[nsd-users] NSD 4.5.0rc1 pre-release

[A. Schulze]

Wouter Wijngaards:

> I managed to run the regression test suite for NSD on libev. Two
> different versions of it, but it does not produce that failure.
> Everything works, apart from a signal handling test that fails, but
> downloading an axfr does not involve signal handling, so that is not the
> issue here.
>
> Not sure how to proceed, since I cannot reproduce. I wonder what the
> cause is.

Hello Wouter,

thanks for having a look into my trouble. I wonder about your "could  
not reproduce"
Did you build both containers with the Dockerfiles I send?

I've two servers receiving AXFF from a BIND master (no version known)
where I see the segfault messages constantly after AXFR.
I also could not reproduce any segfault on AXFR in a lab. I tried  
NSD-provider -> AXFR -> NSD-consumer
and used even the same zone. That makes the segfaults something strage  
to me, too.
They really did only happen on my prod servers.
Using the Dockerfiles was the first time I could trigger a similar error
but yes, the setup is not the same.

I now switched on server to a version built with libevent instead of libev
and the segfaults no longer happen!

In both cases the error happen very late when a process terminate.
So maybe it's related.

I plan to replace libev by libevent on /all/ of my numerous NSD instances.
That would solve this issues for me.

Could you describe the differences between libevent and libev?
What was the reason you implemented NSD in a way to use one OR the  
other library?
What may I expect when switching from libev back to libevent?
More load? Latency? Memory usage? Watever?

Andreas