[CentOS] Odd issue with C6 and NIS

Thu Oct 6 23:10:24 UTC 2011
Stephen Harris <lists at spuddy.org>

On Thu, Oct 06, 2011 at 11:47:21PM +0100, John Hodrien wrote:
> On Thu, 6 Oct 2011, Stephen Harris wrote:
> > I wouldn't do that in NIS.  Why would my OS care about it?.  But I would
> > do "tell me the path to the latest version of application X" 100s of times
> > per minute.
> Which should all be cached at the client side.

You're missing the point.  If the query was sufficiently fast then you
don't _need_ to worry about caching, and thus cache coherency, speed of
propagation of changes, inconsistent results between machines etc etc.

Caching is a _kludge_ to hide an underlying problem.  It adds complexity
and additional failure modes.

LDAP is slow.  nscd, sssd, ldapcachemgr et al are all klduges to work
around that fact.

And the whole world isn't nss.

The reality is that we're screwed; LDAP became the God Of Naming Services and
everybody rushed into it (didn't help that Sun's NIS+ was just plain bloody
awful).  And so we're paying the price; caching has become essential.

We (where I work) moved into LDAP a decade ago.  And it's only now that the
OS performance is beginning to approach that of a NIS client.