multiple namespaces

[Barry Margolin <barmar@think.com>]

    Date: Fri, 26 Jun 87 17:47 EDT
    From: Chris Lindblad <CJL@reagan.ai.mit.edu>

	Date: 26 June 1987 1056-PDT (Friday)
	From: stanonik@nprdc.arpa

	Sorry if this (undoubtably) has come up before.

	We have two groups (call them red and blue) of machines,
	each group in its own namespace.  (Why not one namespace?
	To protect each group against misadventures in the namespace
	of the other.)  The red machines need to occasionally access
	the blue machines.

	Simple add blue to the searchlist attribute of red's namespace
	object.  Catch-22.  red doesn't have a namespace object for
	blue.  Well, add one.  Gotcha!  red doesn't have a host object
	for blue's server.  Well, add one first, blue|server.  Heh heh!
	red doesn't have a namespace object for blue.  Sounds like zen,
	if you have to ask, don't ask.

    Starting off on the namespace server for the red namespace, with it currently
    only knowing about the red namespace (no references to blue anywhere).
    (Essentially the state right after doing the :Set Site command from a
    distribution world)

    Do a (neti:find-site :blue), and answer the questions. The machine will now
    know about the blue namespace.

    Edit the namespace objects for the network red|chaos, and add a nickname
    blue|chaos. This tells the namespace system that the chaos network mentioned
    in the red namespace is the same chaos network mentioned in the blue
    namespace. 

    If you use tcp-ip, do the same for the network red|internet.

Actually, it's even easier than that, assuming you are running at least
Genera 7.0.  All you have to do is

	(neti:find-site :blue :link-to-old-site t)

The :link-to-old-site option causes the networks of the two sites to be
made synonyms of each other.  If you do it manually, it sometimes loses
because of order dependencies; the automatic mechanism generally does it
right.

    Add blue namespace to the search path for the red namespace.

    Reboot the distribution world load on the namespace server for red, do a "Set
    Site" command to the red site, and answer the questions. After the set site,
    you can disk save the world.

    Namespace can work well if configured well. Here at MIT we have 8 separate
    sites, 7 different namespaces, 3 different primary servers, 2 of which
    secondary serve each other, and another machine just being a secondary
    namespace server. All this to service about 120 Lisp Machines around campus.