# Patent

## Title
Peer-to-peer collaboration of publishers in a publish-subscription environment

## Abstract

Embodiments of the present invention provide an approach for an enhanced pub/sub environment whereby a peer group of publishers is defined and can collaborate to determine when to cache data being sent to a common broker or brokers. Specifically, in a typical embodiment, configuration data or the like will be read to define a peer group among the publisher systems in the pub/sub messaging environment. Once such a group has been identified, communication therebetween will be established. Once cacheable data has been identified, a unique identifier/set of cache keys will be generated corresponding thereto and associated with the set of data. A message comprising the set of data and corresponding unique identifier will then be sent to a broker system (e.g., from the publisher system(s)), which will store (or have stored) the set of data in a cache, and pass the underlying message along to applicable subscriber system(s).

## Background
RELATED U.S. APPLICATION DATA
The present patent document is a continuation of U.S. patent application Ser. No. 13/033,639, filed Feb. 24, 2011, entitled “PEER-TO-PEER COLLABORATION OF PUBLISHERS IN A PUBLISH-SUBSCRIPTION ENVIRONMENT”. The disclosure of U.S. patent application Ser. No. 13/033,639 is incorporated herein by reference.


TECHNICAL FIELD
The present invention relates to publish-subscription (pub/sub) environments. Specifically, the present invention relates to an approach for caching potentially repetitive data in a pub/sub environment via peer-to-peer (P2P) collaboration of publishers.
BACKGROUND
Publish-subscription (pub/sub) messaging patterns are communication models used in many different industries today. For example, pub/sub is used in banking systems, weather systems, and other systems that require techniques to notify multiple entities of common information. In general, pub/sub is a messaging paradigm where senders (publishers) of messages typically are not programmed to send their messages to specific receivers (subscribers). Rather, published messages can be characterized into classes, without knowledge of what (if any) subscribers there may be. Subscribers express interest in one or more classes and can receive messages that are of interest, without knowledge of what publishers there are. This decoupling of publishers and subscribers can allow for greater scalability and a more dynamic network topology.
One deficiency in pub/sub models is that all of the content (i.e., the body/payload of the message) is sent to all users, and thus the amount of network traffic generated from the publisher is, in the simplest form, the size of the message multiplied by the number of subscribers. Moreover, it can be common for the same set of data to be re-sent multiple times (in different messages) to the same subscriber(s). As such, the volume of the data generated can be large and consume a great deal of network bandwidth.
SUMMARY
In general, embodiments of the present invention provide an approach for an enhanced pub/sub environment whereby a peer group of publishers is defined and can collaborate to determine when to cache data being sent to a common broker or brokers (e.g., identify data that is common to multiple publishers which may be cachable). Specifically, in a typical embodiment, configuration data or the like will be read to define a peer group among the publisher systems in the pub/sub messaging environment. Once such a group has been identified, communication among the peers therein will be established. This communication will be utilized to identify a set of data that is common to the set (at least one) of publisher systems in the peer group, which has a potential to be cacheable. Once such data has been identified, a unique identifier/set of cache keys will be generated corresponding thereto, and associated with the set of data. A message comprising the set of data and corresponding unique identifier will then be sent to a broker system (e.g., from the publisher system(s)), which will store (or have stored) the set of data in a cache, and pass the underlying message along to applicable subscriber system(s). When a future message is to be generated with the set of data previously cached, the publisher system will instead substitute the unique identifier for the cached set of data to yield an abbreviated message, which is sent to the broker system. Upon receipt of the abbreviated message, the broker system will locate the unique identifier, retrieve the corresponding set of data from cache, substitute the set of data for the unique identifier to yield a completed message, and send the completed message to the applicable subscriber system(s).
A first aspect of the present invention provides a method for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, comprising: establishing P2P communication between a set of publisher systems in the pub/sub messaging environment; identifying a set of data that is common to the set of publisher systems having a potential to be cached; generating a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable; sharing the unique identifier among the set of publisher systems; associating the set of data with the unique identifier; and sending a first message having the set of data and the unique identifier to a broker system in the pub/sub messaging environment.
A second aspect of the present invention provides a system for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, comprising: at least one bus; at least one processor coupled to the at least one bus; and at least one memory medium coupled to the at least one bus, the at least one memory medium comprising instructions to: establish P2P communication between a set of publisher systems in the pub/sub messaging environment; identify a set of data that is common to the set of publisher systems having a potential to be cached; generate a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable; share the unique identifier among the set of publisher systems; associate the set of data with the unique identifier; and send a first message having the set of data and the unique identifier to a broker system in the messaging pub/sub environment.
A third aspect of the present invention provides an at least one computer program product for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, the at least one computer program product comprising at least one computer readable storage media, and program instructions stored on the at least one computer readable storage media, to: establish P2P communication between a set of publisher systems in the pub/sub messaging environment; identify a set of data that is common to the set of publisher systems having a potential to be cached; generate a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable; share the unique identifier among the set of publisher systems; associate the set of data with the unique identifier; and send a first message having the set of data and the unique identifier to a broker system in the pub/sub messaging environment.
A fourth aspect of the present invention provides a method for deploying a system for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, comprising: providing a computer infrastructure being operable to: establish P2P communication between a set of publisher systems in the pub/sub messaging environment; identify a set of data that is common to the set of publisher systems having a potential to be cached; generate a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable; share the unique identifier among the set of publisher systems; associate the set of data with the unique identifier; and send a first message having the set of data and the unique identifier to a broker system in the pub/sub messaging environment.



BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which:
FIG. 1 depicts a computing node according to an embodiment of the present invention.
FIG. 2 depicts a pub/sub environment according to an embodiment of the present invention.
FIG. 3 depicts a component flow diagram according to an embodiment of the present invention.
FIG. 4 depicts another component flow diagram according to an embodiment of the present invention.
FIG. 5 depicts a method flow diagram according to an embodiment of the present invention.
FIG. 6 depicts another method flow diagram according to an embodiment of the present invention.



The drawings are not necessarily to scale. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting the scope of the invention. In the drawings, like numbering represents like elements.
DETAILED DESCRIPTION
Illustrative embodiments will now be described more fully herein with reference to the accompanying drawings, in which exemplary embodiments are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those skilled in the art. In the description, details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the presented embodiments.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the use of the terms “a”, “an”, etc., do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including”, when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.
In general, embodiments of the present invention provide an approach for an enhanced pub/sub environment whereby a peer group of publishers is defined and can collaborate to determine when to cache data being sent to a common broker or brokers (e.g., identify data that is common to multiple publishers which may be cachable). Specifically, in a typical embodiment, configuration data or the like will be read to define a peer group among the publisher systems in the pub/sub messaging environment. Once such a group has been identified, communication among the peers therein will be established. This communication will be utilized to identify a set of data that is common to the set (at least one) of publisher systems in the peer group, which has a potential to be cacheable. Once such data has been identified, a unique identifier/set of cache keys will be generated corresponding thereto, and associated with the set of data. A message comprising the set of data and corresponding unique identifier will then be sent to a broker system (e.g., from the publisher system(s)), which will store (or have stored) the set of data in a cache, and pass the underlying message along to applicable subscriber system(s). When a future message is to be generated with the set of data previously cached, the publisher system will instead substitute the unique identifier for the cached set of data to yield an abbreviated message, which is sent to the broker system. Upon receipt of the abbreviated message, the broker system will locate the unique identifier, retrieve the corresponding set of data from cache, substitute the set of data for the unique identifier to yield a completed message, and send the completed message to the applicable subscriber system(s).
The approaches described herein provide a solution to optimize network traffic between publishers and brokers and provide a system that works in complex production environments commonly found where only uni-directional communication is available between publishers and brokers. Similarly, in low latency networks, it may not be ideal to have two-way communications between the publisher and broker.
It is noted that caching of data hereunder could occur via the publisher system, the broker system and/or the subscriber system. Along these lines, the location of the cache is not intended to be limiting.
Referring now to FIG. 1, a schematic of an example of a computing node is shown. Computing node 10 is only one example of a suitable computing node and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, computing node 10 is capable of being implemented and/or performing any of the functionality set forth hereinabove.
In computing node 10, there is a computer system/server 12, which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 12 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed computing environments that include any of the above systems or devices, and the like.
Computer system/server 12 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 12 may be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.
As shown in FIG. 1, computer system/server 12 in computing node 10 is shown in the form of a general-purpose computing device. The components of computer system/server 12 may include, but are not limited to, one or more processors or processing units 16, a system memory 28, and a bus 18 that couples various system components including system memory 28 to processor 16.
Bus 18 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus.
Computer system/server 12 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 12, and it includes both volatile and non-volatile media, removable and non-removable media.
System memory 28 can include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and/or cache memory 32. Computer system/server 12 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 34 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM, or other optical media can be provided. In such instances, each can be connected to bus 18 by one or more data media interfaces. As will be further depicted and described below, memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of embodiments of the invention.
