Apparatus and method for providing decoupling of data exchange details for providing high performance communication between software processes

• US 5,557,798 A
• Filed: 12/21/1990
• Issued: 09/17/1996
• Est. Priority Date: 07/27/1989
• Status: Expired due to Term

• Current Assignee: Thomson Reuters Global Resources Unlimited Company (The Woodbridge Co. Ltd.)
• Original Assignee: TIBCO Software Incorporated (Cloud Software Group)
• Inventors: Bowles, Mark, Skeen, Marion D.
• Primary Examiner(s): Kriess, Kevin A.
• Application Number:
  US07/632,551
• Time in Patent Office: 2,097 Days
• Field of Search: 395/650, 395/700
• US Class Current: 705/35
• CPC Class Codes: G06F 3/0481 based on specific properties of the displayed interaction object or a metaphor-based environment, e.g. interaction with desktop elements like windows or icons, or assisted by a cursor's changing behaviour or appearance
• CPC Class Codes: G06F 9/45512 Command shells
• CPC Class Codes: G06F 9/465 Distributed object oriented systems remote method invocation [RMI] G06F9/548
• CPC Class Codes: G06F 9/542 Event management; Broadcasting; Multicasting; Notifications
• CPC Class Codes: G06Q 40/00 Finance; Insurance; Tax strategies; Processing of corporate or income taxes
• CPC Class Codes: G06Q 40/04 Trading; Exchange, e.g. stocks, commodities, derivatives or currency exchange
• CPC Class Codes: H04L 12/1804 for stock exchange and similar applications
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04M 15/68 Payment of value-added services
• CPC Class Codes: H04M 2215/0196 Payment of value-added services, mainly when their charges are added on the telephone bill, e.g. payment of non-telecom services, e-commerce, on-line banking

Abstract

A communication interface for decoupling one software application from another software application such communications between applications are facilitated and applications may be developed in modularized fashion. The communication interface is comprised of two libraries of programs. One library manages self-describing forms which contain actual data to be exchanged as well as type information regarding data format and class definition that contain semantic information. Another library manages communications and includes a subject mapper to receive subscription requests regarding a particular subject and map them to particular communication disciplines and to particular services supplying this information. A number of communication disciplines also cooperate with the subject mapper or directly with client applications to manage communications with various other applications using the communication protocols used by those other applications.

Claims

1. In a distributed computing environment including one or more computers coupled together by one or more networks, said one or more computers having in execution thereon one or more subscriber applications each of which has the capability of making a subscription request requesting that data on one or more subjects be sent to said subscriber application whenever data on said subject becomes available until said subscription is canceled, and said one or more computers having in execution thereon one or more service applications, each of which is capable of transmitting over said one or more networks data on one or more subjects, an apparatus comprising:

intermediary software controlling said one or more computers and coupled to said one or more networks and said one or more subscriber and service applications, so as to logically decouple said one or more subscriber applications from said service applications in the sense of performing all necessary functions to get data requested by subject by said subscriber applications from one or more service applications that supply data on the requested subject to all computers on which a subscriber application is in execution which has an open subscription to the subject of said data and from each such computer to the subscribing applications themselves and delivering said data only to said computers on which there is in execution a subscriber application having an open subscription to the subject of said data, said logical decoupling also implemented by said intermediary software by eliminating the need to have computer code in any said service application which outputs any data, other than the subject itself, which controls where in said distributed computing environment data published by said service application in execution on one or more of said computers is distributed or which identifies or locates any subscriber application or computer in said distributed computing environment to which data published by any said service application is to be distributed, and by eliminating the need for any subscriber application to include computer code which identifies any particular service application from which data is to be sought or which can find a service application which can supply data on a subject desired by said subscriber application, said intermediary software for controlling said one or more computers so as to automatically set up a communication path through said network between service applications which publish data on a subject and all and only computers having in execution thereon subscriber applications having an open subscription to the subject of said data.

2. An apparatus for use in a distributed computing system comprised of one or more computers some of which may be clients and some of which may be servers and some of which may be both clients and servers, all said computers coupled by a network or data path, said apparatus for interfacing at least one application process in execution on at least one client computer having an operating system embodying a transport layer communication protocol and a network interface circuit card coupling the client computer to said network to which is coupled at least one server computer having an operating system embodying a transport layer protocol and execution of which is controlled by at least one service process, such that said at least one application process requesting data on a subject can be selectively linked to at least one service process which is capable of supplying data on said subject using a subscription paradigm, and wherein each said at least one application process is capable of issuing subscription requests requesting an ongoing flow of data on the subject named in each said subscription request whenever said data is published, comprising:

communication means including at least one protocol engine for execution on each of said host and server computers and coupled to said transport layer communication protocols of said host and server computers, each protocol engine encapsulating a communication protocol providing reliability or efficiency enhancing functions not supplied by said transpod layer communication protocol, said protocol engines for exchanging data with each other over said network, said communication means for receiving a link request to set up a subscription-based data communication link to a selected server computer and for selecting and invoking selected ones of said protocol engines encapsulating a desired communication protocol and for invoking said transport layer communication protocol to physically establish said data communication link;

service means for processing subscription requests, said service means including at least two service discipline(s) including a consumer side service discipline program for controlling one or more of said computers so as to communicate with said at least one application process and a publisher side service discipline program for controlling one or more of said computers so as to communicate with said at least one service process and which is capable of receiving data published on a subject by said service process and distributing said published data to only those computers having in execution thereon an application process having an open subscription to the subject of said data, said data published by said service process containing no data indicating where said data is to be sent within said distributed computing system, other than the subject of the published data itself, said service means for transmitting said data to all application processes which have issued subscription requests naming the subject of said data as being of interest, and wherein at least said consumer side service discipline encapsulates a communication protocol for communicating to at least a selected one of said services via the publisher side service discipline coupled thereto, said service means for receiving a subscription link request requesting establishment of a subscription communication link with one or more of said service processes named in said subscription communication link which publishes data on a particular subject and for generating and transmitting to said communication means said link request requesting the establishment by said communication means of said subscription-based data communication link with the service identified in said subscription link request, and for sending a subscription registration message to said publisher side service discipline coupled to said one or more service processes requesting that all data on said subject, whenever published, be sent to each said application process(es) which has issued a subscription request on the subject so long as said subscription has not been canceled, said publisher side service discipline being selectively coupled to said service process for registering said subscription in a subscription list identifying at least all application processes that have active subscriptions and the subjects thereof, at least one of said service disciplines being coupled to each said application and services process for which an active subscription and communication link have been established and cooperating with each said application process that issued a subscription request and at least one said service process that is capable of supplying data on the subject so as to forward data published by said service process(es)on the subject of an active subscription to all said application processes having an active subscription on said subject, said service means for filtering said published data by subject on the service side of the data communication link such that data published by said service process which does not correspond to the subject of any active subscription is not transmitted over the network but such that data having a subject matching the subject of an active subscription reaches all application processes which have active subscriptions on the subject; and

information means for controlling one or more computers so as to present a programmatic interface at least to said one or more application processes and said at least one service processes such said one or more application processes can open a subscription to a subject simply by passing a subscribe request to said programmatic interface and passing a subject thereto in said subscription request and such that a service process can publish data on a subject to all said application processes having an open subscription to said subject simply by invoking a publish function of said programmatic interface and passing the data to be published thereto along with a subject of said data, said information means for receiving said subscribe request(s) from said one or more application process(es), each said subscribe request containing at least a subject and the identity of a callback routine for said application process, and, for each said subscribe request, mapping said subject contained therein to one or more of said service processes which can supply data on said subject and at least a selected one of said service disciplines which encapsulates a communication protocol capable of communicating with said selected service or services, and for transmitting the subject of said subscribe request to said service means along with data identifying and/or giving the address in said distributed computing system of at least one service process with which subscription based data communication links are to be established.

