YPSERV
Brett Lee
=============================================================================


One master and many secondaries.

1.  Make your changes on the master.  Then update the NIS maps.
    Usually this done with /var/yp/make, but if you have more than one domain,
    its slightly more complex (and you're probably not reading this... :)

2.  So, the make command remade the maps.  Now, any ypbind client that is
    bound to this servers ypserv has the new maps.

    But, what if you have secondary ypserv's, and clients bound to them?
    Gotta get those new maps over to them.  How?

    Well, on the master, you could run a "yppush" and give the new
    map names:

    # yppush group.bygid group.byname

    Does that work?  What does it do?  Why doesn't the "make" just do it?

3.  Does that work?
    Yes, but not like you may expect.

    What does it do?
    It compiles a list of secondary ypserver's that have that map,
    and contacts them, telling them to pull (ypxfr) the new maps.

    Why doesn't the "make" just do it?
    Well, you might not want to transfer the maps to all the secondaries every
    time you rebuild.
    "grep NOPUSH /var/yp/Makefile" to see what your default is.

4.  So, I ran yppush, and the maps didn't transfer.

    For the maps to transfer, the other end has to request (ypxfr) them.
    Is ypxfrd running on the other end?

5.  What a pain.  Can't I just setup a cron job to pull the maps every so
    often?

    Sure, in fact they are already there.
    ls /usr/lib/yp/ypxfr_*
    Of course, these are shell scripts that have a variable "MAPS_TO_GET"
    that you may need to massage.