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

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.

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.

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;
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• 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.

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.

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.

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.

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.

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.

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.

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.

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.

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.