Very bad distribution of packets between multiple listening threads

[K. Macy]

On Wed, Feb 15, 2012 at 11:17 AM, Attila Nagy <bra at fsn.hu> wrote:
> Hi,
>
> I'm using FreeBSD 9-STABLE on a four core machine with bce to run
> multi-threaded unbound with libev (using kqueue).
> Here's the first message (not a long thread so far) about the problem:
> http://unbound.net/pipermail/unbound-users/2012-February/002237.html
>
> To summarize:
> whether I run unbound in multi-threaded or multi-process mode, I get very
> bad DNS query distribution between threads/processes.
>
> There is sometimes a 10-fold difference in the queries served (QPS) between
> threads (for example thread X gets 300, thread Y gets 3000).
>
> What could be done to make this distribution more balanced between threads?
> And where does this happens exactly?
>

I don't have a fix for this problem, but I can comment that an ISP I
know of switched away from using kqueue with lighttpd to poll because
the load was not well distributed.
Cheers