40 bytes
  Avg response size:    79 bytes
  Percentage completed: 100.00%
  Percentage lost:        0.00%

  Started at:           Wed May 25 09:29:49 2011
  Finished at:          Wed May 25 09:30:49 2011
  Ran for:              60.000398 seconds

  Queries per second:   27972.497782 qps

then modified 
echo 26214400 > wmem_max 
echo 26214400 > rmem_max 
Statistics:
  Parse input file:     multiple times
  Run time limit:       60 seconds
  Ran through file:     129 times
  Queries sent:         2654557 queries
  Queries completed:    2654538 queries
  Queries lost:         19 queries
  Avg request size:     40 bytes
  Avg response size:    79 bytes
  Percentage completed: 100.00%
  Percentage lost:        0.00%

  Started at:           Wed May 25 09:34:36 2011
  Finished at:          Wed May 25 09:35:36 2011
  Ran for:              60.000328 seconds

  Queries per second:   44242.058143 qps


then modified
 echo 65536  > udp_rmem_min 
 echo 65536  > udp_wmem_min 
Statistics:

  Parse input file:     multiple times
  Run time limit:       60 seconds
  Ran through file:     136 times
  Queries sent:         2797867 queries
  Queries completed:    2797859 queries
  Queries lost:         8 queries
  Avg request size:     40 bytes
  Avg response size:    79 bytes
  Percentage completed: 100.00%
  Percentage lost:        0.00%

  Started at:           Wed May 25 09:38:03 2011
  Finished at:          Wed May 25 09:39:03 2011
  Ran for:              60.000472 seconds

  Queries per second:   46630.616506 qps


 echo 100 > max_dgram_qlen
Statistics:

  Parse input file:     multiple times
  Run time limit:       60 seconds
  Ran through file:     146 times
  Queries sent:         3008730 queries
  Queries completed:    3008730 queries
  Queries lost:         0 queries
  Avg request size:     40 bytes
  Avg response size:    79 bytes
  Percentage completed: 100.00%
  Percentage lost:        0.00%

  Started at:           Wed May 25 09:41:50 2011
  Finished at:          Wed May 25 09:42:50 2011
  Ran for:              60.000304 seconds

  Queries per second:   50145.245931 qps