Abstract:
A dynamic topic partitioning messaging system. The messaging system can include a message server; one or more topics stored in the message server; one or more subtopics associated with at least one of the topics in the message server; and, a dynamic topic partitioning system configured to partition the topics into the subtopics. Notably, the message server can be Java message service (JMS) compliant. In that regard, the message server can reside in a single process address space. For example, the process address space can be a Java virtual machine (JVM).

Description:
BACKGROUND OF THE INVENTION 
     1. Statement of the Technical Field 
     The present invention relates to asynchronous communications and more particularly to messaging systems. 
     2. Description of the Related Art 
     Distributed applications have begun to proliferate, as have a host of previously unexplored problems associated with message synchronization, transmission reliability, system scalability, and message security. Present solutions include conventional messaging systems formed from loosely coupled components communicating with one another with asynchronous messages. Notably, conventional messaging systems have been used to build highly reliable, scalable, and flexible distributed applications. 
     At its core, the conventional messaging system permits separate, uncoupled applications to reliably communicate in an asynchronous manner. Importantly, the messaging system architecture generally replaces the client/server model with a peer-to-peer relationship between individual computing components, wherein each peer computing component can send and receive messages to and from other peer computing components. In consequence, messaging systems can provide several significant advantages over other, more conventional distributed computing models. 
     For instance, messaging systems encourage “loose coupling” between message consumers and message producers. Specifically, there exists a high degree of anonymity between producer and consumer. In fact, from the perspective of the message consumer, it does not matter who produced the message, where the producer resided in the computing network, and when the message had been produced. As a result, dynamic, reliable, and flexible systems can be assembled whereby entire ensembles of sub-applications can be modified without affecting the remaining portion of the system. In any event, conventional messaging systems assume one of two messaging systems models: publish/subscribe and point-to-point. 
     The publish/subscribe messaging system supports an event driven model where consumers and producers participate in the transmission of messages. Producers “publish” messages, while consumers “subscribe” to messages of interest, and consume the messages. More particularly, producers associate messages with a specific topic, and the messaging system routes messages to consumers based upon the topics for which consumers have registered. In point to point messaging systems, by comparison, messages are routed to an individual consumer which maintains a queue of “incoming” messages. Messaging applications send messages to a specified queue, and clients retrieve messages from a queue. 
     The Java™ Message Service (JMS), part of the Java 2 Enterprise Edition (J2EE™) suite manufactured by Sun Microsystems of Palo Alto, Calif., provides standard APIs that Java developers can use to access the common features of enterprise messaging systems. JMS supports both the publish/subscribe and point-to-point models and allows the creation of message types consisting of arbitrary Java objects. A fundamental design goal of JMS is to provide a consistent set of interfaces that messaging system clients can use independent of the underlying message system provider. In this way, not only are client applications portable across machine architectures and operating systems, but the client applications also remain portable across messaging products. 
     Still, in JMS only a single thread can be used to service a messaging system subscriber receiving any published message for a customer defined topic in which it is interested. In consequence, if enough message traffic is generated for that topic, a single thread in a multithreaded virtual machine can become overrun fairly quickly. Accordingly, what is needed is a messaging system in which multiple threads can service a messaging system subscriber receiving any published message for a customer defined topic. 
     SUMMARY OF THE INVENTION 
     The present invention is a messaging system which overcomes the single threaded deficiencies of the prior art and provides a novel and non-obvious system and method for dynamically partitioning a message topic into one or more subtopics so that multiple threads can service publishers and subscribers of messages associated with the message topic. A messaging system which has been configured in accordance with one aspect of the present invention can include a message server; one or more topics stored in the message server; one or more subtopics associated with at least one of the topics in the message server; and, a dynamic topic partitioning system configured to partition the topics into the subtopics. 
     Notably, the message server can be Java message service (JMS) compliant. In that regard, the message server can reside in a single process address space. For example, the process address space can be a Java virtual machine (JVM). In consequence, the message system can include a multiplicity of threads of execution, each thread hosting a process for communicating a message between one of the subtopics in the message server and a message subscriber. 
     A dynamic topic partitioning system which can be used in the messaging system of the present invention can include a message interface through which message publishers can post messages to selected topics, and from which message subscribers can request messages which have been published to selected topics. A subtopic store can be included. The subtopic store can be configured to distribute messages of the selected topics within associated subtopics. Finally, the system can include a request processor in which requests to post and retrieve messages to and from individual ones of the selected topics can be converted into message system requests to respectively post and retrieve messages to and from the associated subtopics in the subtopic store. Notably, the request processor can process each of the converted message system requests in individual threads of execution. 
