It's Alive

[Barry Margolin <barmar@THINK.COM>]

    Date: Wed, 20 Sep 89 11:23:04 EST
    From: bouma@cs.purdue.edu

	Why is it that when I make changes to the NAMESPACE some of the
    machines don't notice? For instance, one machine on the network went
    away, and we got another (unix machines), so I edited the namespace
    appropriately. But some of the machines still list that deleted machine
    as a dead connection in PEEK on NETWORK? Rebooting does not help, but
    Reset Network gets rid of it until the next time I reboot.
	How is it that all the lisp machines know about the new machine I
    added, but some still think the one I deleted is out there? Is info
    cached in a world file overriding the present namespace? Does this
    behavior conform with the way the namespace works, or it is a local
    bug in our system?

Machines will only query the namespace server about a host if they
believe that it has changed, or if you force them to by using the
:CHECK-VALIDITY message (the Show Namespace Object command does this). 
Deleting a host doesn't seem to count as a change for these purposes.
Therefore, hosts that existed when the band was saved will continue to
exist until you build a new band.

In the case of new machines, whenever you type a host name that the
local host has never heard of, it queries the namespace server.  So, new
hosts always show up immediately.

Normally a Lispm will only query automatically about a particular host
once per boot.  The variable NETI:*VALIDATE-ONCE-PER-BOOT* can be set to
NIL to cause it to query more often.  If machines frequently go more
than a few days between boots I suggest you do this.

	A few days ago I logged into a freshly booted machine as 
    LISP-MACHINE. I then edited and attempted to save a file. Instead
    of saving the file, the machine writes, "Who are you really?"!

Zmacs knows that LISP-MACHINE is a fake user, so when you save out a
file it asks for a real user name to use when setting the author of the
file.

                                                barmar