Event-Based Activation and Deactivation of Subscription Matching

• US 20080134202A1
• Filed: 11/30/2007
• Published: 06/05/2008
• Est. Priority Date: 11/30/2006
• Status: Active Grant

• Current Assignee: Beijing Zitiao Network Technology Company Limited (ByteDance Ltd.)
• Original Assignee: International Business Machines Corporation
• Inventors: Locke, David, Garrard, Anthony Alan, Hickson, Andrew Ian, Harwood, Ian Robert, Stockdill, Jane Louise, Craggs, Ian Gerald, Stanford-Clark, Andrew James, Reynolds, Andrew David
• Granted Patent: US 8,082,554 B2
• Time in Patent Office: Days
• US Class Current: 719/313
• CPC Class Codes: G06F 2209/544 Remote
• CPC Class Codes: G06F 2209/547 Messaging middleware
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

The present invention provides methods, apparatus and computer programs for event-based control of subscription matching in a publish/subscribe communications environment. Activation and/or deactivation events are associated with subscriptions at a publish/subscribe broker and are used to control when a subscription is active. The broker is responsive to temporally-unpredictable events, such as receipt of a published message on a predefined activation topic, to activate subscription matching for messages that are subsequently received or which have been received earlier and retained at the broker. Conventional subscription matching can be avoided for a registered subscription while that subscription is inactive, and subscribers are not required to explicitly and repeatedly subscribe and unsubscribe.

Claims

1. A method of managing subscription matching within a publish/subscribe communications network, comprising:

storing a subscription at a publish/subscribe broker for a first subscriber, wherein the subscription comprises at least one temporally unpredictable event for controlling the performance of subscription matching;

monitoring events at the publish/subscribe broker to detect said event, and

altering the state of subscription matching performed on behalf of the first subscriber in response to detection of said event.

2. A method according to claim 1 wherein the subscription defines a first topic to compare with received messages during subscription matching, and wherein the defined event is the event of receiving a message at the publish/subscribe broker, which message includes a predefined topic that differs from the first topic.

3. A method according to claim 2, further comprising checking whether the received message satisfies a set of one or more filter conditions associated with the predefined topic, wherein the state of subscription matching is altered in responsive to a positive determination that the received message satisfies the set of filter conditions.

4. A method according to claim 3, further comprising storing subscriptions on behalf of multiple subscribers, which subscriptions define a common event, and the state of subscription matching on behalf is altered on behalf of said multiple subscribers in response to the common event.

5. A method according to claim 4 wherein said event is an activation event and subscription matching is activated in response to detection of the activation event.

6. A method according to claim 5 wherein said event is a deactivation event and subscription matching is deactivated in response to detection of said deactivation event.

7. A data processing apparatus for managing subscription matching within a publish/subscribe communications network, comprising:

a repository for storing a subscription on behalf of at least one subscriber, wherein the subscription comprises at least one temporally unpredictable event for controlling the performance of subscription matching;

a publish/subscribe broker comprising a matching engine for subscription matching; and

an event monitor for detecting an occurrence of said event at the publish/subscribe broker;

said publish/subscribe broker being responsive to detection of said event to alter the state of subscription matching performed on behalf of the at least one subscriber.

8. A data processing apparatus according to claim 7 wherein the subscription defines a first topic to compare with received messages during subscription matching, and wherein the defined event is the event of receiving a message at the publish/subscribe broker, which message includes a predefined topic that differs from the first topic.

9. A data processing apparatus according to claim 8, further comprising filtering logic for checking whether the received message satisfies a set of one or more filter conditions associated with the predefined topic, wherein the state of subscription matching is altered in responsive to a positive determination that the received message satisfies the set of filter conditions.

10. A data processing apparatus according to claim 9, further comprising control logic for storing subscriptions on behalf of multiple subscribers, which subscriptions define a common event, and wherein the state of subscription matching on behalf is altered on behalf of said multiple subscribers in response to occurrence of the common event.

11. A computer program product for managing subscription matching within a publish/subscribe communications network, said computer program product comprising a computer usable medium having computer usable program code embodied therewith, said computer usable program code comprising:

computer usable program code configured to store a subscription at a publish/subscribe broker for a first subscriber, wherein the subscription comprises at least one temporally unpredictable event for controlling the performance of subscription matching;

computer usable program code configured to monitor events at the publish/subscribe broker to detect an occurrence of said event; and

computer usable program code configured to alter the state of subscription matching performed on behalf of the first subscriber in response to detection of said event.

12. A computer program product program according to claim 11 wherein the subscription defines a first topic to compare with received messages during subscription matching, and wherein the defined event is the event of receiving a message at the publish/subscribe broker, which message includes a predefined topic that differs from the first topic.

13. A computer program product according to claim 12 further comprising computer usable program code configured to check whether the received message satisfies a set of one or more filter conditions associated with the predefined topic, wherein the state of subscription matching is altered in responsive to a positive determination that the received message satisfies the set of filter conditions.

14. A computer program product according to claim 13 further comprising:

computer usable program code configured to store subscriptions on behalf of multiple subscribers, which subscriptions define a common event; and

computer usable program code configured to alter the state of subscription matching performed on behalf of said multiple subscribers in response to detection of the common event.

15. A computer program product according to claim 14 wherein said event is an activation event and subscription matching is activated in response to occurrence of said activation event.

16. A computer program product according to claim 15 wherein said event is a deactivation event and subscription matching is deactivated in response to occurrence of said deactivation event.