nscd (was: Re: Kernel Crash with FC3 [glibc?])

[Pekka Pietikainen]

On Tue, Jan 11, 2005 at 12:49:18PM -0800, Ulrich Drepper wrote:
> We had a few people reporting problems but nobody ever was able or 
> willing to provide any data.  I use it on all my machines and never had 
> problems.
> 
> So, if the problem is reproducible after
> 
>  service nscd restart
> 
> then stop it again, and start nscd by hand with
> 
>   /usr/sbin/nscd -d -d -d
> 
> After this perform the operation which fails and send the output (or 
> better yet, create a bug).
Returning to an old issue :) 
We've been seeing nscd cache expiration problems every now and then
like I mentioned a few months back with both passwd and hosts. Has
happened often enough that it's not just a local configuration issue

It seems like positive hits just don't time out, and nscd -i is the only
thing that clears things up. passwd/hosts "never" get touched (we're using
NIS+, customized local install), so the entries don't get invalidated that
way, which might be the reason not that many other people are seeing the
same problem. Another symptom I've sometimes seen is a DDNS host 
have an old address for days (until nscd -i hosts). nslookup,
which doesn't go through nscd, shows the current address.
nscd is running with default timeouts (600 secs for passwd, 3600 for hosts)

Will be happy to get data to track this down. I suppose there's no
database dumper that would tell what nscd is actually currently caching and
how old the data is? 

I've actually ran nscd for quite some time in debug mode, and the only
situation it flushes entries is touch /etc/passwd and touch /etc/hosts.

Ah, there's a bugzilla #150748 about the same issue. Added some comments
there too.

-- 
Pekka Pietikainen