3. The apparatus of claim 2 wherein data transmitted between said application process and said service process is transmitted over said data path or network as a data message comprising a plurality of sequential packets, each of which has a header and error corrections bits as part of said packet, and wherein said communication means further comprises:

a memory;

means for adding reliability enhancing sequence numbers to said packet headers prior to transmission;

means for transmitting over said data path or network the packets, error correction bits and sequence numbers which comprise a complete data message;

means for saving said packets in said memory with said sequence numbers and error correction bits in case some or all of the packets need to be retransmitted;

means for transmitting said packets;

means for receiving said packets and checking said reliability sequence numbers to determine that all packets have arrived and using said error correction bits to determine if any of said packets were garbled during transmission, and for requesting retransmission of any missing or garbled packets, or acknowledging that all packets were properly received; and

means for retransmitting any missing or garbled packets and for flushing any packets no longer needed from said memory.

4. In a distributed computing environment including at least one data consuming process in execution on one or more computers and at least one data producing process in execution on one or more computers, said one or more computers and said data consuming and data producing processes coupled by at least one data path and/or network, an apparatus comprising:

one or more computers in said distributed computing environment processing of which is controlled by one or more subject based addressing programs, said one or more subject based addressing programs for controlling said one or more computers to receive a subscription request from one or more data consuming processes to locate and access data on a specified subject, and for controlling said one or more computers to automatically locate at least one data producing process which produces data on said subject and for controlling said one or more computers to automatically generate each of said one or more link requests requesting that one or more subscription communication links be established over said data path between at least one of said data producing processes which supply data on the subject of said subscription request and at least one of said data consuming processes which made subscription requests for data on said subject; and

one or more computers in said distributed computing environment controlled by one or more communication programs to receive said link requests from said one or more computers controlled by said subject based addressing programs, and for controlling said one or more computers so as to automatically establish said one or more subscription communication links over said data path, each of said one or more subscription communication links being established using a communication protocol appropriate for communication with the data producing process with which said subscription communication link is established, said one or more subscription communication links being established by controlling said one or more computers controlled by said one or more communication programs such that there is no need for said one or more computers controlled by said one or more communication programs to receive any address or address related data, other than the subject itself of the subscription request, from any data consuming process indicating where in said distributed computing environment a data producing process which is publishing data on the subject may be found and by controlling said one or more computers controlled by said one or more communication programs such that there is no need to receive any data from any data producing process, other than the subject itself of the data published by said data producing process, indicating or controlling where the data published by the data producing process is to be sent in said distributed computing environment, said one or more communication programs also for controlling said one or more computers so as to automatically transport data published on the subjects of any active subscription(s) to all but only said one or more computers processing of which is controlled by a data consuming processes which issued a subscription request requesting data on said subject and for controlling said one or more computers so as to automatically route said data published on a subject for which there is an active subscription to all said one or more data consuming processes having an active subscription on the subject of said data until said subscription(s) is canceled.

5. The apparatus of claim 4 wherein said subject based addressing program includes directory services means for storing data identifying which data producing processes supply data on which subjects and for searching said data in response to receipt of a subscription request and returning any data located during said search identifying or giving the address in said distributed computing environment of one or more data producing processes which can supply data on the subject of said subscription request to said one or more computers controlled by said one or more subject based addressing programs for use in generating said one or more link requests.

6. The apparatus of claim 4 wherein each said subject can have multiple parts which are arranged into a subject space containing 30 or more multiple part subjects, and wherein said subject space is arranged hierarchically based upon said multiple parts of said subjects, and wherein said one or more computers controlled by said one or more subject based addressing programs include means for locating all data producing processes which publish data having a subject which satisfies all parts of said multiple part subject.

7. The apparatus of claim 4 wherein said subject contained within said subscription request can have multiple pads, and wherein each said multiple part subject can include empty strings or other wild card notations, and wherein said one or more computers controlled by said one or more subject based addressing programs includes means for locating all data producing processes which supply data having a subject which satisfies all parts of said multiple part subject which are not empty strings or wild card notations, and wherein no data producing process controlling any of said one or more computers so as to publish data on one or more subjects includes any software routine, program or data the content of which is dependent upon the existence or location in said distributed computing environment of any data consuming process which can issue subscription request or the purpose of which is to directly or indirectly locate any data consuming process which can issue subscription request, and wherein no data producing process controlling any of said one or more computers so as to publish data on one or more subjects includes any software routine, program or subroutine which functions to assist in any way, other than outputting the subject of published data, in routing data between any said data producing process which controls said one or more computers so as to publish data and any data consuming process controlling one or more computers, and wherein no data consuming process controlling one or more computers includes any software routine, program or the content of which is dependent upon the existence or location of any data producing process or the purpose of which is to control one or more of said computers so as to locate any data producing process other than by outputting the subject itself of the subscription request.

8. The apparatus of claim 6 wherein said multiple parts of said subject are hierarchically arranged, and wherein there are at least 30 data producing and data consuming processes controlling processing by one or more of said computers in said distributed computing environment.

9. The apparatus of claim 7 wherein said multiple pads of said subject are hierarchically arranged.

10. The apparatus of claim 5 wherein said one or more communication programs include means coupled to each of said one or more computers under control of one or more of said data producing processes for keeping a subscription list of all of said one or more data consuming processes which have requested subscriptions and the subjects of said subscriptions and for filtering data published by said one or more computers under control of said one or more data publishing processes such that only data having a subject which matches the subject of an active subscription is transmitted over said network or data path.

11. The apparatus of claim 6 wherein each said computer under control of one of said communication programs further comprise means coupled to each data consuming process and each data producing process via the one or more computers controlled thereby for keeping a list indicating for each subject whether there are or are not active subscriptions for that subject, and wherein each said computer under control of one of said communication programs further comprises means for checking said list each time a data message on any subject is published by one or more computers under control of one or more of said data producing processes and for broadcasting over said data path or network each data message published by one or more computers under control of any data producing process on a subject for which there is at least one active subscription indicated on said list, and each said computer under control of at least one of said communication programs further comprising a communication daemon means for controlling execution by each said computer by multitasking so as to cause each said computer under control of at least one of said communications means to filter incoming data messages by subject so that data messages on any subject for which there is an active subscription entered by a data consuming process controlling processing in a multitasking environment on one of said computers on which a communication daemon means is also controlling execution of said computer on a multitasking basis are automatically sent to all data consuming processes in execution on said computer that requested said data and all other data messages on subjects for which there are no active subscriptions by any data consuming process controlling execution of said computer on a multitasking basis are discarded.

12. The apparatus of claim 8 wherein said one or more computers under control of said one or more communication programs further comprises means coupled to each data consuming process for filtering incoming data by subject so that only data on the requested subject reaches the data consuming process which requested said data.

13. The apparatus of claim 4 further comprising a distributed communications component comprised of one or more computers controlled by one or more computer programs to receive instructions from said one or more computers controlled by one or more subject based addressing programs to establish communications with one or more computers controlled by one or more data publishing computer programs, said distributed communications component for shielding said application and data publishing computer programs from the need to have routines or computer instructions therein to control said one or more computers so as to be able to know the physical distribution of other computers and computer programs in said distributed system and the communication processes so as to be able to communicate with said other computers and computer programs thereby insulating said application and data publishing computer programs from having dependencies on various characteristics of said distributed system designed into the computer programming instructions of said application and data publishing computer programs which could render said application and data publishing computer programs obsolete when said characteristics of said distributed system change.

14. In a computing environment having one or more computers coupled by one or more data paths and/or one or more networks, and having one or more data producing processes which publish data messages on one or more subjects arranged into a subject space, and one or more data consuming processes which need data on one or more subjects, said one or more data producing processes and said one or more data consuming processes in execution on said one or more computers, a process comprising the steps of:

storing data encoding the subjects in said subject space in a memory or other means for storing data coupled to of one or more of said computers, and storing in said memory or said other means for storing data mapping data which maps the identity and/or the address in said computing environment of one or more of said data producing processes for execution on one or more of said computers in said distributed computing system which can supply data on a subject for one or more subjects in said subject space;

receiving a subscription request from one or more data consuming processes for data on a particular subject and automatically locating all data producing processes which can supply data messages on that subject by using the subject of said subscription request to search said mapping data to locate a data producing process which can supply data on that subject without any assistance from said one or more data consuming processes other than receipt of the subject of the subscription request, and generating a link request, said link request directly or indirectly identifying said at least one data producing process located by search of said mapping data which can supply data on the requested subject included in said subscription request, said link request requesting that a communication link be established between at least one of said data producing processes identified in said link request and all of said data consuming processes which requested data on said subject; and

receiving said link request and automatically setting up a communications link with said at least one data producing process identified directly or indirectly in said link request, and directing data messages received from any said data producing process on said subject to all and only computers having their processing controlled by said data consuming processes which requested data on said subject without receiving any data from any said data producing process which publishes a data message, other than the subject of the data itself, which indicates or controls to which computers in said computing environment any said data message is to be sent,

and wherein no data producing process needs to include any data or computer instructions the purpose of which is to identify or locate any said data consuming process other than to output the subject of the data message being published.

