named out of swap on NetBSD/amd64

[Jan Schaumann]

Greg Choules <gregchoules+bindusers at googlemail.com> wrote:

> There could be SO many things going on here. I have a few questions:

All good questions, thanks! :-)

> - Do you mean 200 QPS or 200,000 QPS?

Actually only around 200.  I'm effectively looping
over a list of names and calling res_query(3).

> 200 QPS is background noise and (depending what's going on)
> shouldn't be close to killing a box.

The system itself has no problems at all and remains
responsive; it's just named that gets killed.

> - Are you stuck on 9.16.30 for some reason? If not, grab the latest 9.18
> package. It will be less memory hungry generally and contain fixes for
> recent issues.

Yeah, will give that a try.

> - Can you give the system more memory? Real RAM, not swap. Swap is bad for
> DNS generally because it's so slow.

It's a virtual private server where I don't have
physical access and the RAM allocated is tied to the
subscription / support contract with the provider.

I could pay for more RAM, but haven't had a need so
far...

> - What does your config look like? Do you have lots of views, RPZ, stale
> cache... All those things would tend to increase the memory footprint of a
> busy server, depending on the query pattern.

It's a trivial configuration with just a handful of
zones the server is authoritative for; the primary use
is as a local caching resolver.

> - What sort of queries are you hitting it with?

Right now it's all MX lookups of second-level domains.

> That turned into a bit more than a few! I hope some of that helps a bit.

It does, in that it gives me plenty to do to better
nail down the problem. :-)

Thanks - if I come up with anything, I'll report back.

-Jan