US20020052932A1 - Collaborative object architecture - Google Patents

Collaborative object architecture Download PDF

Info

Publication number
US20020052932A1
US20020052932A1 US09/993,639 US99363901A US2002052932A1 US 20020052932 A1 US20020052932 A1 US 20020052932A1 US 99363901 A US99363901 A US 99363901A US 2002052932 A1 US2002052932 A1 US 2002052932A1
Authority
US
United States
Prior art keywords
message
pod
applet
messages
constituent parts
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US09/993,639
Inventor
Pavel Curtis
Micheal Dixon
David Nichols
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Microsoft Technology Licensing LLC
Placeware Inc
Original Assignee
Placeware Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Placeware Inc filed Critical Placeware Inc
Priority to US09/993,639 priority Critical patent/US20020052932A1/en
Publication of US20020052932A1 publication Critical patent/US20020052932A1/en
Assigned to MICROSOFT TECHNOLOGY LICENSING, LLC reassignment MICROSOFT TECHNOLOGY LICENSING, LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MICROSOFT CORPORATION
Abandoned legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/01Protocols
    • H04L67/10Protocols in which an application is distributed across nodes in the network
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/40Network security protocols
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/01Protocols
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/01Protocols
    • H04L67/131Protocols for games, networked simulations or virtual reality
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/30Definitions, standards or architectural aspects of layered protocol stacks
    • H04L69/32Architecture of open systems interconnection [OSI] 7-layer type protocol stacks, e.g. the interfaces between the data link level and the physical level
    • H04L69/322Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions
    • H04L69/329Intralayer communication protocols among peer entities or protocol data unit [PDU] definitions in the application layer [OSI layer 7]

Definitions

  • the present invention relates to multi-user computer applications. More specifically, the present invention relates to a collaborative object architecture for use with networked computers.
  • conferencing programs and gaming programs, each of which allow multiple computer users to interactively exchange information in real time.
  • a computer chat room can allow a number of distributed users to view conversational text as it is typed by any one of the individual users
  • conferencing application may allow geographically distributed users to collectively draft and edit a single text document
  • gaming programs can allow multiple users to compete or collaborate in a virtual gaming environment.
  • process refers to an active execution of a computation, and is also commonly referred to as a task, job, or thread.
  • Distributed programming is frequently based on the client-server paradigm, wherein a process executing on a client system communicates with a process executing on a server system.
  • a client process makes requests for access to, and information from, a server process.
  • a client process and server process can be executing on the same computer system or they can be executing on separate networked systems.
  • a server is accessible by a network, such as the Internet, a large number of client systems from around the world can make requests on a server system.
  • a collaborative object architecture is described.
  • a pod application runs on a server computer system.
  • Applets run on one or more client computer systems coupled to the server computer system via a network.
  • Each pod and a corresponding applet on each client computer system comprises a collaborative object.
  • pods have multiple constituent parts having corresponding constituent parts in each corresponding applet. Changes generated by a constituent part in an applet are processed locally and communicated to the pod. The applet continues normal operation without waiting for a response from the pod. When the pod receives the changes, the corresponding constituent part processes the changes and communicates the changes to the applets that have not processed the changes. In one embodiment, multiple changes are communicated in a single message packet.
  • FIG. 1 is one embodiment of a computer system.
  • FIG. 2 is one embodiment of a collaborative object architecture.
  • FIG. 3 is one embodiment of a conceptual diagram of lightweight asynchronous messaging.
  • FIG. 4 is one embodiment of a distributed database having collaborative objects.
  • FIG. 5 is one embodiment of two messages of a single string object that cross in a network.
  • FIG. 6 is one embodiment of a state space for an applet and a pod while processing messages.
  • FIG. 7 is one embodiment of a state space in which an applet and a pod diverge by more than one step.
  • FIG. 8 is one embodiment of a flow diagram for sending a message.
  • FIG. 9 is one embodiment of a flow diagram for receiving a message.
