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 get
ting small quantities of time sensitive information effi
ciently from one client (or server) on a network to
another. The object is to accomplish this with the high
est 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
WindowGram 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 failures.
Each client machine on the network runs a zhm(8) HostMan
ager client program which is the link between the Zephyr
servers and the users. User programs send notices to the
HostManager, and the HostManager forwards these notices to
the nearest server for action. The HostManager is respon
sible 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 automatically upon login. Zwgc(1) displays
notices to the user, and handles 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 subscrip
tions 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),
zshutdown_notify(8), syslogd(8)
Project Athena Technical Plan Section E.4.1, `Zephyr Noti
fication Service'
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 Insti
tute of Technology. All Rights Reserved.
Permission to use, copy, modify, and distribute this soft
ware and its documentation for any purpose and without fee
is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
documentation, and that the name of the Massachusetts
Institute of Technology not be used in advertising or pub
licity pertaining to distribution of the software without
specific, written prior permission.
M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFT
WARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS, IN NO EVENT SHALL M.I.T. BE LIABLE FOR ANY
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TOR
TIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE
OR PERFORMANCE OF THIS SOFTWARE.
MIT Project Athena July 1, 1988 ZEPHYR(1)
