KDE + LDAP = snail speed
 

I recently got a new work machine (3 GHz Pentium), which is on an
IPSec network, with the default setup to use LDAP.
The distrubution is SuSE 9 (with KDE 3.1) + official updates.

Besides LDAP being used for username + password lookups,
it seems to be also used for hostname lookups.

Running GNOME is no problem, though I prefer KDE.
Problem is, KDE was about as fast as a snail on a good day;
for example, changing small folders in KMail took at least 20 seconds.
( localhost and the name of the local machine were already in /etc/hosts )

The solution was to disable LDAP via SuSE's Yast2 configurator.
KDE flies like a demon now.

So the question is: why does LDAP slow things down so much ?

OR, alternatively,

if the problem is not with LDAP, it means that KDE is looking up
hostnames and/or usernames all the time. How does one disable
this default behavior ? is this a bug ?

LDAP is pretty fast. Open LDAP uses the ldap.conf in /etc/openldap/ldap.conf. PAM uses /etc/ldap.conf. Check your settings there.

What happens when you do a "finger" to the user stored on ldap?


The file /etc/nsswitch.conf controls is file is used or ldap or .. etc etc. On redhat "authconfig" is used to enable/disable ldap. ALternatively you can edit the files yourself.

Another thing to check is the pam config "/etc/pam.d/system_auth"


What happens when you use the ldap util "ldapsearch".

it takes between 5 to 10 seconds to respond


Wherever possible, the first option was "files", followed by "dns" or "db" etc.
example:

passwd: files
group: files
hosts: files dns

if the dns option was removed, everything started to work real quick (while LDAP was enabled)
but looking up hostnames didn't work. this is strange, as the /etc/hosts file had the entries for
the hosts I was looking up.
(this leads me to believe that the slowdown problem with KDE
has more to do with looking up hostnames rather than usernames/passwords).

i've noticed that /etc/nsswitch.files also exists, though it has everything set to "files",
except for "hosts", which is the same as for /etc/nsswitch.conf.

this file doesn't seem to exist on SuSE linux 9. there are plenty of other files,
but none of them mention "ldap".