15. The process of claim 14 wherein said step of automatically setting up said communications link further comprises the step of sending a request for a subscription to said at least one data producing process identified in said link request, said subscription request identifying directly or indirectly the data consuming process or processes which requested data on said subject, and wherein said step of directing data messages published by said data producing process on each said subject includes the step of directing all data messages published by said at least one data producing process to all data consuming processes which have an active subscription for data on said subject, said directing of data messages on a subject to all data consuming processes having active subscriptions for data on said subject occurring continuously each time a data message on said subject is published but not transmitting any message on any subject to any computer in said communication environment not having in execution thereon a data consuming process having an active subscription to the subject of said message, but ceasing to direct data messages to any data consuming process which has canceled its subscription.

16. The process of claim 14 wherein the step of locating all data producing processes which can supply data messages on the subject of a subscription request includes the steps of passing the subject of said subscription request to said one or more computers controlled by said directory services program which causes said one or more computers controlled by said directory services program to search said mapping data in said data stored in said computer memory encoding said subject space to locate the subject of said subscription request and return data identifying and/or giving the address in said computing environment of at least one data producing process which can supply data on the subject if any such process exists, and wherein said data returned by said computer controlled by said directory services programs is used to generate said link request, and wherein the step of automatically setting up a communications link further comprises the step of making one or more subscription lists listing subjects for which there are active subscriptions, said one or more subscription lists directly or indirectly identifying the data consuming processes that initiated the active subscriptions, and wherein the step of directing data messages on a subject to all data consuming processes which requested data on said subject further comprises the steps of comparing the subject of each data message published by any data publishing process to the subjects having active subscriptions listed on said one or more subscription lists and directing any data message published on a subject for which there is an active subscription to all data consuming processes that requested data on the subject of said data message, but not allowing any data message published by said data producing processes which does not match the subject of at least one active subscription to be transmitted over said data path.

17. The process of claim 14 wherein data messages transmitted between said data producing processes and said data consuming processes, hereafter referred to as processes, are transmitted as self describing data objects, wherein each self describing data object is comprised of one or more fields each of which is either a primitive class form which stores data or a constructed class form which is comprised of other fields which themselves may be primitive or constructed class forms, each said constructed class form belonging to a class which has a corresponding class definition, said self describing data objects being organized into classes defined by class definitions, each class definition comprising a list of the fields by name and data representation type which are common to all self describing data objects of that class, each self describing data object including both data format information and actual data or field values for each said field, and further comprising the steps of:

automatically converting any self describing data objects to be transmitted from one process to another from the format of the transmitting process to the format necessary for transmission across said data path prior to transmission thereof, and then transmitting said self describing data object through said data path; and

automatically converting any self describing data objects received after transmission through said data path which are bound for either a data consuming process or a data producing process, from the format used to transmit data across said data path to the format used by said receiving process.

18. The process of claim 17 wherein each said conversion step comprises the steps of:

receiving a format conversion call identifying the desired "from" format and the desired "to" format and identifying a specific self describing data object upon which the conversion is to be performed;

accessing a table storing identifiers of particular from-to format conversions;

locating the first field in said self describing data object which is a primitive class form;

using the format information stored in said self describing data object for the primitive field so located, looking up a "from" format in said table corresponding to the format of the primitive class field so located and determining the required "to" format for the conversion specified in said conversion call;

using a table storing pointers to appropriate conversion software routines for the desired from-to format conversion, looking up a from-to format conversion pointer using the "from" and "to" formats just determined and using said pointer to execute an appropriate software routine to perform the desired from-to format conversion;

locating the next field containing a primitive class form in the self describing data object identified in said conversion call and repeating the above steps to convert the data in the next primitive class form from the then existing "from" format to the desired "to" format and repeating this process until all fields containing primitive class forms have been so processed; and

processing every field containing a constructed class form as defined above by searching the constructed class form until the first field is found containing a primitive class form and converting the format thereof using the steps defined above and repeating this process until all fields containing primitive class forms for all levels of nesting of fields containing constructed class forms have been converted to the desired "to" format.

19. The process of claim 14 wherein data transmitted between said data producing processes and said data consuming processes is transmitted as self describing data objects, each self describing data object comprised of one or more fields each of which is either a primitive class form which stores data or a constructed class form which is comprised of other fields which themselves may be primitive or constructed class forms, each said constructed class form belonging to a class which has a corresponding class definition, said self describing data objects being organized into classes defined by class definitions, each class definition comprising a list of the fields by name and data representation type which are common to all self describing data objects of that class, each self describing data object including both data format information and actual data or field values for each said field, for providing the capability for a data consuming or data producing process to obtain data from a particular field of a particular self describing data object generated by another process, comprising the steps of:

receiving in a Get-Field call from a process that desires particular data, said Get-Field call identifying the particular field name of the field of the self describing data object from which the data is to be obtained and the particular one of said self describing data objects from which data is to be obtained;

searching the class definition for said self describing data object from which data is to be obtained to locate said field name identified in said Get-Field call or some synonym thereof;

returning a relative address for said field identified in said Get-Field call, said relative address identifying where in instances of said class of said self describing data object identified in said Get-Field call said field named in said Get-Field call can be found;

accessing said self describing data object identified in said Get-Field call and retrieving the desired data using said relative address of the field in which the desired data is stored, and returning the desired data to the process which requested said data.

20. The process of claim 14 wherein the step of automatically setting up a communications link further comprises the steps of:

sending a subscription request message to a publisher side service discipline process which controls one or more of said computers so as to be coupled to receive data on the subject of said subscription request from a data producing process or processes which control the same said one or more computers having said publisher side service discipline process in execution thereon so as to publish data messages on said subject and with which communication links are to be set up on said subject;

recording all said subscription requests in a subscription table or list;

assigning a channel on said one or more data paths and/or one or more networks to each said subject for which there is an active subscription and recording said channel in said subscription table for each;

when a data message is published by any said data producing process, checking the subject thereof against the subjects of all active subscriptions in said subscription table or list to determine if there are any active subscriptions on the subject;

sending said data message published by any data producing process to all data consuming processes having active subscriptions to the subject of said data by a broadcast communication protocol by dividing said data message into one or more sequential packets suitable for transmission over said data path and/or network, each sequential packet having a header and adding to said header the channel number assigned to said subject and a sequence number indicating where said packet lies in the sequence of packets which, taken together, comprise the data message published by said data publishing process, and calculating error correction bits on data within each said packet and adding said error correction bits so calculated to each said packet;

storing all said packets in a retransmit memory;

sending messages to each data consuming process having an active subscription to the subject of said data informing each data consuming process of the channel on which said data will be broadcast;

broadcasting said data packets on said channel assigned to the subject of said data via said data path and/or network;

receiving said packets at the location of each computer in said computing environment and, at the location of each said computer, comparing the channel number of each said packet so received to the channel numbers recorded in said subscription table of all active subscriptions initiated by any data consuming process in execution at the location of said computer;

if the channel number of the received packets at any computer in said computing environment matches the channel number of any active subscription recorded in said subscription table of a data consuming process in execution on said computer, checking the sequence numbers of all packets received at the location of said computer in said computing environment to determine if all packets comprising the complete data message have been received and using said error correction bits to determine if each received packet has been correctly received, and repeating this process at the location of each said computer, and if the channel number of the received packets at any computer in said computing environment does not match the channel number recorded in said subscription table of a data consuming process in execution on said computer, discarding all said packets whose channel numbers do not match the channel number recorded in said subscription table of a data consuming process in execution on said computer;

if all packets have been successfully received, sending a message back to the process that transmitted the data that all packets have been successfully received, or, if any packet was not received or was not correctly received, sending a message to the process that transmitted the data requesting retransmission of any packets which were not received or which were not correctly received and which cannot be corrected at the receiving computer using said error correction bits;

retransmitting any packets that were not received or which were not correctly received to any computer in said computing environment that transmitted a message indicating one or more packets were not received or were not received correctly;

verifying that the newly transmitted packets have been received and have been correctly received; and

reassembling said data packets into said data message at the location of any computer which received data packets having channel numbers matching the channel number of an active subscription entered by a data consuming process in execution on said computer, and passing said reassembled data message to the data consuming process or processes which requested data on the subject of said data message which is in execution on said computer.

