1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
|
.\" $Id$
.\"
.\" Copyright 1987,1988 by the Massachusetts Institute of Technology
.\" All rights reserved. The file /usr/include/zephyr/mit-copyright.h
.\" specifies the terms and conditions for redistribution.
.\"
.TH ZEPHYR 1 "July 1, 1988" "MIT Project Athena"
.ds ]W MIT Project Athena
.SH NAME
zephyr \- Zephyr Notification Service
.SH DESCRIPTION
.PP
Zephyr is a notice transport and delivery system developed at MIT
which runs under 4.3BSD Unix.
.PP
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.
.PP
.I 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.
.PP
Each client machine on the network runs a
.I 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.
.PP
Each user on the network usually runs a WindowGram client program
automatically upon login.
.I 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.
.PP
Subscriptions are handled through the
.I 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.
.SH SEE ALSO
kerberosintro(1)
.br
zaway(1), zctl(1), zleave(1), zlocate(1), znol(1), zwgc(1),
zwrite(1), zmailnotify(1)
.br
zhm(8), zephyrd(8), zinit(8), zstat(8), zpopnotify(8),
zshutdown_notify(8), syslogd(8)
.br
Project Athena Technical Plan Section E.4.1, `Zephyr Notification
Service'
.SH AUTHORS
.PP
.br
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).
.SH RESTRICTIONS
Copyright (c) 1987,1988,1989 by the Massachusetts Institute of Technology.
All Rights Reserved.
.br
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.
.br
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.
|