Re: New Symbolics world load for 3600s (bug)

[Web Dove <dove@bugs-bunny>]

It seems that the world load has lm15 listed as a secondary to MIT
which is incorrect.  It is best to correct that fact before resaving the
world.

This is a problem I have noticed with the scrc namespace.  The problem
can be observed by using the function (query-namespace ...) defined in
tweety:>util>query-namespace.(lisp/bin).  This uses the function
(neti:query-namespace-server class namespace properties) to find out
current information about objects.  It prints whether the information
was found on the server, whether the server considered it valid, and
whether the information was found locally using find-object-named.

It has usually been the case that when the primary was down, queries
about objects in some namespace went out to secondaries of that
namespace and came back "present but invalid" since the secondary
couldn't verify the requested information.  However, on some occasions
the server claimed that the information was present and valid even
though it was out of date.

This is what happened to me with the scrc namespace as seen from the scrc
namespace with a query from daffy to ap6.  Apparently, ap6 was out of
contact with scrc.  From daffy I asked for namespace scrc in namespace
scrc via the following request:
(query-namespace :namespace "scrc" :scrc)
This came back valid and present, but showed lm15 as a secondary.

I telneted to ap6 and tried the same query.  From there it came back
invalid and present.  So ap6 knew the info was out of date and claimed
that it was valid anyway!!  I then reset-host-availabilities on ap6,
redid the query and got valid information.  Then tried the same back on
daffy and got valid information.  The important fact was that daffy had
know way of being sure that ap6 hadn't lied!  Only if you were using ap6
itself could you tell that the info was invalid.

To make a long story short I have the following suggestion for
maintainers of secondaries.  In the file query-namespace.bin is another
function (validate-namespace) that resets all host availabilities and
then tries lots of queries for important things like namespaces and
networks and primaries and secondaries (and some unimportant things like
:user dove).  Please load this function and see that it evaluates
completely before saving worlds on secondaries!  This will save the rest
of us undue grief.