21. The process of claim 14 wherein the step of setting up a communications link further comprises the steps of:

sending a subscription request message to a publisher side service discipline process which controls one or more of said computers so as to be coupled to receive data on the subject of said subscription request from a data producing process or processes which control the same said one or more computers having said publisher side service discipline process in execution thereon so as to publish data on the subject of said subscription request;

recording all said subscription requests in a subscription table and storing in said table the identities of all data consuming processes desiring data on each subject which is the subject of an active subscription;

assigning a channel on said one or more data paths and/or one or more networks to each said subject for which there is an active subscription and recording said channel in said subscription table for each said subscription recorded therein;

when data is published by any said data producing process with which a communication link has been established, checking the subject thereof against the subjects of all active subscriptions in said subscription table to determine how many data consuming processes have active subscriptions on the subject;

comparing the number of said data consuming processes to a predetermined threshold, and determining whether it would be more efficient to transmit the data to all data consuming processes having active subscriptions on said subject using a point-to-point communication protocol by sending the same data multiple times over said one or more data paths and/or one or more networks, one said point to point communication being addressed to each data consuming processes having an active subscription to the subject of said data or by broadcasting said data on a predetermined channel on said one or more data paths and/or one or more networks;

sending said data to all data consuming processes having active subscriptions to the subject of said data by said point-to-point communication protocol if said point-to-point communication protocol is most efficient;

sending said data to all data consuming processes having active subscriptions to the subject of said data by a broadcast communication protocol if said broadcast communication protocol is most efficient;

if said broadcast communication protocol is selected, dividing said data into one or more sequential packets suitable for transmission over a data path, each with a header and adding to said header the channel number assigned to said subject and a sequence number indicating where in the sequence of packets which, taken together, comprise the data message published by said data publishing process, and calculating error correction bits on each packet and adding said error correction bits to each said packet;

storing all said packets in a retransmit memory;

sending messages to each data consuming process having an active subscription to the subject of said data informing each data consuming process of the channel on which said data will be broadcast;

broadcasting on said one or more data paths and/or said one or more networks said data packets via said channel on said one or more data paths and/or one or more networks assigned to the subject of said data;

receiving said packets at each said computer in said computing environment and, at each said computer, comparing the channel number of each said packet to the channel numbers of all active subscriptions listed in said subscription table entered by a data consuming process in execution on said computer;

if the channel number of packets received at a computer in said computing environment matches the channel number of any active subscription listed in said subscription table entered by a data consuming process in execution on said computer, checking the sequence numbers of all packets received to determine if all packets have been received and using said error correction bits to determine if each packet has been correctly received and to correct any errors which can be corrected at the receiving computer using said error correction bits, and if the channel number of packets received at a computer in said computing environment does not match the channel number of any active subscription listed in said subscription table entered by a data consuming process in execution on said computer, discarding all such packets;

sending a message back to the process that transmitted said packets that all packets have been successfully received, or, if any packet was not received or was not correctly received, sending a message to the process that transmitted said packets requesting retransmission of any packets which were not received or which were not correctly received;

retransmitting any packets that were not received or which were not correctly received;

verifying that the newly transmitted packets have been received and have been correctly received; and

reassembling said data packets into a data message and passing the data packets to the data consuming process or processes which requested data on the subject.

22. The process of claim 17 wherein the step of setting up a communications link further comprises the steps of:

sending a subscription request message to a publisher side service discipline process which controls one or more of said computers so as to be coupled to receive data on the subject of said subscription request from a data producing process or processes with which communication links are to be set up on said subject and which control the same said one or more computers having said publisher side service discipline process in execution thereon;

recording all said subscription requests in a subscription table and storing in said table the identities or addresses of all data consuming processes desiring data on each subject which is the subject of an active subscription;

assigning a channel on said one or more data paths and/or one or more networks to each said subject for which there is an active subscription and recording said channel in said subscription table for each said subscription recorded therein;

when data is published by any said data producing process with which a communication link has been established, checking the subject thereof against the subjects of all active subscriptions in said subscription table to determine how many data consuming processes have active subscriptions on the subject;

comparing the number of said data consuming processes to a predetermined threshold, and determining whether it would be more efficient to transmit the data to all data consuming processes having active subscriptions on said subject using a point-to-point communication protocol by sending the same data multiple times over said one or more data paths and/or one or more networks, one said point to point communication being addressed to each data consuming processes having an active subscription to the subject of said data message or by broadcasting said data message on a predetermined channel on said one or more data paths and/or one or more networks and sending a message to all data consuming processes having active subscriptions on said subject to listen for data on the subject of said active subscriptions on said predetermined channel on said one or more data paths and/or one or more networks;

sending said data message to all data consuming processes having active subscriptions to the subject of said data by said point-to-point communication protocol if said point-to-point communication protocol is most efficient;

sending said data message to all data consuming processes having active subscriptions to the subject of said data message by a broadcast communication protocol if said broadcast communication protocol is most efficient;

if said broadcast communication protocol is selected, dividing said data message into one or more sequential packets suitable for transmission over a data path, each with a header and adding to said header the channel number assigned to said subject and a sequence number indicating where in the sequence of packets which, taken together, comprise the data published by said data publishing process, and calculating error correction bits and adding said error correction bits to each said packet;

storing all said packets in a retransmit memory;

broadcasting on said one or more data paths and/or said one or more networks said data packets on said channel on said one or more data paths and/or one or more networks assigned to the subject of said data;

receiving said packets at each said computer in said computing environment and, at each said computer, comparing the channel number to the channel numbers of all active subscriptions listed in said subscription table entered by a data consuming process in execution on said computer;

if the channel number of packets received at a computer in said computing environment of a packet matches the channel number of any active subscription, listed in said subscription table entered by a data consuming process in execution on said computer, checking the sequence numbers of all packets received to determine if all packets have been received and using said error correction bits to determine if each packet has been correctly received and to correct any errors which can be corrected at the receiving computer using said error correction bits, and if the channel number of packets received at a computer in said computing environment does not match the channel number of any active subscription listed in said subscription table entered by a data consuming process in execution on said computer, discarding all such packets;

sending a message back to the data producing process that all packets have been successfully received, or, if any packet was not received or was not correctly received, sending a message to the data producing process that published the data requesting retransmission of any packets which were not received or which were not correctly received;

retransmitting any packets that were not received or which were not correctly received;

verifying that the newly transmitted packets have been received and have been correctly received; and

reassembling the data packets into the original data message and passing the data message to the data consuming process or processes which requested data on the subject.