  • the present invention provides a collaborative object architecture with one or more of the following: 1) lightweight asynchronous messaging; 2) collaborative objects; 3) optimistic concurrency control; and 4) transparent object serialization.
  • Lightweight asynchronous messaging allows responsive interactivity and natural interactions with minimal network loads.
  • Collaborative objects allow ubiquitous sharing and provides each user with the same copy of a shared object.
  • Optimistic concurrency control allows full-duplex group editing and natural interactions.
  • Transparent object serialization provides real world persistence and support for asynchronous changes. Thus, combination of these features provides a persistent collaborative-object messaging architecture with several advantages over the prior art.
  • FIG. 1 is one embodiment of a computer system.
  • Computer system 100 includes bus 101 or other communication device for communicating information, and processor 102 coupled with bus 101 for processing information.
  • Computer system 100 may also include multiple processors (not shown in FIG. 1).
  • Computer system 100 further includes random access memory (RAM) or other dynamic storage device 104 (referred to as main memory), coupled to bus 101 for storing information and instructions to be executed by processor 102 .
  • Main memory 104 also can be used for storing temporary variables or other intermediate information during execution of instructions by processor 102 .
  • Computer system 100 also includes read only memory (ROM) and/or other static storage device 106 coupled to bus 101 for storing static information and instructions for processor 102 .
  • Data storage device 107 is coupled to bus 101 for storing information and instructions.
  • Data storage device 107 such as a magnetic disk or optical disc and its corresponding drive can be coupled to computer system 100 .
  • Computer system 100 can also be coupled via bus 101 to display device 121 , such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user.
  • display device 121 such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user.
  • Alphanumeric input device 122 is typically coupled to bus 101 for communicating information and command selections to processor 102 .
  • cursor control 123 is Another type of user input device, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 102 and for controlling cursor movement on display 121 .
  • FIG. 2 is one embodiment of a collaborative object architecture.
  • each data set (or object) within the architecture has two distinct parts: one part that runs on a single server computer system and one or more copies of the second part that run on separate client computer systems, each of which connect to the server computer system via a network.
  • the phrase “data set” refers to a broad category of objects including, but not limited to, applications, files, etc.
  • applets run in a Web browser, such as Internet Explorer® available from Microsoft Corporation of Redmond, Washington or Navigator® available from Netscape Communications, Inc. of Mountain View, Calif. Alternatively, the applet can run in a different web browser or as a standalone application. In one embodiment, applets are built of classes defined by the JavaTM Programming Language available from Sun Microsystems of Mountain View, Calif.; however, any programming language can be used.
  • applets are standalone applications (client applications) rather than applets running in a Web browser.
  • client applications are installed in a client computer system prior to communication with a server.
  • a server application When a server application is running on a server computer system, the server accepts connections from clients and activates or deactivates server-side applications in response to the connections.
  • the server half of an application is referred to as a “pod.”
  • the server also maintains the persistent state of the pods.
  • a server provides an environment in which pods can run and receive connections from corresponding applets.
  • the server responds to TCP or HTTP connections made by client-side messaging substrate(s) and generates a sub-connection to an appropriate pod. It is important to note that any type of communication protocol that provides reliable, ordered communications can be used to implement the present invention.
  • Each collaborative object includes multiple constituent parts including a pod and one or more applets distributed across multiple computer systems. Applets and pods can be further subdivided into constituent sub-parts, which interact to provide collaborative sub-objects. Sub-parts can be further subdivided into multiple levels of sub-parts each of which interact with corresponding sub-parts to provide multiple levels of collaborative sub-objects. The relationship of constituent parts across multiple computer systems and the hierarchical relationship of sub-parts is described in greater detail below.
  • Network 200 provides an interconnection between multiple computer systems that operate as client computer systems and/or server computer systems.
  • Network 200 can be any type of computer network.
  • network 200 is the Internet.
  • network 200 can be local-area network (LAN), a wide-area network (WAN), etc.