The embodiments of the invention may be implemented as a computer readable signal medium, which may include a propagated data signal with computer readable program code embodied therein (e.g., in baseband or as part of a carrier wave). Such a propagated signal may take any of a variety of forms including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium including, but not limited to, wireless, wireline, optical fiber cable, radio-frequency (RF), etc., or any suitable combination of the foregoing.
Program/utility 40, having a set (at least one) of program modules 42, may be stored in memory 28 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. In general, program/utility 40 performs the function of the present invention as described herein. Each of the operating systems, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 42 generally carry out the functions and/or methodologies of embodiments of the invention as described herein. Computer system/server 12 may also communicate with one or more external devices 14 such as a keyboard, a pointing device, a display 24, etc.; one or more devices that enable a consumer to interact with computer system/server 12; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 12 to communicate with one or more other computing devices. Such communication can occur via I/O interfaces 22.
Still yet, computer system/server 12 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 20. As depicted, network adapter 20 communicates with the other components of computer system/server 12 via bus 18. It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server 12. Examples include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
Embodiments of the present invention provide an approach for a publisher-based cache that can be utilized to reduce the volume of data (network traffic) delivered to individual subscribers in a pub/sub system.
Referring now to FIG. 2, a pub/sub environment 70 in accordance with at least one embodiment of the present invention is shown in greater detail. As depicted, environment 70 comprises a publisher system 72 (also referred to below as “publisher”) in communication with a subscriber system 74 (also referred to below as “subscriber”) via a broker system 76 (also referred to below as “broker”). Systems 72, 74, and 76 communicate via network links 78A-N, which can represent any type of network links and/or communication networks now known or later developed. It is understood that publisher system 72, subscriber system 74, and broker system 76 each comprise one or more computer systems 12A-C (e.g., which comprises components/elements similar to computer system 12 of FIG. 1). As such, publisher system 72, subscriber system 74, and broker system 76 can each comprise a program/utility 40A-C that enable corresponding functions thereof. Specifically, publisher system 72 comprises publisher program 40A having a set (at least one) of publisher program modules 42A, broker system 76 comprises broker program 40B having a set of broker program modules 42B, and subscriber system 74 comprises a subscriber program 40C having a set of subscriber program modules 42C. Program modules 42A-C of programs 40A-C typically enable/perform the functions that will be described below in conjunction with FIGS. 3-5.
Referring now to FIG. 3, a component flow diagram illustrating the process involved with a typical embodiment of the present invention is shown in greater detail. It is understood in advance that where identical steps are shown as being performed by multiple publishers, only a single instance may need to be performed. Identical steps are shown in parallel to illustrate that the cache engines 110A-B of either publisher system could carry out the underlying functionality. In steps S1A-B, publisher systems first learn what peers are in their peer group. This may be done via a configuration file that is read or some other means by which the publisher learns about its peers. In one embodiment, an administrator or the like could provide this information when the publisher is created. The publisher systems in a peer group will establish communication between its peer(s) in steps S2A-B. This may be a simple one to one relationship, one-to-many, or many-to-many. The peer group may define a master peer or some other hierarchy for managing communications between the peer group. As a publisher system runs, either by itself or in conjunction with the peer group, the publisher system will determine what data is publishing, which should be cached in steps S3A-B.
Along these lines, the identification process can be configured with attributes such as one or more of the following:

    
    
        If data is going to be in more than “N” number of messages;
        If data is going to be in more than “M” number of messages and is over X′′ number of bytes.
        These determinations can be made based upon historical information of messages already published or about the types of data typically published (e.g., common extensible markup language (XML) schemas that are known to be published may have common, lengthy tags or sequences of tags that can be cached).
    
