Does anyone use nscd?

David Brodbeck brodbd at
Mon Oct 10 19:19:14 UTC 2011

On Fri, Oct 7, 2011 at 3:30 AM, Michael Bushkov <bushman at> wrote:

> While I agree that nscd negative caching bug should be fixed, it won't
> help with the problem that users encounter during ports installation.
> When, for example, user "x" is added during port install, the
> following steps are involved:
> 1. Script checks if "x" is present in the users list. Nscd is queried,
> it returns negative and caches negative answer.
> 2. Script adds user "x".
> 3. Script checks that "x" have indeed been added. Nscd is queried,
> cachned negative answer is returned. Script fails as a result.
> So unless negative caching time is less than the time between steps 1)
> and 3) the issues during ports installation will persist.

Is there any reason to cache negative hits?  It seems like you shouldn't see
large volumes of them except in some fairly specific circumstances, like
extracting a tarball as the root user with invalid UIDs.  Maybe I'm missing
something, but it seems like turning off negative caching would avoid a lot
of potential problems for not much cost.

David Brodbeck
System Administrator, Linguistics
University of Washington

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