23. An apparatus for obtaining data requested by one or more data consuming processes in execution on one or more computers from one or more service instances in execution on one or more hosts or server computers, comprising:

one or more networks or other data paths for transporting data between processes running at various locations or addresses on said network(s), said transport of data being carried out on one or more appropriate communication paths through said network(s) or other data path(s), and according to one or more appropriate communication mechanisms or transport protocols;

one or more host and/or server computers coupled to said network(s), each having one or more network addresses, each host and/or server computer having an operating system and one or more other process(es), data consuming process(es) or service instance(s) in execution thereon, each of said operating system(s), process(es), data consuming process(es) or service instance(s) being programmed in any selected programming language, each said host and/or server computer having any selected machine architecture or type including any appropriate machine instruction set and any appropriate data representation format or type, each of said operating system(s), process(es) and/or service instance(s) having one or more appropriate communication, access and/or invocation protocol(s);

one or more computers having in execution thereon one or more data location and access programs which control processing by said one or more computers, said data location and access programs being coupled to said one or more data consuming process(es) and said one or more other process(es) and/or service instance(s), for receiving one or more requests for desired data from said one or more data consuming processes, said request defining the identity of the desired data by an identifier comprising one or more parts, said desired data having certain access requirements including but not limited to the particular communication path(s) through said network(s) or other data path(s) to said desired data, the transport protocol or protocols along said communication path(s) through said network(s) or other data path(s) to said desired data, the network address(es) of the host(s) and/or server computer(s) on which the process(es) publishing the desired data is or were in execution, the machine architecture(s) or type(s) or operating system(s) or the data representation format or type of the host(s) and/or server computer(s) upon which the process(es) publishing the desired data is or were in execution, the particular process(es) and/or service instance(s) or the programming language(s) of the particular process(es) and/or service instance(s) which is or were publishing said desired data, and the communication, access or invocation protocol(s) which must be invoked to communicate, access or invoke said process(es) or service instance(s) which is or were publishing said desired data or the transport protocol(s) or operating system or systems in execution on any of said host or server computers involved in accessing and transporting said desired data from the process(es) which publish or distribute said desired data to the data consuming process which requested said data, all of said access requirements uniquely defining the attributes of a communication mechanism between said data consuming process(es) desiring said data and said desired data itself, said request for said desired data and said data consuming process which made said request being independent of one or more of said access requirements or attributes including at least the identity and/or location of said one or more particular process(es) and/or service instance(s) that publish or distribute said requested data and said communication, access or invocation protocol or protocols needed to communicate with said one or more process(es) and/or service instance(s) that publish or distribute said requested data as well as the location or address of the one or more computer(s) being controlled by said one or more processes and/or service instance(s) that publish or distribute said requested data, said independence meaning that the data consuming process which requested said desired data need include no program, code or data the purpose of which is to satisfy any of said access requirements, said one or more computers processing of which is controlled by said one or more data location and access programs being controlled thereby so as to automatically satisfy all said access requirements so as to establish a communication path(s) to said desired data, access said data and return said data to said data consuming process(es) that requested said data, and wherein said one or more process(es) and/or service instance(s) that publish or distribute said requested data also do not include any program, code or data the purpose of which is to satisfy any said access requirement, other than to output the subject itself of the data being published, or the purpose of which is to direct where said data is to be transmitted or to assist in any other way in satisfying any other of said access requirements.

24. The apparatus of claim 23 wherein said one or more data location and access programs include one or more data format decoupling programs coupled to said one or more computers having in execution thereon said one or more data location and access programs, said one or more data format decoupling programs for providing data representation independence such that data may be effectively obtained by said one or more data consuming process(es) which requested said data regardless of the particular data representation format(s) or type(s) used by said one or more data consuming process(es) and whatever process(es) or service instance(s) which publish the requested data.

25. The apparatus of claim 24 wherein said one or more data format decoupling programs further comprise means coupled to said one or more data consuming process(es) and said one or more process(es) and/or service instance(s) which publish the requested data for creating, manipulating, storing and transmitting self-describing data objects which include not only data but also data representation format information within each instance of a self describing data object.

26. The apparatus of claim 23 wherein said one or more data location and access programs include one or more service discipline programs for encapsulating appropriate software routines for communicating with one or more of said process(es) and/or service instance(s) which publish said requested data in the communication, access and/or invocation protocol(s) native thereto.

27. The apparatus of claim 24 wherein said one or more computers having in execution thereon said one or more data location and access programs for receiving said request(s) for desired data also are programmed to implement one or more service discipline means for encapsulating and executing appropriate software routines for controlling one or more computers so as to communicate with one or more of said process(es) and/or service instance(s) which publish said requested data using the communication, access and/or invocation protocol(s) native thereto, and wherein said self-describing data objects are organized into classes, each of which has common attributes and a unique class identifier, and wherein each self describing data object has one or more fields, each field being either primitive in that the field stores data or constructed in that the field stores data which is the class identifier of another class of self describing data objects and the data from an instance from said other class.

28. The apparatus of claim 23 wherein said one or more data location and access programs includes Subject-Addressed Subscription Service means for controlling said one or more computers to implement a programmatic interface to said one or more data consuming and data publishing processes, said programmatic interface implementing a subscribe function which can be invoked by a data consuming process by outputting a a subscription request requesting data by identifier only, said data and all updates thereto published under said particular identifier by one or more of said process(es) and/or service instance(s), and for automatically establishing a communication path between at least one of said data consuming processes which requested said data by identifier only and at least one of said processes and/or service instances which publish said requested data having said identifier until said subscription request is canceled, said programmatic interface also for controlling one or more computers having one or more service instances in execution thereon such that service instance(es) can publish data simply by invoking a publish function of said programmatic interface and outputting the data and the identifier of the data, and wherein said computer(s) controlled by said programmatic interface will use the identifier of said published data to automatically route the data to only those computers having in execution thereon a data consuming process having an open subscription to data having said identifier and to no other computer, said programmatic interface also controlling one or more computers such that when said process(es) and/or service instance(s) publish updates to said requested data with an identifier, said identifier is used to transmit said updates automatically to said one or more data consuming processes which requested said data for which said communication path(s) has or have been established and to only those computers having in execution thereon data consuming processes having open subscriptions to data having said identifier until said subscription is canceled.

29. The apparatus of claim 25 wherein said self-describing data objects are organized into classes, each of which has common attributes and a unique class identifier, and wherein each self-describing data object has one or more fields, each field being either primitive in that the field stores data or constructed in that the field stores data which comprises the class identifier of another class of self-describing data objects and the data from an instance from said other class.

30. The apparatus of claim 28 wherein said one or more data location and access programs further further comprises means, coupled to said one or more data consuming processes which requested said data and said one or more process(es) and/or service instance(s) which publish said requested data, for creating, manipulating, storing and transmitting said requested data as self-describing data objects which include not only data but also said data representation format or type information within each instance of a data object.

31. The apparatus of claim 30 wherein said self-describing data objects are organized into classes, each of which has common attributes and a unique class identifier, and wherein each self-describing data object has one or more fields, each field being either primitive in that the field stores data or constructed in that the field stores data which comprises the class identifier of another class of self-describing data objects and the data from an instance from said other class.

32. The apparatus of claim 28 wherein said one or more data location and access programs include one or more service discipline means, each for controlling one or more of said computers for communicating with one or more of said processes and/or service instances which publish said requested data in the communication, access or invocation protocol(s) native thereto.

33. The apparatus of claim 31 wherein said one or more data location and access programs include one or more programs which control said one or more computers to implement one or more service discipline means, each for communicating with one or more of said processes and/or service instances which publish said requested data in the communication, access or invocation protocol(s) native thereto.

34. The apparatus of claim 28 wherein said one or more computers having in execution thereon said one or more data location and access programs also are programmed to also implement means for establishing said communication path by listening for data messages from any source arriving at one or more network pod address(es) associated with said one or more data consuming processes which requested said data and filtering out all data messages other than data messages which have said identifier associated with said requested data, and passing all said messages having said identifier of said requested data to any said one or more computers having in execution thereon said one or more data consuming process(es) which issued said request(s) for said data and for which said communication path has been established.

35. The apparatus of claim 28 wherein said one or more data location and access programs include one or more programs to control one or more of said computers so as to implement subscription registration means for establishing said communication path by sending a subscription registration message to register said subscription for said desired data with the one or more computers having in execution thereon said one or more data location and access programs which are coupled to said process(es) and/or service instances which publish said requested data, said subscription registration message including the identifier of the requested data, and wherein said at least one process and/or service instance which publishes said requested data is coupled to said one or more computers implementing said subscription registration means and wherein said one or more computers having in execution thereon said one or more data location and access programs is also programmed to implement means for transmitting data published by said at least one process and/or service instance which has an identifier which matches the identifier for requested data which is the subject of any active subscription registration to all the data consuming process(es) which registered a subscription to data having said identifier.