    


The collaboration between the peer group is then used to further determine what data should be cached. For instance, if the rule for an individual publisher states that data should be cached if the data has occurred in ten or more past messages, the peer group may define a rule that states if the data has occurred at least twice, historically check with the peer group and see if, as a group, the data is seen ten or more times (or some other configurable value). If those criteria have been met, then have the peer group cache this data. Likewise, the default rule may be that if an individual publisher system determines that specific data should be cached that all publishers in the peer group should be notified and always use the cache keys/unique identifiers associated with the data. Along these lines, the cache keys/unique identifier is established for the data in step S4A or S4B. In this step, it is not necessary for more than one publisher system to generate the unique identifier. As such, only step S4A or S4B need to be performed. Along these lines, the generation of cache keys/unique identifiers could be done by a master peer in the group, negotiated between peers, or some other method. Regardless, once the cache key/unique identifier is created and associated with the data, it is shared among all peers in the peer group in steps S5A-B.
In steps S6A-B the message is processed. This typically involves tagging/annotating/associating the cacheable data in the message with the cache keys/unique identifier, and need only be performed by a single publisher system. This process could be implemented using one of the methods described in the sections below entitled: Potential Implementations I and II. Once the message has been processed, it is published in step S7A or S7B, and received by the broker system in step S8. Upon receipt, the broker system will process the message in step S9, and send the message to applicable subscriber system(s) in step S10, which will be received in step S11.
The processing of messages in step S9 by the broker system cache engine 100 will be described in greater detail with respect to FIG. 4. However, in general, the broker system cache engine 100 will detect and locate the unique identifier within the message, and store (or have stored) the corresponding data in a cache (e.g., a broker system cache, a subscriber system cache, etc.). Then, when a message is later received having the unique identifier (e.g., an abbreviated message is received), the broker system cache engine 100 will retrieve the corresponding data, replace the unique identifier in the message with the retrieved data to yield a completed message, and then send the completed message to the applicable subscriber system(s).
Although not shown, the subscriber can have access to the broker system cache and/or maintain its own cache. This allows the subscriber to maintain or have access to previously cached data. Regardless, when the publisher is creating a message with previously cached data, the publisher system will substitute the unique identifier for such data to yield an abbreviated message, and then send the abbreviated message to the broker system. Upon receipt, the broker system can then locate the unique identifier in the abbreviated message, retrieve the associated data from the cache, replace the unique identifier in the message with the retrieved data, and then send the completed message to the applicable subscriber system(s). Alternatively, in the event the subscriber system(s) maintain or have access to the cached data, the abbreviated message received by the broker system from the publisher system can be sent to the subscriber system(s), which can retrieve the previously cached data that can be used by the subscriber system(s) to complete the message (e.g., via a subscriber cache engine).
Referring now to FIG. 4, the functions of broker cache engine 100 will be described in greater detail. In step R1, a message/publication is received from the publisher system. In step R2, it is determined whether new items need to be cached. If so, they are stored in data store/cache 140 in step R3. Once all cacheable data items have been so stored, the message is analyzed to see if it includes unique identifier(s) corresponding to data cached from previous messages (e.g., the message is an abbreviated message) in step R4. If so, that data is retrieved from cache 140 and inserted into the message. Once all new cacheable data has been cached, and previously cached data has been retrieved, it is determined in step R5 whether or not the message included cache keys/unique identifiers (pertaining to previously cached data) that were not valid (e.g., the cache keys/unique identifiers did not appear to be associated with any data stored in cache 140). If so, the cache can be invalidated in step R7, and a refresh of cache 140 can be requested from the publisher system in step R8. Regardless, once any broker-side processing is complete, the message can be sent to the subscriber system(s) in step R6. As indicated above, the subscriber system(s) can receive either a completed message (e.g., based on step R4) or an abbreviated message in the event the subscriber system(s) have access to previously cached data as indicated above.
It is understood that it may be beneficial to allow a broker system to invalidate cache items on a publisher system and/or a subscriber system. If, for example, the broker's cache engine can determine that data previously cached is never used again, or has a very low likelihood of being used again, it may send an invalidation message upon the next publish to the other system(s). This may be implemented as a custom header that contains the key and an invalidate directive. The subscriber system and/or publisher system, upon receiving and reading the message, will simply remove the cached item from its cache.
Additional aspects of the system:

    
    
        The cache 140 (FIG. 4) illustrated above can be either in-memory or an on-disk data store (e.g. a database such as an IBM® DB2® database, flat file, binary file, binary encrypted file, etc).
        The broker system's cache engine 100 may attach an expiration for each key. This value could be used by the subscriber system's or publisher system's caches to invalidate cache entries. This may be useful to limit the growth of the cache.
        The broker system could send a subsequent message (to both publisher systems and subscriber systems) that would invalidate certain cache entries (e.g., it determines that data will never be used again).
        The broker system's cache engine 100 can support automatic cache creation as described earlier. For example, if the last “N” number of messages on a topic contains a common data segment, then that data segment should be marked for caching and a cache key/data pair created and sent with the next message.

