Original question:
I am currently attempting (!) to look at the performance of our web server
and mailhub (2 separate systems). Both systems run a caching-only DNS
(named). The mailhub runs exim software; the web server Apache and Squid for
web-caching. Our nsswitch.conf file states 'hosts: dns files'. I saw on the
Squid web site a note that stated that the nscd process could run very slow
when the DNS resolver was heavily used - as with the web server. It was
recommended to configure it not to cache host names. I have 2 questions
though:
1) Is this true; does the nscd run slow (just inefficient?) ?
2) Is it better to run named (as a caching-DNS) rather than nscd to cache
the host entries, or is nscd better despite the above? (We also
currently cache DNS lookups with Squid - I am assuming that there
is no need for this if we're running named to cache the entries?)
I received (I think) 3 replies which stated that basically nscd was not very
good, and indeed could cause problems under certain circumstances. Running
named should be all that's needed, and this we now do. (Having upgraded my
mail client I lost the actual replies I received - sorry!)
John.
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John Horne E-mail: J.Horne@plymouth.ac.uk
Computing Service Phone : +44 (0) 1752 - 233911
University of Plymouth, UK Fax : +44 (0) 1752 - 233919