[Pdns-users] pdns_recursor stops getting queries on Solaris 10 sparc

[Jan Gyselinck]

On Wed, Sep 12, 2007 at 03:22:32PM +0200, Christian Kuehn wrote:
> Alex Kiernan wrote:
> > I ran into this problem on a live box, so I ended up backing out and
> > going back to bind, but I've grabbed a set of queries which reproduce
> > the problem (eventually).
> > 
> > When it stops doing stuff it, it looks like its not getting new queries:
> > 
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > port_getn(7, 0x0012D108, 1024, 1, 0xFFBEF44C)   = 0 [62]
> > 
> > But it seems like it only happens after ~250K queries. I'm pushing my
> > queries at it using UDP (using perl ParaDNS), once it has given up,
> > its only the UDP queries which break - TCP still works.
> > 
> > Any pointers where to start looking?
> > 
> HI,
> 
> we found the same problem and it looks like a problem with Sol10.
> 
> Our fix was a small change in sysdeps/SunOS.inc
> 
> ifeq ($(CC),cc)
>         CC:=gcc
> endif
> 
> LDFLAGS+=-lresolv -lsocket -lnsl
> OS_SPECIFIC_INSTALL=mkdir -p $(DESTDIR)/etc/init.d ; cp pdns-recursor.init.d $(D
> ESTDIR)/etc/init.d/pdns-recursor
> 
> #OPTIONALS:=optional/portsmplexer.o
> 
> #optional/portsmplexer.o: portsmplexer.cc
> #       $(CXX) $(CXXFLAGS) -c $< -o $@  ; true
> 
> 
> Good luck!
> 
> Cheers
> Christian
>
> -- 
> Christian K?hn
> (Technical Consultant / Hostmaster)
*snip*
 
 
Surely you have a much higher overhead to handle the same number of queries now?
Sun still has no Intel/AMD equivalent cpu's when comparing raw computing power
in their SPARC gamma so every bit of juice you can squeeze out of it helps.

Hint:
When using the sun4u platform, except for US-III 750 Mhz cpu's, you can
use 4 MB pages for the recursor by using this command to start it:

ppgsz -o heap=4M,anon=4M /usr/local/sbin/pdns_recursor

(verify with: 'pmap -xs <pid>')

This improves performance with something around 3% for a resolver with 800 MB,
depending on your situation this may be less or even more.  When using the
portsmplexer it could make the problem appear less often.


Jan Gyselinck