Illustrative Implementations

Illustrative Implementation I

    
    


The cache engine either deletes or substitutes the cached data with the appropriate cache key/unique identifier (the system that allows for the data to be deleted is described below). For example, assume that the message being sent appears as follows:

    
    
        AAAAAABBBBBBBCCCCCCDDDDDDEEEEEEE
    
    


The cache engine states that the “B's” will likely be used in future messages and instructs recipients that they should retain that portion in their local cache. In this example, the portion of data BBBBBBB will be referred to as  ̃rp1. The recipient will store the portion BBBBBBB and analyze incoming messages for the presence of  ̃rp1. Further assume that at some future point in time, a publisher wants to send a message that appears as follows:

    
    
        FFFFFFFFBBBBBBBUUUUUUJJJJJJJJ
    
    


Rather than sending this message, it can now send the following:

    
    
        FFFFFFFF ̃rp1UUUUUUJJJJJJJJ
    
    


This allows for the sender to send less traffic on the network. Upon receipt of this message, the recipient will then reconstruct the message based on translation information from its cache and create the following message:

    
    
        FFFFFFFFBBBBBBBUUUUUUJJJJJJJJ

after expanding  ̃rp1 to BBBBBBB.

Illustrative Implementation II

    
    


If it was desired for cached data to be inserted at the 12th position of the message, for example, the message and a property/attribute (or custom header) would be generated that indicates rp1=12,x,y (where rp1is the cache key/unique identifier, and 12 is the first position to insert the data, x is the next, y is the next, and so on). This method obviates the need to delete any un-cached message data that matches a cache indicator.
It is noted that multiple approaches may be included in these solutions.
Automatic Selection of Cache Data: In a typical embodiment, the proposed invention automatically determines which information should be cached.
Several techniques may be used to identify cacheable information. The techniques identified below may be used independently or in conjunction with each other.
Differencing Engine: This system analyzes messages either within a single topic, or across multiple topics capturing the similarities between messages. The most similar aspects of the messages are presumed good candidates for future caching. The similarities captured may be persisted across restarts such that caching efficiency is not interrupted. The items cached may change over time as the message profiles change. For example, if one type of message is dominant for a while, then a second disparate message type is dominant. Over time, cache entries related to the first type may be invalidated to make room for the second type.
Rate-Based Selection: It is common for some messages and topics to have a higher rate of publishing than others. This rate may be related to the importance or the dynamic nature of the subject for each particular topic. Topics with a higher publication rate should be selected for caching before topics with a lower publication rate. Rate-based selection counts the total number of messages per topic, or message types within a single topic, and selects the most published topics or message types for message portion caching.
Message Correlation Selection: Such a system may determine correlations between related topics and therefore cache the potential similarities for the related topics upon detection of the first message. For example, there may be related topics of /scores/[court]/ and /stats/[court] where court is a changing topic related to particular players on a particular cart. Every message published to a /stats/[court] is preceded by a message published to /scores/[court]. Both sets of messages may identify the player names for that particular court. Therefore, this method may discern that for every message published to /scores/[court] and /stats/[court], while components of the message change (current score, current stats), the player names stay the same. Therefore, for a short period of time after a message is published to /scores/[court] the player name component is eligible for caching until the corresponding /stats/[court] message is sent.
Finally, it is noted that different methods of signifying data entities may be used by both senders and recipients of data. These include universal hashing, hashing with checksums, rolling hashes, or even cryptographic hash functions, should security dictate. Each of these approaches offers certain advantages and can be used to speed and ease the implementation of any concepts described herein.
Referring now to FIG. 5, a method flow diagram according to an embodiment of the present invention is shown. In step T1, P2P communication is established between a set of publisher systems in the pub/sub messaging environment. In step T2, a set of data that is common to the set of publisher systems having a potential to be cached is identified. In step T3, a unique identifier corresponding to the set of data is generated on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable. In step T4, the unique identifier is shared among the set of publisher systems. In step T5, the set of data is associated with the unique identifier. In step T6, a first message having the set of data and the unique identifier is (generated and) sent to the broker system in the pub/sub messaging environment.
Referring now to FIG. 6, the retrieval of previously cached data will be described in greater detail. In step V1, a second message (as opposed to the first message of step T6 of FIG. 5) is generated on the publisher system. In this instance, the second message will have the unique identifier in place of a set of data that was previously cached. In step V2, the second message is sent to the broker system as an abbreviated message. In step V3, the unique identifier is located in the second message. In step V4, the set of data is retrieved from the cache, and used to replace the unique identifier in the second message in step V5. Then, in step V6, the second message is sent from the broker system to a set of subscriber systems. Alternatively, the abbreviated message received by the broker system could be sent to the subscriber system(s) which the subscriber system(s) could then utilize to retrieve the data from cache to complete the message. This option would occur where the subscriber system(s) have access to previously cached data.
