[Kroupware] FAQ: flexible administration of multiple kolab servers

[Paul de Vrieze]

On Tuesday 01 October 2002 20:00, Tim Jansen wrote:
>
> Having thought about it... how can DNS help to make it more scalable? D=
NS
> does not scale because the DNS servers have the fastest databases on ea=
rth
> and the protocol is so fast. If you have 20 Million users/hosts in the
> .kde.org domain the DNS server still has to search through all 20 milli=
on
> users/hosts.

Ever heard of hashing tables?
If you need to look up a word in the dictionary you don't start with the =
first=20
word, and read through until you find the word you are interested in. If =
the=20
word starts with a P you start searching somewhere in the middle of the b=
ook=20
and you skip pages as you are gradually going to the word you are looking=
=20
for. Hashing tables work similarly, except that they use something called=
 a=20
hashing function to calculate a hash of the word you are looking for. The=
=20
hash table has a (large) number of buckets in which words are put. The ha=
sh=20
determines in which bucket the system starts to look. This is speed effic=
ient=20
(though memory intensive).

Paul

--=20
Paul de Vrieze
Junior Researcher
Mail: pauldv@cs.kun.nl
Homepage: http://www.devrieze.net