36. The apparatus of claim 32 wherein each said computer programmed to implement said one or more service discipline means is also programmed to implement means for failure recovery so as to be able to maintain the flow of data to said one or more data consuming process(es) which requested said data despite failure of said communication path, host and/or server computer(s) or process(es) and/or service instance(s) which is publishing said requested data.

37. The apparatus of claim 28 wherein said Subject-Addressed Subscription Service means includes service discipline means for controlling said one or more computers to carey out communication of data over said communication path to fulfill said subscription request using a communication protocol which is appropriate for the one or more processes and/or service instances which are supplying said data, and wherein said one or more data location and access programs include one or more programs for controlling said one or more computers to implement one or more protocol engines, said protocol engines for establishing said communication path(s) using the appropriate network or communication path transport protocols for the communication path through which said requested data is obtained and for interfacing said service discipline means to said network or communication path transport protocols.

38. The apparatus of claim 25 wherein said one or more data location and access programs include means for implementing one or more service disciplines for controlling said one or more computers to communicate with service instances in the communication, access or invocation protocol native thereto, and wherein said one or more data location and access programs coupled to said one or more other process(es) and/or service instance(s) and said one or more data consuming process(es) include protocol engine means for controlling one or more computers to receive requests from said service disciplines to establish a communication path through which said requested data may be obtained, and assisting said one or more computers controlled by said service disciplines so as to establish said communication path(s) by interfacing said one or more computers controlled by said one or more service disciplines to the appropriate network or communication path transport protocols for the communication path through which said requested data is to be obtained.

39. The apparatus of claim 37 wherein said protocol engines include means for controlling said one or more computers to carry out a reliable broadcast communication protocol.

40. The apparatus of claim 39 wherein each said protocol engine controls said one or more computers so as to have different fault tolerance characteristics not already implemented by said transport protocols.

41. The apparatus of claim 38 wherein said one or more computers controlled by said protocol engine means is is controlled so as to carry out a reliable broadcast communication protocol if the number of subscribers to data having a particular identifier is greater than a programmable number and is controlled to carry out a point-to-point communication protocol it the number of subscribers is less than said programmable number.

42. The apparatus of claim 41 wherein each said a protocol engine controls said one or more computers so as to have different fault tolerance characteristics.

43. The apparatus of claim 23 or 28 wherein said requested data is transported over said communication path using one or more data messages, and wherein said one or more data location and access programs includes means for transporting said requested data over said communication path using a reliable communication protocol which insures that all data messages were received without error.

44. The apparatus of claim 23 or 28 wherein said one or more data location and access programs includes reliable broadcast transmit means coupled to said process(es) and/or service instance(s) which publish said requested data, said reliable broadcast transmit means for dividing data messages into packets for transmission on said network and adding sequence numbers to said packets, and for calculating error correction bits for each packet and adding said error correction bits to said packets, and for temporarily storing packets to be transmitted over said network in a retransmit memory, and for broadcasting said packets over said network or communication path, and wherein said one or more data location and access programs further comprise receive means coupled to said data consuming processes which requested said data for listening to a network address associated with at least one of said data consuming processes which requested said data and selecting incoming packets which comprise a complete data message of said requested data and checking the sequence numbers of incoming packets to insure that all data messages comprising said requested data have been received, and for using said error correction bits of each packet to detect and correct errors in said received packets, and, if any data message was not received or contains errors not correctable using said error correction bits, for sending a message back to said reliable broadcast transmit means requesting retransmission from said retransmit memory of any data messages not received or not received correctly.

45. The apparatus of claim 23 or 28 wherein said one or more data location and access programs further comprises an intelligent multicast program for controlling one or more computers so as to determine how many data consuming processes have open subscriptions to data with a particular identifier and for controlling said one or more computers to broadcast data messages having said identifier when the number of data consuming processes requesting said data is greater than or equal to a predetermined number, and for sending said data messages directly to the data consuming process or processes which requested said data by a point-to-point communication protocol when the number of said data consuming processes which requested said data is below said predetermined number, said predetermined number selected such that the most efficient means of transporting said data is used in terms of consumption of network or communication path bandwidth and consumption of computing resources.

46. The apparatus of claims 23 or 28 wherein said one or more computers having in execution thereon said one or more data location and access programs are controlled thereby so as to implement means for checking the identifier of said requested data and the identity or identities of said data consuming processes which requested said data against a list of authorized identifiers associated with each of said one or more data consuming processes which requested said data, and for blocking access by any data consuming process to any requested data having an identifier not on the list of authorized identifiers for said data consuming process.

47. The apparatus of claim 23 or 28 wherein said one or more computers having in execution thereon one or more data location and access programs are also programmed by said one or data location and access programs to implement means for switching communication paths through said network or other data communication path upon failure of the selected communication path or other interruptions in the flow of data so as to maintain the flow of data to all data consuming processes having open subscriptions.

48. An apparatus for use in a distributed computing environment, comprising:

one or more computers coupled by one or more data paths, said one or more computers having in execution thereon one or more application processes controlling processing of said one or more computers, and wherein at least one of said application processes is a data consumer process needing data on one or more subjects and capable of outputting a subscription request for each subject for which data is desired, each said subscription request including a subject for which data is requested but wherein no data consumer process needs to include any routine which controls one more of said computers so as to output any information, address data or address related data indicating where said data may be found in said distributed computing environment other than outputting the subscription request and the subject thereof, and wherein at least one of said application processes is a data publisher process which outputs data messages on various subjects but which does not need to include any routine the purpose of which is to output any address or address related data, other than the subject itself, which indicates where said data messages are to be transmitted in said distributed computing environment or in any other way assist in the distribution of said data;

one or more computers processing of which is controlled by one or more directory services programs or routines so as to, when given a subject, access and search a data file, said data file storing data records mapping data publisher processes to subjects, each said data record containing a subject and identity and/or address data specifying, directly or indirectly, the address in said distributed computing environment of one or more sources of data messages on said subject, each said source obtaining said data messages on said subject from one or more data publisher processes in said distributed computing environment which publish data on said subject, and wherein each source on any particular subject comprises one or more computers controlled by one or more computer programs so as to receive messages from a data publisher process on the subject corresponding to said source and re-transmit said data messages on the subject to only those data consumer processes which have open subscriptions for data messages on the subject, said one or more directory services programs or routines for controlling said one or more computers so as to return any data record in said data file identifying and/or giving the address in said distributed computing environment of one or more sources which can output data on said subject that was originally passed to said one or more computers on which said one or more directory services programs or routines are in execution;

one or more computers controlled by one or more mapping programs or routines so as to receive each said subscription request from a computer on which a data consumer process is in execution, said subscription request identifying only a particular subject for which a subscription is requested, said one or more mapping programs or routines for controlling said one or more computers so as to map the subject of said subscription request directly or indirectly to the identity and/or address in said distributed computing environment of one or more sources which can output data messages on said subject, said mapping carried out by said one or more computers controlled by said one or more mapping programs or routines by passing the subject of said subscription request to said one or more computers controlled by said at least one directory services program or routine so as to cause said one or more computers controlled by said one or more directory services programs or routines to search said data file for a data record(s) identifying and/or giving the address in said distributed computing environment of one or more sources which output data on said subject and controlling said one or more computers on which said one or more mapping programs or routines are in execution to receive said data records resulting from said search, said one or more mapping programs for controlling said one or more computers so as to output at least said identity or address data in a link request requesting the establishment of a subscription communication link with said one or more sources identified in said data records resulting from said search;

