Some gruesome moments with performance of FreeBSD at over 20K interfaces

[Harti Brandt]

On Wed, 9 Apr 2014, Vladislav Prodan wrote:

VP>b) Service bsnmpd started at 12K interfaces, but immediately loaded CPU 
VP>at 80-100%

I could imagine that this is because of the statistics polling. bsnmp 
implements 64-bit interface statistics but we have only 32-bit statistics 
in the kernel. So it polls the kernel statistics for each interface on a 
rate that ensures that 32-bit don't overflow. If the interfaces are GBit 
or, worse, 10GBit interfaces the polling rate is rather high (in the order 
of seconds).

You should either make sure that the interfaces report sensible bitrates 
(I doubt that 20k interfaces could all be GBit interfaces) or force a slower 
polling interval by setting begemotIfForcePoll.0 to some large value.

harti