Continuous feedback-controlled deployment of message transforms in a distributed messaging system

Abstract

The present invention solves the disadvantages of the prior art and provides a distributed messaging system supporting stateful subscriptions. A stateful publish-subscribe system extends the functionality of the content-based approach to include more general state-valued expressions. A plurality of broker machines is provided to deliver messages sent by publishing clients toward subscribing clients based upon the contents of the messages and stateful transformations requested by the subscribing clients. Subscription specifications are analyzed by a compiler and converted into a collection of message transforms and views. A deployment service component deploys tasks to optimize system performance. A monitoring services component detects a possible need to reconfigure. A performance optimization service component computes new assignment of transforms. A continuous deployment service implements a redeployment protocol that installs changes to transform placement while the existing publish-subscribe system continues to operate.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] The present application is related to U.S. patent application Ser. No. ______, attorney docket no. YOR920040154US1, entitled “DISTRIBUTED MESSAGING SYSTEM SUPPORTING STATEFUL SUBSCRIPTIONS,” filed on an even date herewith, assigned to the same assignee, and incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present invention relates to data processing systems and, in particular, to messaging systems in a distributed processing environment. Still more particularly, the present invention provides a distributed messaging system supporting stateful subscriptions. [0004] 2. Description of Related Art [0005] A publish-subscribe messaging middleware is a system in which there are two types of clients. Publishers generate messages, also referred to as events, containing a topic and some data content. Subscribers request a criterion, also called a subscription, specifying what kind of information, b...

AI Technical Summary

Benefits of technology

[0010] The present invention solves the disadvantages of the prior art and provides a distributed messaging system supporting stateful subscriptions. A stateful publish-subscribe system extends the functionality of the content-based approach to include more general state-valued expressions. Stateful subscriptions may refer to one or more message histories and may include more complex expressions. Therefore, subscribers may receive different information than that provided in the published messages. A plurality of broker machines is provided to deliver messages sent by publishing clients toward subscribing clients based upon the contents of the messages and stateful transformations requested by the subscribing clients. These broker machines form an overlay network. Subscription specifications are either given as a directed transformation graph (with nodes being the transforms required to derive t

Problems solved by technology

Publishers and subscribers are anonymous, meaning that publishers do not necessarily know how many subscribers there are or where they are and, similarly, subscribers do not necessarily know where publishers are.

This is a useful concept; however, in their current manifestations, mediators are comple

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