LDAP
From Wikitech
Hosts should be to use LDAP for users and some other stuff.
setup LDAP client on new machine
- run /home/wikipedia/bin/setup-ldap
- copy zwinger:/etc/ldap.conf to the new machine
LDAP server is on srv1 (master) and srv2 (slave). failover should be automatic. to add new users, add them on srv1, then run /home/wikipedia/bin/ldapsync. srv2 will update automatically.
Overload
If the local caching daemon nscd dies on clients, the server can get badly overloaded and logins can fail.
If necessary restart it sitewide. :P
Server logging
slapd's logging stuff goes to a channel on syslog that's not logged by default. On a new server, you may have to manually edit syslog.conf and add something for local4.*
Then set an appropriate loglevel in /etc/openldap/slapd.conf