


ZEPHYR(1)                 User Commands                 ZEPHYR(1)



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  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 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 authenti-
     cated  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 communi-
     cation support.

     _Z_e_p_h_y_r_d(_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 _z_h_m(_8) HostManager
     client  program which is the link between the Zephyr servers
     and the users.  User programs  send  notices  to  the  Host-
     Manager,  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 find-
     ing a new one if its server fails to respond.

     Each user on the network usually runs  a  WindowGram  client
     program  automatically upon login.  _Z_w_g_c(_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 _z_c_t_l(_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)



MIT Project Athena  Last change: July 1, 1988                   1






ZEPHYR(1)                 User Commands                 ZEPHYR(1)



     Project Athena Technical Plan Section E.4.1, `Zephyr Notifi-
     cation 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 docu-
     mentation,  and that the name of the Massachusetts Institute
     of Technology not be used in advertising or  publicity  per-
     taining  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 MERCHANTABIL-
     ITY 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  Last change: July 1, 1988                   2



