max-cache-size doesn't work with 9.5.0b1

[JINMEI Tatuya / 神明達哉]

At Tue, 29 Jan 2008 11:40:39 +0100,
Attila Nagy <bra at fsn.hu> wrote:

> >> Without threading I don't see this effect, the memory usage stops at a 
> >> sane limit and it's size can be affected by setting the max-cache-size 
> >> option.
> >>
> >> I don't think you would gain anything usable with that, am I right?
> >
> > Right.  Can you try a simpler patch that focuses on the memory usage
> > status and works with threads?  If so, I'll write one and send it to
> > you.
> >   
> Of course. The machines are diskless, so writing larger log files 
> directly is not an easy task. (syslog is ok)

Okay, please use the attached patch (applicable to 9.5.0b1, and also
to 9.5.0b2 when it's published).  Build it with:
% STD_CDEFINES='-DLRU_DEBUG2=2' ./configure --enable-threads
(or set STD_CDEFINES using setenv if you use a csh variant)

The log messages shouldn't be very noisy, but if you find them too
frequent, rebuild it with:
% STD_CDEFINES='-DLRU_DEBUG2=1' ./configure --enable-threads

Note that, if this is a thread-related bug, it may not always be
reproduceable; please try several times if the problem doesn't seem to
happen.  (BTW: did it always occur when you first found the problem?)

> ps: I have an other problem. I've recently switched from a last year 
> 6-STABLE to 7-STABLE and got pretty bad results on the same machine with 
> the same bind (9.4).
> The graphs are here:
> http://picasaweb.google.com/nagy.attila/20080129Fbsd6vs7Bind
> 
> The interesting part (from when the comments are valid) starts at around 
> the half of the picture. You can see that on FreeBSD 6, the CPU load is 
> pretty much good, but on 7, both the userspace and the kernelspace 
> activity grows significantly.

I have no idea about why this happened at the moment.  Do both server
handle the same level of query rate?  (I'm also curious what happened
in the first half of the graphs for both cases).

> I've used libthr on 6, and it is the default on 7 too. bind is threaded.
> I use ISC_INTERNAL_MALLOC, but the effect is the same without it.

This shouldn't matter because ISC_INTERNAL_MALLOC is enabled by
default as of 9.4.

Thanks,

---
JINMEI, Tatuya
Internet Systems Consortium, Inc.