     A message system servicing method for use with a message server in a message system can include intercepting message requests for a selected topic from subscribers in the message system. The message requests can be associated with subtopics created for the selected topic. In consequence, the message requests can be services with messages in the subtopics from within separate threads of execution for each subtopic-subscriber pair. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       There are shown in the drawings embodiments which are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein: 
         FIG. 1  is an schematic illustration of a messaging system which has been configured according to the inventive arrangements; 
         FIG. 2  is a block illustration of a dynamic messaging partitioning process for use in the messaging system of  FIG. 1 ; 
         FIG. 3A  is a flow chart illustrating a process for partitioning a message topic into subtopics during topic creation; and, 
         FIG. 3B  is a flow chart illustrating a process for distributing messages which have been partitioned into the subtopics of  FIG. 3A  during message subscription. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is a messaging system which allows for the creation of multiple publisher and subscriber threads for a selected topic in a publish/subscribe messaging system. In particular, in accordance with the inventive arrangements, selected message topics in a message server can be subdivided into individual subtopics on a per subscriber or per publisher basis. Subsequently, requests to subscribe to messages from the selected message topic can be intercepted and associated with a suitable one of the subtopics in a separate thread. In this way, subscriber threads can be established on a subtopic basis rather than a complete topic basis. Hence, message traffic overruns can be avoided an enhanced scalability provided for in the messaging system. 
       FIG. 1  is a schematic illustration of a messaging system which has been configured according to the inventive arrangements. The messaging system can include one or more publishers  102  and one or more subscribers  104 . Each publisher  102  can post messages to a selected topic in a message server  115  in the messaging system. Conversely, each subscriber  104  can receive messages from the message server  115  based upon those message topics for which the subscribers  104  have subscribed. Notably, unlike a conventional messaging system, in the messaging system of the present invention, a dynamic topic partitioning system  120  can be provided. 
     The dynamic topic partitioning system  120  can transparently intercept requests from publishers  102  to post messages to a selected topic in fixed storage  110  in the message server  115 . Specifically, as only a single thread can be allocated per subscriber per topic in a conventional messaging system, in the present invention, the dynamic topic partitioning system  120  can partition the selected topic into one or more subtopics in fixed storage  110 . Additionally, the dynamic topic partitioning system  120  can distributed messages for the selected topic to individual ones of the subtopics. In consequence, when a subscriber  104  retrieves messages from the selected topic, multiple threads can be used to retrieve the messages. 
       FIG. 2  is a block illustration of a dynamic messaging partitioning process for use in the messaging system of  FIG. 1 . Typically, topics are created during the initialization of the messaging system. Hence, during initialization each attempt to create a topic  210  can be intercepted by the dynamic topic partitioning system  120 . Specifically, upon intercepting a request to create a topic  210 , the dynamic topic partitioning system  120  can create one or more subtopics  220  and can assign selected subscribers  104  to the subtopics  220 . Notwithstanding, the invention is not limited in this regard and the topics  210  can be subdivided into subtopics  220  dynamically subsequent to initialization. 
     In any case, when a publisher  102  posts a message  202  to the topic  210 , the message  202  can be posted in a selected one of the subtopics  220  programmatically. That is, each message  202  posted to the topic  210  can be intercepted by the dynamic topic partitioning system  120  and assigned to a particular subtopic  220 , based on a distribution algorithm, such as randomly selecting one of the subtopics  220  to which the message  202  can be posted. Still, the invention is not limited in regard to the method by which messages  202  are distributed to particular subtopics  220 . 
     Importantly, individual ones of the subscribers  104  can retrieve messages  202  posted to the selected topic  210  in the messaging system. Each attempt to retrieve a message  202 , however, can be intercepted by the dynamic topic partitioning system  120 . More particularly, upon intercepting a message  202 , the dynamic topic partitioning system  120  can determine whether a subtopic  220  has been created for the particular subscriber  104  to the selected topic  210 . If a subtopic  220  has been created, the message  202  can be retrieved therefrom within its own thread. Otherwise, the message can be retrieved directly from the selected topic  210  using a single thread. By partitioning the selected topic  210  into multiple subtopics  220 , however, multiple individual threads can be allocated for each subscriber  104  retrieving messages  202  from the selected topic  210 . 
       FIG. 3A  is a flow chart illustrating a process for partitioning a message topic into subtopics during topic creation. Beginning in step  302 , a request to create a topic can be intercepted. In step  304 , the topic can be subdivided into multiple subtopics. The number of subtopics created can vary, for example, according to either a pre-specified number, or a number proportional to an anticipated number messages posted to the topic during a given time interval. In any case, in step  306 , subscribers can be assigned to the topic. Finally, in step  308 , subsequently posted messages to the topic can be distributed among the subtopics according to a distribution formula, for instance in wrap-around sequential order. 
       FIG. 3B  is a flow chart illustrating a process for distributing messages which have been partitioned into the subtopics of  FIG. 3A  during message subscription. Beginning in step  312 , a request for messages from a topic can be received from a subscriber. In block  314 , subtopics for the topic can be located and in block  316 , individual retrieval threads can be established with the subscriber for each subtopic. In block  318 , the messages in each subtopic can be forwarded to the subscriber. Thus, multiple threads can be used to distribute messages to a subscriber from within a single topic. 
     The present invention can be realized in hardware, software, or a combination of hardware and software. An implementation of the method and system of the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein. 
     A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computer system is able to carry out these methods. 
     Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.