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Controlling Subscription Checkpointing in a Publish/Subscribe System

IP.com Disclosure Number: IPCOM000123670D
Original Publication Date: 1999-Mar-01
Included in the Prior Art Database: 2005-Apr-05
Document File: 1 page(s) / 50K

Publishing Venue

IBM

Related People

Bolam, S: AUTHOR [+5]

Abstract

In a message handling system using the Publish/Subscribe concept, such as IBM MQSeries Publish/Subscribe*, the subscriptions which are lodged at each of the brokers in the network may be made persistent by consolidating a large number of subscriptions into a small number of large messages stored on a message queue. The act of consolidating the subscription state is termed checkpointing and this may have a noticeable impact on system performance since generally a broker will need to stop processing new publications while the state is being checkpointed. By using a set of two configuration parameters which MQSeries Publish/Subscribe provides, as described here, the user can control when checkpoints are taken.

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Controlling Subscription Checkpointing in a Publish/Subscribe System

   In a message handling system using the Publish/Subscribe
concept, such as IBM MQSeries Publish/Subscribe*, the subscriptions
which are lodged at each of the brokers in the network may be made
persistent by consolidating a large number of subscriptions into a
small number of large messages stored on a message queue.  The act of
consolidating the subscription state is termed checkpointing and this
may have a noticeable impact on system performance since generally a
broker will need to stop processing new publications while the state
is being checkpointed.  By using a set of two configuration
parameters which MQSeries Publish/Subscribe provides, as described
here, the user can control when checkpoints are taken.

   MQSeries Publish/Subscribe provides the following two
configuration parameters, one which controls checkpointing while a
stream is active, the other which controls checkpointing when a
stream is restarting.

   ChkPtActiveCount
  - The number of changes that need to occur to the subscription
    state before the broker will checkpoint the subscription
    state while a stream is active.

   ChkPtRestartCount
  - The number of changes that need to occur to the subscription
    state before the broker will checkpoint the subscription
    state while a stream is restarting.

   In both cases a value of zero disables checkpointing while
the stream is in that state.  In the abo...