  • FIG. 2 describes a single server communicating with to a single web browser via network 200 for simplicity. Any number of web browsers and any number of servers can be interconnected via network 200 and additional networks (not shown in FIG. 2); however, collaborative objects operate between a single server and multiple clients.
  • the network connection provides an applet with a bi-directional communication channel with the corresponding pod.
  • the communication takes the form of asynchronous remote procedure calls (RPCs) made by each side to the other.
  • RPCs remote procedure calls
  • Web browser 220 runs on a client computer system (not shown in FIG. 2) that provides computing resources for web browser 220 .
  • server application 240 runs on a server computer system (not shown in FIG. 2) that provides computing resources for server application 240 .
  • the particular environment in which applets and pods run may be varied and is not central to the present invention.
  • Web browser 220 runs one or more applets, such as applet 222 and applet 224 .
  • each applet can be further subdivided into multiple constituent parts, such as constituent parts 212 , 214 , 216 , 232 and 234 .
  • Constituent parts can be, for example, a shared string, a shared integer, etc.
  • Server 240 runs one or more pods, such as pods 250 and 260 .
  • each pod can be further subdivided into multiple constituent parts that correspond to respective constituent parts of applets running in web browser 220 or other web browsers (not shown in FIG. 2).
  • pod 250 corresponds to applet 210 and the three constituent parts of pod 250 (e.g., 252 , 254 and 256 ) correspond to the three constituent parts (e.g., 212 , 214 and 216 ) of applet 210 .
  • the two constituent parts of pod 260 e.g., 262 and 264
  • Communication between applets and corresponding pods occur over network 200 .
  • the network connection provides applets with a bidirectional communication channel with the corresponding pod.
  • the communication takes the form of asynchronous remote procedure calls (RPCs) made by each side to the other.
  • RPCs remote procedure calls
  • pods and applets communicate via a messaging substrate.
  • the messaging substrate is an optimized facility designed specifically to support interactive distributed applications running on any network.
  • the messaging substrate is designed for performance using high-latency networks by using small messages to reduce bandwidth requirements.
  • the first source of response latency is caused by sequential processing of events by a pod. Sequential processing refers to ordering of events that occur simultaneously or are received simultaneously by the pod.
  • the second source of response latency is high-latency communications paths. For example, low-bandwidth connections, busy networks, and high-latency links introduce delays to responses from other devices.
  • asynchronous lightweight messaging allows applets to continue operation without waiting for a response from the corresponding pod.
  • applets are not left idle waiting for pod response.
  • pods continue local operations without waiting for the applet to respond.
  • both the pod and the applet can continue operations without waiting for a response from the other device, thereby improving interactivity of distributed applications.
  • the underlying transport protocol must be reliable and provide ordered delivery.
  • messages sent by an applet are received by a corresponding pod in the same order in which the messages were sent.
  • TCP is used for messaging purposes; however, any protocol that provides reliable, ordered delivery of messages can be used.
  • FIG. 3 is one embodiment of a conceptual diagram of lightweight asynchronous messaging.
  • Network 300 provides interconnection between server 320 , web browser 340 and web browser 360 .
  • Pods 322 , 324 and 326 run in server 320 .
  • Applets 342 and 344 run in web browser 340 .
  • applets 362 and 364 run in web browser 360 .
  • Message bursts generated by the web browsers and the server can include multiple messages.
  • message burst 350 includes two messages generated by an applet running in web browser 360 .
  • the term “message bursts” refers to any grouping of messages sent across a network, regardless of network protocol and packet format.
  • Message burst 330 includes three messages generated by an applet running in web browser 340 .
  • Pods communicate messages in a similar manner.
  • message burst 310 includes four messages from a pod running in server 320 .
  • compact representations are used to reduce the amount of data included in each message. For example, if an integer is less than 256 , the number is sent as one byte of data. Larger integers are sent as larger blocks of data. Similar compact representations are used for other data. In this manner messages are optimized to reduce the non-essential data included in each message. Lightweight messaging allows small change information to be sent frequently. This makes the collaborative object appear more “live” because the user receives better feedback. Lightweight messaging is also beneficial for use with high-latency networks such as the Internet for the same reason.
