Bind 9.10.3 on CentOS 7.1 - Recv-q on vmware

[Mukund Sivaraman]

Hi Rasmus

On Tue, Dec 15, 2015 at 03:20:05PM +0100, Rasmus Edgar wrote:
> We started noticing 1s+ latency problems on clients resolving using the
> vmware guest at a load around 6000 qps.
> 
> Test setup:
> 
> 1 x x86_64 vmware guest on Esx 5.5
> 8xVCPU
> 8G RAM
> vmxnet3 10Gb virtual interface
> CentOS 7.1
> Bind 9.10.3 resolver
> 
> 1xIBM x86_64 physical machine
> 24xCPU cores
> 16G ram
> 1Gb interface
> CentOS 7.1
> Bind 9.10.3 resolver

Generally VMs are not a proper place to test query performance, but
anyway let's see.  When named starts, it logs messages like this:

15-Dec-2015 20:08:00.245 found 8 CPUs, using 8 worker threads
15-Dec-2015 20:08:00.245 using 7 UDP listeners per interface
15-Dec-2015 20:08:00.245 using up to 4096 sockets

Please will you paste what you get in your configuration?

> ./dnsperf -f inet -s <redacted ip> -d queryfile-example-10million-201202 -l
> 30 -q 15000

Why are you passing the -q argument to dnsperf?

A high receive queue means your named process is not able to read off
the socket fast enough. Try to find out where it's busy, using a
profiler such as perf. Is it query logging or doing some other highly
verbose logging that keeps it blocked in disk IO?

		Mukund
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <https://lists.isc.org/pipermail/bind-users/attachments/20151216/9906288b/attachment.bin>