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Browse Prior Art Database

Automatic Host Backup Facility

IP.com Disclosure Number: IPCOM000105549D
Original Publication Date: 1993-Aug-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 4 page(s) / 95K

Publishing Venue

IBM

Related People

Davis, M: AUTHOR [+3]

Abstract

In today's environment, it has become increasingly important for customers to have a system that does not fail, or if it does fail, to become operative again as quickly as possible. This disclosure addresses this customer concern. It provides an automatic backup for sessions attached through a 3174.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Automatic Host Backup Facility

      In today's environment, it has become increasingly important
for customers to have a system that does not fail, or if it does
fail, to become operative again as quickly as possible.  This
disclosure addresses this customer concern.  It provides an automatic
backup for sessions attached through a 3174.

      The primary host connection is provided via the communication
link attached to the 3174, the secondary/backup host connection being
provided via the 3174 CCA attachment using a switched line.  Each
PORT is "CONFIGURED" for two sessions -- one for the primary
connection, call this session LT1; and one for the secondary
connection, call this session LT2.

      The primary connection (LT1) will be active for operators to
perform their work until the primary connection is lost.  The
secondary connection (LT2) will not be active, except when the
primary connection has failed.

      On a primary connection failure, VTAM will note the primary
connection failure and a manual or automatic operation to DIAL OUT
from main processing site to the secondary connection and activate
the secondary link.  VTAM will then send ACTPU on the secondary
connection link, which will activate the 3174 on the secondary
connection.  The 3174 will then, without operator intervention,
"SWITCH" the active LT from LT1 to LT2.  Additionally, all attached
PRINTERS will also be "SWITCHED" from the primary connection to the
secondary connection without operator intervention.

      When the primary connection becomes active again, VTAM will
send ACTPU to the primary connection which will active the primary
connection and deactivate the secondary connection.  The 3174 will
then, without operator intervention, "SWITCH" the active LT from LT2
to LT1.  Additionally, all attached PRINTERS will also be "SWITCHED"
from the secondary connection to the primary connection without
operator intervention.

      This procedure can be extended to handle additional physical
upstream connections beyond the single PRIMARY connection and single
CCA so that additional alternate paths from the applications to the
operator...