  • multiple messages can be bundled into a single message burst.
  • multiple messages can be included in a single TCP packet or HTTP request.
  • the asynchronous nature of messaging provided by the present invention allows message bundling because a sending object is not required to wait for a response from the receiving object. In a call and return architecture only a single message can be sent because the sending object cannot proceed without a response from the receiving object.
  • a single TCP connection is shared between all applets running on a single browser and a corresponding server application running corresponding pods.
  • the constituent sub-parts of an applet communicate with the corresponding constituent sub-parts of a pod over the shared connection.
  • Collaborative objects refers to many constituent parts on many hosts that act as a single object. As discussed above, each object has a server side (pod) and one or more client sides (applets). Each pod and/or applet can be further sub-divided into constituent parts that communicate with corresponding constituent parts. In one embodiment, constituent parts are chosen from a library of constituent parts; however, custom constituent parts can be designed.
  • the library of constituent parts can provide lower-level functionality, such as constituent parts that manipulate strings, numerical values, etc.
  • Higher-level collaborative objects can be built from the lower-level collaborative objects included in the library.
  • a database query higher-level collaborative object can include multiple string objects and multiple integer objects.
  • the database query object can then be shared by multiple applets and a corresponding pod.
  • Collaborative objects also provide an applet with more local intelligence than prior art shared objects operating with a call and return protocol.
  • An applet can provide local processing of shared objects without the need of communicating with the pod. For example, an applet can search a local copy of a collaborative string object to determine whether a particular sub-string exists without communicating a search request to the pod. Thus, applet operations do not necessarily correspond with remote procedure calls.
  • FIG. 4 is one embodiment of a distributed database having collaborative objects.
  • the collaborative object is a database; however, collaborative objects can operate on any set of data, whether executable or not. Constituent parts of the collaborative object can be used, for example, to author queries, modify data, etc.
  • Server application 410 runs a pod that consists of pod core 412 , collaborative integer constituent part 414 and collaborative string constituent part 416 .
  • Pod core 412 has access to data 420 that is not a part of server application 410 .
  • applets do not directly intercommunicate. Applets send messages to a corresponding pod and the pod manages coordination of collaborative objects.
  • Web browser 450 runs applet 470 that includes applet core 452 , collaborative integer constituent part 454 and collaborative string constituent part 456 .
  • Web browser 440 runs applet 460 that includes applet core 442 , collaborative integer constituent part 444 and collaborative string constituent part 446 .
  • the collaborative string constituent parts and the collaborative integer constituent parts are multiple instances of objects defined by the object library.
  • pod core 412 , applet core 442 and applet core 452 provide code sequences to manage communications between the pod/applet over shared TCP connections.
  • the core components include the messaging substrate described above.
  • the constituent parts that are included in pods and applets communicate with corresponding constituent parts in the manner described above in more general terms with respect to applets and pods.
  • Collaborative string constituent parts 416 , 446 and 456 are corresponding constituent parts that provide a collaborative string object used to define a query into the database to retrieve data from data 420 .
  • a user of web browser 450 writes a query using a keyboard or other input device (not shown in FIG. 4)
  • the query is input to a user interface (not shown in FIG. 4) of web browser 450 .
  • the user interface communicates the query to collaborative string constituent part 456 that modifies a local copy of the string.
  • Collaborative string constituent part 456 then communicates the query to collaborative string constituent part 416 .
  • the query is communicated as part of a message burst between applet 470 and pod 480 .
  • Collaborative string constituent part 416 updates the server-side local version of the string in response to the message received from applet 470 . Coordination of messages between multiple applets and a corresponding pod is described in greater detail below. Collaborative string constituent part 416 then communicates the query to collaborative string constituent part 446 that is part of applet 460 , as well as to any other corresponding applets (not shown in FIG. 4). Collaborative string constituent part 446 changes the local copy of the string and communicates the string to the user interface (not shown in FIG. 4) of Web browser 440 .
