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WATCHDOG PAGING (FAIL-SAFE FAILURE DETECTION AND SECURITY)

IP.com Disclosure Number: IPCOM000006215D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2001-Dec-14
Document File: 1 page(s) / 57K

Publishing Venue

Motorola

Related People

G. David Mantel: AUTHOR

Abstract

OBJECT Watchdog paging provides a fail-safe method of failure detection and security. OPERATION When the process of interest is operating in the non-failure mode it sends a page at regular time inter- vals. The Watchdog pager receives these pages and does not alert the supervisor. When the process fails it stops sending pages. The Watchdog pager will not receive a page within the specified time period and will time-out. Upon timing-out, the Watchdog pager alerts the supervisor indicating that the process has failed.

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MO7WROLA INC. Technical Developments Volume 13 July 1991

WATCHDOG PAGING (FAIL-SAFE FAILURE DETECTION AND SECURITY)

by G. David Mantel

OBJECT

Watchdog paging provides a fail-safe method of failure detection and security.

OPERATION

  When the process of interest is operating in the non-failure mode it sends a page at regular time inter- vals. The Watchdog pager receives these pages and does not alert the supervisor. When the process fails it stops sending pages. The Watchdog pager will not receive a page within the specified time period and will time-out. Upon timing-out, the Watchdog pager alerts the supervisor indicating that the process has failed.

ADVANTAGES

  Watchdog paging provides two advantages over the alternative method of failure detection. The alter- native method being that of the process sending a page when a failure occurs and the pager alerting the super- visor upon receiving a page.

  The first advantage of Watchdog paging is that in some instances if a process fails it may not be capable of sending a page (i.e. a catastrophic failure). In this

case the alternative method would not alert the super- visor of a process failure while Watchdog paging would.

  The second advantage is observed by analyzing what happens if the communication link between the process and the supervisor (telephone system, paging terminal, transmitter) fails. If the process were to fail under such a condition the alternative method would fail to alert the supervisor of the fail...