one or more computers controlled by one or more subscription registration and communication programs or routines so as to receive said identity and/or address data in said link request from said one or more computers controlled by said one or more mapping programs or routines, said link request corresponding to at least one subject and a corresponding subscription request, said subscription registration and communication programs or routines for controlling said one or more computers so as to automatically establish a communication link with at least one source which outputs data on the subject to which said link request pertains via at least one said data path and automatically send a subscription registration message to said at least one source identified in said link request so as to notify said source of an open subscription on said subject, each said subscription registration message directly or indirectly identifying and/or giving the address in said distributed computing environment of the data consumer process which issued said subscription request on said subject through the computer on which said data consumer process is in execution or some other process which controls one or more computers to receive data messages on the subject of said subscription request on behalf of said data consumer process which requested the data and pass the data messages only to said one or more computers controlled by said data consumer process which requested said data, said one or more subscription registration and communication programs also for controlling said one or more computers so as to receive data messages on said subject whenever said data messages on said subject are output by said source with which said subscription communication link has been established and pass said data messages to said one or more computers being controlled by said data consumer process which requested data on the subject until said subscription is canceled;

one or more computers under control by one or more data distribution programs or routines so as to implement said one or more sources which output data on the subject of each said subscription request, said sources being selectively coupled to said one or more computers under control of said data consumer processes and selectively coupled to said one or more computers under control of said data publisher processes, said one or more computers under control of said one or more data distribution programs or routines for receiving data messages published by said one or more data publisher processes on one or more subjects, and for receiving said subscription registration messages requesting subscriptions on one or more subjects and for automatically sending each said data message over said subscription communication link only to computers having in execution thereon data consumer processes having active subscriptions to the subject of said data message, said data distribution programs or routines controlling said one or more computers to so distribute published data without receiving any data from the data publisher process, other than the subject itself of each data message, indicating where each said data message on any subject is to be sent, and for automatically continuing to transmit each new data message received from a computer controlled by a data publisher process on any subject to only data consumer processes having an active subscription to the subject of each said new data message until said subscription is canceled, each said data distribution program(s) or routine(s) containing no routines, computer program, subroutine or other computer programming code the purpose of which is to receive any data from said data publisher process, other than the subject of a data message itself, which controls where in said distributed computing environment any said data message on any subject is to be sent.

49. A process for communicating data between at least one publishing process and at least one consumer process in execution on one or more computers in a distributed computing system, said publishing and consumer processes coupled by a data path, comprising:

storing data encoding a subject space and the subjects therein in a memory of one or more of said computers, and storing in said memory data mapping the identity and/or the address in said distributed computing system of one or more source computer processes for execution on one or more of said computers in said distributed computing system which can supply data on a subject for every subject in said subject space;

receiving at one or more computer processes in execution on one or more of said computers a subscription request from at least one consumer process, said subscription request specifying only the subject for which data is requested but not where data on said subject can be found in said distributed computing system and specifying a manner of returning data on the requested subject to said consumer process;

in one or more computer processes in execution on one or more of said computers, using the subject of said subscription request to automatically look up in said stored data encoding said subject space and the subjects therein, the identity and/or address in said distributed computing system of one or more source computer processes which can supply data on the subject specified in said subscription request, and automatically sending a subscription registration message to said source computer process specifying the subject for a subscription and specifying the manner of returning data on the specified subject to the consumer process which requested said data, said subscription registration message being sent to one or more subscription registration processes in execution on said one or more computers the function of which is to keep one or more subscription lists listing all active subscriptions on each subject;

receiving at said one or more source computer processes in execution on one or more of said computers one or more data messages from at least one publisher process which specify a subject and include data to be published on said subject but which do not specify where the data on said subject is to be sent within said distributed computing system other than by specifying the subject itself, and comparing the subject of each said data message to said one or more subscription lists kept by said one or more subscription registration processes and, if one or more active subscriptions exist for the subject of any particular data message, automatically sending all data messages on the subject and any subsequent data messages on the same subject to only those computers which have consumer processes in execution thereon having open subscriptions on the subject of said data messages, and for continuing to send each data message pertaining to a subject to only those computers having in execution thereon a consumer process having an active subscription for said subject until the subscription on said subject is canceled.

50. A distributed computing apparatus, comprising:

a plurality of 30 or more computers processing of which is controlled by a plurality of 30 or more programs or subroutines, said programs or subroutines in execution on one or more of said plurality of 30 or more computers, hereafter referred to as processes, said plurality of processes and said plurality of computers coupled by one or more data paths;

and wherein at least one of said computers has in execution thereon at least one of said processes which is a subscriber process which requests data on any subject in a hierarchically organized subject space having 30 or more subjects by issuing a subscription request requesting that a subscription be opened and naming the subject of the requested data and including data indicating how data on said subject is to be sent to said subscriber process, where no subscription request includes any data, other than the subject itself, indicating the identity or locations in said distributed computing environment of any publisher process which outputs data messages on the subject named in said subscription request;

and wherein at least one of said processes is a publisher process which publishes data messages on one or more subjects and which does not include any routine, computer code or subroutine the purpose of which is to receive any data, address or address related data the purpose of which is to control directly or indirectly where data being published by said publisher process is to be sent in said distributed computing environment or to send any data, address or address related data with said data messages being published, other than the subjects themselves of the data messages, which indicates or controls directly or indirectly where in said distributed computing apparatus to send any said data message;

one or more computers under control of one or more subject-based addressing programs or subroutines said one or more computers under control of said one or more subject-based addressing programs or subroutines being coupled to each said publisher process and each said subscriber process via said one or more data paths, said one or more subject-based addressing programs comprising one or more subscription handling routines for controlling execution on one or more of said computers so as to receive said subscription requests from said one or more subscriber processes and for keeping a list of active subscriptions of subjects for which there have been subscription requests made by one or more subscriber processes, and for automatically locating, for each active subscription, one or more computers coupled to or controlled by a process which can supply data on the subject of said subscription request, said one or more computers having their processing controlled by one or more programs which cause said one or more computers to supply data on the subject of each said subscription request, and said one or more computers under control of one or more subject-based addressing programs or subroutines for automatically establishing a data communication path for each said subscription request between the subscriber process which issued said subscription request and said one or more computers coupled to or controlled by said process that can supply data on the subject of said subscription request and automatically registering a subscription on the subject of said subscription request on said one or more computers coupled to or controlled by said process that can supply data on the subject so as to start a flow of data on said subject over said data communication path previously established, and said one or more subject-based addressing programs or subroutines for controlling said one or more computers so as to pass each data message received from said one or more computers coupled to or controlled by said process which can supply data on the subject of said subscription request only to computers under control of said one or more subscriber processes having an active subscription on the subject of each said data message.

51. The apparatus of claim 50 wherein said one or more computers controlled by said one or more subject-based addressing programs further comprise one or more computers controlled by one or more published message routing processes so as to receive data messages published by said one or more computers coupled to or controlled by said process which can supply data on the subject of each said subscription request, and, without receiving any data, command or request from any said publisher process controlling, assisting in controlling or indicating where each said data message is to be sent, for automatically and continuously sending each data message published on any said subject only to computers controlled by subscriber processes that have active subscriptions on the subject of said data message using the one or more data communication paths that have been opened for that subject and, wherein, for each said subscription request, said one or more computers controlled by one or more published message routing processes and said one or more subject-based addressing programs or subroutines automatically carry out one or more communication protocols and any necessary data format conversion operations that enable the computer controlled by a subscriber process which issued said subscription request on a subject to effectively communicate with the one or more computers coupled to or controlled by said process which can supply data on the subject of said subscription request.

52. A process for communicating data between software processes operating in one or more computers coupled by a data communication path, comprising:

storing data encoding a subject space and the subjects therein in a memory of one or more of said computers, and storing in said memory data mapping the identity and/or the address of one or more source processes for execution on one or more of said computers which can supply data on a subject for every subject in said subject space;

receiving a subscription request for information on a particular subject from a requesting software process and locating at least one suitable said source process for data on said subject by searching said data stored in said computer memory encoding said subject space using the subject of said subscription request as a search criteria; and

automatically satisfying all access requirements including invoking and carrying out all necessary communication protocols and data format and representation conversions needed to set up a communication channel through said data communication path between said source process and said requesting software process such that a subscription is set up whereby current data on the requested subject and subsequent data updates on the requested subject flows through said communication channel only to computers being controlled by the requesting software process(es) and are converted automatically to the data format and representation used by said requesting software process(es) until said subscription request is canceled, all said access requirements being satisfied, communication protocols invoked and data format conversions being carried out automatically without the aid of any data from or processing by said source process or requesting process such that said requesting software process need only name the subject of the desired data and said source process need only output data on the requested subject and name the subject thereof with the necessary processing needed to get that data to the requesting software process and the configuration and/or operation of the data communication path being transparent to said source process.

