[SunRescue] Solaris 8 DNS?

[Devin L. Ganger]

On Thu, May 17, 2001 at 11:06:40PM -0500, William Barnett-Lewis wrote:
 
> Obviously this is a night for learning things. I'll lay myself open for
> laughter perhaps, but I have never heard of negative caching. What I
> would think of as caching - saving data for near future reuse - would be
> positive, yes? So what then is negative? 

I do a hosts lookup for a host that hasn't been added to the naming service
yet.  nscd will cache that negative result (NXDOMAIN is it's DNS, etc.) for
some indeterminate period of time, even though the record could be added
just a few seconds later and subsequent lookups should succeed.

Basically, it's an *extra* level of caching if you're using DNS for host
resolution, one that doesn't do a very good job of honoring the record
TTLs and does weird stuff that isn't standard behavior in DNS resolution.

I personally have never seen crashes and such using nscd, but I've noticed
a hell of a lot more stable and even-tempered DNS behavior on my Solaris
boxes since I learned about that trick.

-- 
Devin L. Ganger <devin at thecabal.org>
find / -name *base* -exec chown us:us {} \;
su -c someone 'export UP_US=thebomb'
for f in great justice ; do sed -e 's/zig//g' < $f ; done