  • communications occur directly between the constituent parts of a collaborative object.
  • the corresponding pod and applets do not manage communications or updates to data controlled by the constituent parts.
  • constituent parts of applets and pods as well as constituent sub-parts along with corresponding parts or sub-parts operate as collaborative objects or collaborative sub-objects, without management by the higher-level applets and pod.
  • the present invention allows use of asynchronous communications between parts to provide a more responsive architecture than prior art shared object architectures.
  • the user of web browser 440 can also make modifications to the string to change the database query. Any changes to the string are processed in the same manner as the original query described above.
  • other constituent parts can be used to provide different data in a similar manner.
  • collaborative integer constituent parts 414 , 444 and 454 can be used for communicating other data between within collaborative objects, for example, updating data 420 .
  • Constituent parts can be further subdivided into multiple constituent sub-parts or larger collaborative objects can be built from constituent parts (not shown in FIG. 4).
  • constituent parts for example, collaborative string constituent part 416 and collaborative integer constituent part 414 together can define a database query pod constituent part.
  • the corresponding applet constituent parts define respective database query applet constituent parts. Together the constituent parts provide a database query collaborative object.
  • Constituent sub-parts communicate directly with corresponding constituent sub-parts in the same manner as the constituent parts described above.
  • changes to an object are made without update and coordination with other objects of the same applet.
  • changes to collaborative integer constituent part 444 can be communicated after changes to collaborative string constituent part 446 are communicated, but before the pod has completed processing of the changes to collaborative string constituent part 446 . This allows a user to continue to use an applet without having to wait for processing of previous changes to be completed.
  • serialization refers to the process of transforming a complex data set (e.g., a database) into a linear data set that can be stored on data storage device (e.g., a hard disk).
  • object serialization is used to provide persistence for collaborative objects.
  • pods reside on a hard disk or other storage device in the server computer system.
  • the server computer system loads the pod into main memory and restores the state of the pod as of the last time the pod was active.
  • the server then delivers the incoming messages to the active pod.
  • the server when the pod's messages have been processed and the pod is no longer active, the server saves the state of the pod, moves the pod to hard disk or other storage device and clears the pod from main memory.
  • a server computer system can support a large number of pods without using correspondingly large amounts of memory.
  • pods consume resources of the server computer system only when active and being used by clients.
  • Periodic serialization can initiated to maintain persistence for collaborative objects.
  • servers serialize objects that have been active for a preselected period of time without serialization.
  • Periodic serialization allows the state of the pod to be saved when the pod is active so that the state can be retrieved should an event occur that would cause the pod to lose data, such as the server computer system crashing.
  • periodic serialization should occur between messages.
  • concurrency control requires communication with other systems (e.g., a server) before changing locally (e.g., the client).
  • Optimistic concurrency control does not require communications before making a local change.
  • Optimistic algorithms are well-suited for high-latency comminations because the result of a user's action can be displayed before an associated message makes a round-trip between the applet and the server.
  • applets communicate with other applets to provide concurrency control.
  • applets communicate with pods and the pods provide concurrency control.
  • distributed optimistic concurrency control can become complex very rapidly as applets are added to the architecture. The increased complexity increases network resources required to provide concurrency control between applets.
  • One embodiment of optimistic concurrency control is described in detail in a paper entitled “HIGH-LATENCY, LOW-BANDWIDTH WINDOWING IN THE JUPITER COLLABORATION SYSTEM” published in the Proceedings of the Eighth Annual Symposium on User Interface Software and Technology (UIST), Nov. 15-17, 1995.
  • the present invention provides a centralized architecture with optimistic concurrency control.
  • optimistic concurrency control is provided only for individual applet-pod links. In this manner, each applet appears to operate synchronously with respect to the pod.
  • the pod can use a change propagation algorithm to update all applets and thereby provide concurrency control between applets. In one embodiment, if either the applet or the pod initiates a change to data, the change is applied locally and a message describing the change is sent to the other party.
