NAME¶
zephyr - 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 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) HostManager 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 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 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 subscriptions from Zephyr, to add the
subscriptions to a file, and to perform other miscellaneous functions.
SEE ALSO¶
kerberosintro(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 Notification 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 Institute of Technology. All
Rights Reserved.
Permission to use, copy, modify, and distribute this software 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 publicity pertaining to distribution of the software without
specific, written prior permission.
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 DAMAGES 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.