53. A process for communicating data between software processes controlling processing of one or more computers coupled by a data communication path, one or more of said software processes being a consumer process that needs data and one or more of said software processes being a publisher process which publishes data on a subject, said publisher process, said consumer process and said data communication path having access requirements, comprising:

storing data encoding a subject space and the subjects therein in a memory of one or more of said computers, and storing in said memory data mapping the identity and/or the address of one or more publisher processes for execution on one or more of said computers which can supply data on a subject for every subject in said subject space;

receiving a subscription request for information on a particular subject from one or more consumer software processes where no consumer process needs to output any data or address information which specifies where the desired data can be found other than the subject itself, and locating at least one suitable publisher process which can publish data on said subject by searching said data stored in said computer memory encoding said subject space using the subject of said subscription request as a search criteria; and

automatically satisfying all said access requirements including invoking and carrying out all necessary communication protocols needed to set up a communication channel through said data communication path between said publisher process and only said computers processing of which is controlled by consumer software processes having open subscriptions on the subject of said subscription request such that a subscription is set up whereby current data on the requested subject and subsequent data updates on the requested subject flow through said communication channel and are routed automatically to only computers processing of which is controlled by consumer software processes which requested data on the specified subject until said subscription request is canceled, all said access requirements being satisfied and communication protocols being invoked automatically without the aid of any data from or processing by said publisher process, other than by output of the subject itself, such that said publisher process need only output data on the requested subject and name the subject thereof with no need for said publisher process to have therein any software routine which knows the locations of consumer processes having open subscriptions to the subject or which is capable of finding the address of any said consumer process having an open subscription on the subject of the published data, with all the necessary processing needed to get the data published by said publisher process to all consumer software processes having open subscriptions on the subject of said published data by nonbroadcast communication processes being automatically performed by middleman software processes other than the publisher process or the consumer process or processes and wherein the configuration and operation and communication protocols of the data communication path and said middleman software processes are transparent to said publisher process and said consumer process or processes.

54. An apparatus comprising:

one or more computers having one or more software processes in execution thereon controlling operations of said one or more computers, at least one of said software processes being a consumer process that needs data on a subject and at least one of said software processes being a publisher process which publishes data on one or more subjects,

one or more data paths coupled to said one or more computers and capable of carrying data between said consumer and publisher processes in execution on said one or more computers;

and wherein said one or more computers have intermediary software program(s) in execution thereon for controlling one or more of said computers to implement decoupled, subject based addressing whereby a consumer process can obtain data pertaining to a subject simply by entering a subscription request by invoking a subscribe function of an application programmatic interface, hereafter referred to as an API, implemented by said intermediary software program(s), said subscription request only naming the subject of the desired data and identifying a method for getting data on the requested subject back to the consumer process, and said intermediary software program(s) for controlling one or more computers to take the subject of said subscription request and automatically map said subject to the identity and/or address of one or more publisher processes which is/are capable of supplying data on said subject and wherein said intermediary software program(s) control one or more computers to automatically set up a data communication path for each said subscription request between said one or more publisher processes which publish data on the subject of said subscription request and only those computers being controlled by consumer processes having an open subscription to the subject of said subscription request, and wherein said API implemented by said intermediary software program(s) provides a publish function which can be invoked by a data publisher process when data on a subject is to be published thereby allowing a publisher process to have published data distributed to all consumer processes having open subscriptions to the subject of said published data simply by invoking said publish function, publishing said data and naming the subject thereof, and, when said publish function is invoked, said intermediary software program(s) receives the published data and automatically distributes said data only to computers controlled by consumer processes that have active subscriptions to the subject of the published data.

55. An apparatus comprising:

one or more computers having one or more software processes in execution thereon controlling operations of said one or more computers, at least one of said software processes being a consumer process that needs data on a subject and at least one of said software processes being a publisher process which publishes data on one or more subjects;

one or more data paths coupled to said one or more computers and capable of carrying data between said consumer and publisher processes in execution on said one or more computers;

and wherein said one or more computers have one or more intermediary software means in execution thereon for controlling one or more of said computers to implement decoupled, subject based addressing, said intermediary software means including one or more means for controlling said one or more computers to provide an application programmatic interface, hereafter referred to as an API, to each said consumer process, whereby each said consumer process can obtain data pertaining to a subject simply by entering a subscription request in the form of invoking a subscribe function of said API implemented by said intermediary software means, said subscription request naming the subject, and wherein said intermediary software means includes one or more mapping means for controlling said one or more computers to automatically map the subject of said subscription request to the identity and/or address of one or more publisher processes which is/are capable of supplying data on said subject, and wherein said intermediary software means includes one or more means for controlling said one or more computers to automatically establish a data communication path between all consumer processes having open subscriptions on a subject and one or more publisher processes which can publish data on the subject, and wherein said intermediary software means includes one or more means for implementing a publisher side API to provide a facility such that a data publisher process can invoke a publish function when data on a subject is to be published, and wherein said intermediary software means is also for controlling one or more computers to receive the published data when said publish function of said publisher side API is invoked and distribute said data automatically to only computers controlled by consumer processes that have active subscriptions to the subject of the published data and without the need for said publisher process to include any data or software routines that contains or output the addresses of any consumer process or which is designed to designate to which consumer processes said data is to be distributed or which is designed to locate any consumer process which has an open subscription to data on the subject of said published data or any other subject.

56. An apparatus for facilitating communication of data in a distributed system between two or more computer programs in execution on the same or different computers coupled by a data exchange medium, comprising:

a network comprised of at least one data transfer path, said network coupling said one or more computers by one or more data transfer paths;

at least one computer execution of which is controlled by one or more application computer programs, said application computer program controlling said one or more computers by issuing a subscription request for data on a subject named in said subscription request;

at least one computer execution of which is controlled by one or more data publishing computer programs which may or may not be the same as said application computer program, said data publishing computer program controlling execution on at least one said computer so as to output data on at least one subject;

one or more computers controlled by one or more subject based addressing programs so as to logically decouple said one or more application computer programs from said one or more data publishing computer programs by providing an application programmatic interface to said one or more application computer programs such that said one or more application computer programs need not have any routines therein to locate or communicate with any other computer or computer program to obtain data on a subject other than to issue said subscription request through said application programmatic interface to said one or more computers controlled by said subject based addressing program and said one or more computers controlled by said subject based addressing program will automatically locate a computer controlled by a data publishing computer program which publishes data on said subject and will obtain data on said subject and pass said subject to said application computer program which issued said subscription request thereby insulating said application computer programs from obsolescence when changes or substitutions occur in the one or more data publishing computer programs which controls said one or more computers to publish data requested by said one or more application computer programs, said subject based addressing programs also for controlling said one or more computers such that data published by one or more computers controlled by one or more data publishing computer programs that is on a subject for which there is no active subscription is filtered out by the one or more computers executing said one or more data publishing computer programs such that said data is never transmitted on said network, said subject based addressing programs also for controlling said one or more computers such that data published by said one or more computers executing said one or more data publishing computer programs that is on one or more subjects for which there are active subscriptions is transmitted only to computers controlled by said one or more application computer programs that issued subscription requests on the subject of said data, said subject based addressing programs also for controlling said one or more computers such that an application programmatic interface is presented to one or more said data publishing programs such that said one or more computers executing said data publishing programs can transmit data published on a subject for which there is an active subscription only to those computers execution of which is controlled by one or more application computer programs which requested said data by outputting said data and the subject thereof through said application programmatic interface to said one or more computers controlled by said one or more subject based addressing computer programs such that said one or more data publishing need not include any routines or computer program instructions designed to locate or communicate with any computer controlled by one or more application computer programs other than to output data and the subject thereof through said application programmatic interface thereby insulating said data publishing computer programs from obsolescence when changes or substitutions occur in the one or more application computer programs which controls said one or more computers to request data published by said one or more data publishing computer programs.