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Red Hat name caching

Got a question about Linux name caching today. Some servers are requesting the same hostname to the DNS server every 2 seconds...
Looked into it and the name caching daemon is not running. Got all the answers I needed here: alt.os.linux.redhat: Re: DNS cache on a RH9 system?. Also found a separate package called dnscache. And a HOWTO for bind to create a local DNS cache on your workstation or server. Simply starting nscd and editing nscd.conf seems sufficient for me now.

BTW, here is my updated /etc/nscd.conf. If anyone has more pointers, please comment.

logfile        /var/log/nscd.log
# use 1-10 for more verbose debugging into log
debug-level    0
# 3 minimum, 5 default
filethreads    5
# 32 is default
max-threads    32
# restart intervals may fail if non-root
server-user    nscd
# user granted to check nscd stats using 'nscd -g'
stat-user      nagios
# 5 is default
reload-count   5 
# restart periodically
paranoia       yes
# restart every 4 hrs, default is 1 hour
#restart-interval  14400 

enable-cache   passwd   no
enable-cache   group    no

enable-cache   hosts    yes
# default in sec; prune hits after this long
positive-time-to-live   hosts 3600 
# default in sec; prune misses after this long
negative-time-to-live   hosts 20 
# entries in hash table, default 211, must be prime!
suggested-size hosts    211  
check-files    hosts    yes
persistent     hosts    yes
shared         hosts    yes
# 16 MiB in bytes
#max-db-size    hosts    16777216

Update: one more important thing, the suggested-size is the size of the hash table. Hashing works well if your table is sparsely populated. I.e. your table should be larger than the actual number of entries it will have. So if you're caching 20 web server on the intranet, the default is fine. If you are caching 3000 IMAP userids and password (see this example), it needs to be a large prime number about 5-10 larger than the 3000 userids.
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