ACC SHELL

Email conversation on 2001-08-08 between
Thorsten Kukuk <kukuk@suse.de>, ypbind maintainer
Martin Vidner <mvidner@suse.cz>, yast2-config-nis maintainer

kukuk:
SuSEconfig should not set the domainname. This is done at boottime
(the only place where it is really safe to set it) and in
/etc/init.d/ypbind, if it is not already set. Changing the domainname at
runtime is as bad as changing the hostname with running X11.

mvidner:
I have thought a bit more about this. If I change the NIS domain, I should
naturally take care that the old and new maps are consistent, eg. uids and
usernames, passwords...

But it does not matter when the switch happens, does it? What will break
if I change yp.conf, domainname and restart ypbind?

kukuk:
The problem is: a program caches at first his domainname and uses this,
independent if you change the domainname or not. So, if you change
the domainname, all already running programs will continue using
the old one. If you restart ypbind with a new domainname, all already
running programs will fail to lookup anything over NIS because ypbind
does not know any longer the data for the old domainname.

mvidner:
In the future, can this be fixed? I assume that the cache is somewhere in
libc. Or perhaps in nscd. Otherwise if any program just caches
configuration data and refuses to reload it, then the program should be
fixed.

kukuk:
No, this is the design Sun made about 12 years ago. This will not be
changed. One reason is, that getdomainname() is a syscall, and syscalls
are very expensive.
I will not change common, well known behaviour. All Unix behave so.