ken@cs.cornell.edu (Ken Birman) (04/21/91)
We are tentatively planning to eliminate the namespace "scope"
feature from ISIS. Feedback appreciated...
The feature in question:
In V2.1, your sites configuration file is supposed to divide the
sites into sets called "search scopes". Each site has a default
scope (first one on the line) and may list additional scope names
as well.
Searches for groups were done within the default scope only,
unless the group name was specified as "@scope:name", in which
case the specified scope was searched.
Rationale for eliminating this:
1) The feature was rarely if ever used and caused a number of
problems. A typical error would be a minor sites file formatting
problem that prevents applications from "seeing" each other.
2) The move to a pathname style group name space seems to eliminate
the need to partition the namespace, in any case
3) The big improvement in performance with isis_remote_init under V3.0
(and later, V2.2) will result in configurations with small "backbone"
networks, hence there is only a weak performance justification for
the scope feature.
What to expect:
In V3.0 (general release) and V2.2, calls using group names with
an explicit scope reference will be (noisily) rejected.
New system call isis_getscope(char *sname, bitvec *bv) will let
applications obtain the scope data from the sites file, in case
they have some use for it. For example
isis_getscope("sparc", bv)`
will leave bit i set in bv if site "i" has "sparc" listed on its
sites-file definition line. (Use bit(bv, i) to test for this)
Please feel free to comment on this
-- Ken
--
Kenneth P. Birman E-mail: ken@cs.cornell.edu
4105 Upson Hall, Dept. of Computer Science TEL: 607 255-9199 (office)
Cornell University Ithaca, NY 14853 (USA) FAX: 607 255-4428