While shown and described herein as a data caching solution, it is understood that the invention further provides various alternative embodiments. For example, in one embodiment, the invention provides a computer-readable/useable medium that includes computer program code to enable a computer infrastructure to provide data caching functionality as discussed herein. To this extent, the computer-readable/useable medium includes program code that implements each of the various processes of the invention. It is understood that the terms computer-readable medium or computer-useable medium comprise one or more of any type of physical embodiment of the program code. In particular, the computer-readable/useable medium can comprise program code embodied on one or more portable storage articles of manufacture (e.g., a compact disc, a magnetic disk, a tape, etc.), on one or more data storage portions of a computing device, such as memory 28 (FIG. 1) and/or storage system 34 (FIG. 1) (e.g., a fixed disk, a read-only memory, a random access memory, a cache memory, etc.).
In another embodiment, the invention provides a method that performs the process of the invention on a subscription, advertising, and/or fee basis. That is, a service provider, such as a Solution Integrator, could offer to provide data caching functionality. In this case, the service provider can create, maintain, support, etc., a computer infrastructure, such as computer system 12 (FIG. 1) that performs the processes of the invention for one or more consumers. In return, the service provider can receive payment from the consumer(s) under a subscription and/or fee agreement and/or the service provider can receive payment from the sale of advertising content to one or more third parties.
In still another embodiment, the invention provides a computer-implemented method for providing data caching functionality. In this case, a computer infrastructure, such as computer system 12 (FIG. 1), can be provided and one or more systems for performing the processes of the invention can be obtained (e.g., created, purchased, used, modified, etc.) and deployed to the computer infrastructure. To this extent, the deployment of a system can comprise one or more of: (1) installing program code on a computing device, such as computer system 12 (FIG. 1), from a computer-readable medium; (2) adding one or more computing devices to the computer infrastructure; and (3) incorporating and/or modifying one or more existing systems of the computer infrastructure to enable the computer infrastructure to perform the processes of the invention.
As used herein, it is understood that the terms “program code” and “computer program code” are synonymous and mean any expression, in any language, code, or notation, of a set of instructions intended to cause a computing device 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; and/or (b) reproduction in a different material form. To this extent, program code can be embodied as one or more of: an application/software program, component software/a library of functions, an operating system, a basic device system/driver for a particular computing device, and the like.
A data processing system suitable for storing and/or executing program code can be provided hereunder and can include at least one processor communicatively coupled, directly or indirectly, to memory elements through a system bus. The memory elements can include, but are not limited to, local memory employed during actual execution of the program code, bulk storage, and cache memories that provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. Input/output and/or other external devices (including, but not limited to, keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening device controllers.
Network adapters also may be coupled to the system to enable the data processing system to become coupled to other data processing systems, remote printers, storage devices, and/or the like, through any combination of intervening private or public networks. Illustrative network adapters include, but are not limited to, modems, cable modems, and Ethernet cards.
The foregoing description of various aspects of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed and, obviously, many modifications and variations are possible. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of the invention as defined by the accompanying claims.

## Claims

1. A method for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, comprising:
identifying a set of publisher systems as a peer group in the pub/sub messaging environment;
establishing P2P communication between the set of publisher systems of the peer group in the pub/sub messaging environment;
detecting that a set of data has occurred a first predetermined number of times;
in response to the detecting, determining whether the data has occurred among the peer group a second predetermined number of times;
in response to the determining, identifying a set of data having a potential to be cached;
generating a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable;
sharing the unique identifier among the set of publisher systems;
associating the set of data with the unique identifier;
sending a first message having the set of data and the unique identifier to a broker system in the pub/sub messaging environment;
receiving the first message on the broker system;
locating the unique identifier;
causing the set of data to be stored in a cache;
sending the first message to a set of subscriber systems in the pub/sub messaging environment;
receiving a second message on the broker system from any of the set of publisher systems, the second message comprising an abbreviated message having the unique identifier in place of the set of data;
locating the unique identifier in the abbreviated message;
retrieving the set of data from the cache;
replacing the unique identifier with the set of data in the second message to yield a completed message; and
sending the completed message to the set of subscriber systems.

