ZEPHYR(1)ZEPHYR(1)NAMEzephyr - Zephyr Notification Service
DESCRIPTION
Zephyr is a notice transport and delivery system developed at MIT which
runs under 4.3BSD Unix.
A Notice Transport and Delivery system is a method of getting small
quantities of time sensitive information efficiently from one client
(or server) on a network to another. The object is to accomplish this
with the highest possible fan-out (i.e., client to server ratio) while
maintaining both network and server performance. Zephyr is a multi-
cast notice transport and delivery system based upon an authenticated
datagram protocol. Localized Zephyr servers provide routing, queueing
and dispatching services to clients which communicate with them via the
Zephyr Client Library. Two special purpose Zephyr clients, the Window‐
Gram client and the HostManager client provide user and client host
communication support.
Zephyrd(8) servers run on designated server machines. These servers
maintain a database of subscriptions and locations for every user using
Zephyr. The servers stay in contact with one another, and provide a
reliable backup system (via duplication) in the event of network fail‐
ures.
Each client machine on the network runs a zhm(8) HostManager client
program which is the link between the Zephyr servers and the users.
User programs send notices to the HostManager, and the HostManager for‐
wards these notices to the nearest server for action. The HostManager
is responsible for ensuring that the notices reach a server, and for
finding a new one if its server fails to respond.
Each user on the network usually runs a WindowGram client program auto‐
matically upon login. Zwgc(1) displays notices to the user, and han‐
dles user responses. Only notices to which the user has subscribed
will be sent to the WindowGram client.
Subscriptions are handled through the zctl(1) program. This program
allows the user to add or delete subscriptions from Zephyr, to add the
subscriptions to a file, and to perform other miscellaneous functions.
SEE ALSOkerberosintro(1)zaway(1), zctl(1), zleave(1), zlocate(1), znol(1), zwgc(1), zwrite(1),
zmailnotify(1)zhm(8), zephyrd(8), zinit(8), zstat(8), zpopnotify(8), zshut‐
down_notify(8), syslogd(8)
Project Athena Technical Plan Section E.4.1, `Zephyr Notification Ser‐
vice'
AUTHORS
Tony Della Fera (MIT-Project Athena, DEC), Mark W. Eichin (MIT-Project
Athena), Robert S. French (MIT-Project Athena), David C. Jedlinsky
(MIT-Project Athena), John T. Kohl (MIT-Project Athena, DEC), William
E. Sommerfeld (MIT-Project Athena).
RESTRICTIONS
Copyright (c) 1987,1988,1989 by the Massachusetts Institute of Technol‐
ogy. All Rights Reserved.
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, pro‐
vided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in sup‐
porting documentation, and that the name of the Massachusetts Institute
of Technology not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior permis‐
sion.
M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT
SHALL M.I.T. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAM‐
AGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.
MIT Project Athena July 1, 1988 ZEPHYR(1)