2. The method of claim 1, the associating and the sending being performed by the at least one of the set of publisher systems.

3. The method of claim 1, the cache being a broker system cache.

4. The method of claim 1, the identifying a set of publisher systems further comprising reading configuration data to identify the set of publisher systems as the peer group in the pub/sub messaging environment.

5. The method of claim 1, further comprising defining a master peer or some other hierarchy for managing communications between the peer group.

6. The method of claim 1, wherein a service solution provider provides a computer infrastructure that performs the method for one or more consumers.

7. A system for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, comprising:
at least one bus;
at least one processor coupled to the at least one bus; and
at least one memory medium coupled to the at least one bus, the at least one memory medium comprising instructions to:
identify a set of publisher systems as a peer group in the pub/sub messaging environment;
establish P2P communication between the set of publisher systems of the peer group in the pub/sub messaging environment;
detect that a set of data has occurred a first predetermined number of times;
in response to the detecting, determine whether the data has occurred among the peer group a second predetermined number of times;
in response to the determining, identify a set of data having a potential to be cached;
generate a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable;
share the unique identifier among the set of publisher systems;
associate the set of data with the unique identifier;
send a first message having the set of data and the unique identifier to a broker system in the messaging pub/sub environment;
receive the first message on the broker system;
locate the unique identifier;
cause the set of data to be stored in a cache;
send the first message to a set of subscriber systems in the pub/sub messaging environment;
receive a second message on the broker system from any of the set of publisher systems, the second message comprising an abbreviated message having the unique identifier in place of the set of data;
locate the unique identifier in the abbreviated message;
retrieve the set of data from the cache;
replace the unique identifier with the set of data in the second message to yield a completed message; and
send the completed message to the set of subscriber systems.

8. The system of claim 7, the cache being a broker system cache.

9. The system of claim 7, the at least one memory medium further comprising instructions to:
receive an invalidation message from the publisher system; and
remove a set of items from the cache based on the invalidation message.

10. The system of claim 7, the memory medium further comprising instructions to define at least one of a master peer or a hierarchy for managing communications between the peer group.

11. At least one computer program product for establishing peer-to-peer (P2P) collaboration of publishers in a publish-subscription (pub/sub) messaging environment, the at least one computer program product comprising at least one computer readable hardware storage device, and program instructions stored on the at least one computer readable storage media, to:
identify a set of publisher systems as a peer group in the pub/sub messaging environment;
establish P2P communication between the set of publisher systems of the peer group in the pub/sub messaging environment;
detect that a set of data has occurred a first predetermined number of times;
in response to the detection, determine whether the data has occurred among the peer group a second predetermined number of times;
in response to the determining, identify a set of data having a potential to be cached;
generate a unique identifier corresponding to the set of data on at least one of the set of publisher systems, the unique identifier identifying the set of data as cacheable;
share the unique identifier among the set of publisher systems;
associate the set of data with the unique identifier;
send a first message having the set of data and the unique identifier to a broker system in the pub/sub messaging environment;
receive the first message on the broker system;
locate the unique identifier;
cause the set of data to be stored in a cache;
send the first message to a set of subscriber systems in the pub/sub messaging environment;
receive a second message on the broker system from any of the set of publisher systems, the second message comprising an abbreviated message having the unique identifier in place of the set of data;
locate the unique identifier in the abbreviated message;
retrieve the set of data from the cache;
replace the unique identifier with the set of data in the second message to yield a completed message; and
send the completed message to the set of subscriber systems.

12. The at least one computer program product of claim 11, the cache being a broker system cache.

13. The at least one computer program product of claim 11, further comprising program instructions stored on the at least one computer readable hardware storage device to:
receive an invalidation message from the publisher system; and
remove a set of items from the cache based on the invalidation message.

14. The at least one computer program product of claim 11, further comprising program instructions storied on the at least one computer readable hardware storage device to: define at least one of a master peer or a hierarchy for managing communications between the peer group.