  • optimistic concurrency control allows applets to change data without having to wait for pod interaction. If either the applet or the pod initiates a change, the change is immediately applied locally and a message is sent to the corresponding party.
  • each receiver modifies the incoming message so that the message makes sense relative to the receiving object's current state. Modifying conflicting messages is described in greater detail below.
  • Concurrency control is not applied directly between applets, instead concurrency control is applied between a pod and a single applet as messages are received from the individual applets. Changes are then broadcast to the other corresponding applets.
  • concurrency control is applied between a pod and a single applet as messages are received from the individual applets. Changes are then broadcast to the other corresponding applets.
  • a two-way optimistic concurrency control algorithm can be applied to an n-way collaborative object architecture, which is much simpler than implementing the n-way optimistic concurrency control.
  • FIG. 5 is one embodiment of two messages of a single string object that cross in a network.
  • the example of FIG. 5 is an update conflict that results in an incorrect update.
  • Concurrency control of the present invention allows collaborative objects to recognize the conflict and modify messages when necessary to avoid such conflicts.
  • DEL — 4 message 554 from applet 550 Prior to pod 510 processing DEL — 4 message 554 from applet 550 , a user of pod 510 deletes “B” and pod 510 generates DEL — 2 message 514 in response to delete the second letter in string 512 , which results in string 516 (“ACDE”). DEL — 2 message 514 is then communicated to applet 550 via network 500 . Prior to processing the delete messages, string 556 in applet 550 includes “ABCE” and string 516 in pod 510 includes “ACDE”.
  • Concurrency control modifies DEL — 4 message 554 from applet 550 to a DEL — 3 message to delete “D” from string 516 instead of deleting “E”.
  • the architecture of the present invention includes concurrency control to handle update conflicts so that pods and corresponding applets have the same data when all appropriate message have been processed.
  • the XFORM function is intended to describe a broad category of functions that have the properties that are described below. In the following description
  • a and P refer to the original applet and pod messages, respectively.
  • Messages A′ and P′ have the property that if the applet applies A followed by P′, and the pod applies P followed by A′, the applet and the pod will be in the same state.
  • FIG. 6 is one embodiment of a state space for an applet and a pod while processing messages. Each node is labeled with the number of applet and pod messages processed when in that state. Solid lines indicate the applet path and dotted lines indicate the pod path. For example, if the applet is in state (2,3), the applet has processed two of its own messages and three messages from the corresponding pod. In the example of FIG. 6, a conflict occurs starting from state (1,1).
  • the applet and pod move through the state space of FIG. 6. If the applet and pod process messages in the same order, no conflicts occur and the applet and pod take the same path (e.g., (0,0) to (1,0) to (1,1)). In the example, of FIG. 6, the applet and pod process different messages while in state (1,1). As a result, the applet moves to state (2,1) and the pod moves to state (1,2). To resolve the conflict of being in different states, both the applet and the pod process the message from the other party with the appropriate XFORM function.
  • Processing messages with the XFORM function moves both the applet and the pod to state (2,2).
  • the applet and pod both process a message from the pod to move to state (2,3).
  • the XFORM function(s) are used to reconcile the messages processed so that the applet and the pod move to the same state.
  • the messaging protocol of the present invention labels each message with the state of the sender just prior to when the message was generated. These labels are used to detect conflicts and the XFORM function(s) are used to resolve the conflicts.
  • the messaging protocol guarantees that when an applet and pod reach the same state, all objects will have identical values.
  • the XFORM function takes a pair of applet and pod messages that were generated from the same starting state and returns transformed messages that allow the applet and the pod to reach the same final state.
  • the XFORM function can be used directly.
  • the applet and pod diverge by more than one state reconciliation is more complex and the XFORM function cannot be used directly.
  • FIG. 7 is one embodiment of a state space in which an applet and a pod diverge by more than one state.
  • the applet has executed A to move to state (1,0) then receives a conflicting P 1 message from the pod.
  • the applet uses the XFORM function to generate P 1 ′ to get to state (1,1).
  • the pod then generates P 2 from state (0,1), which indicates that the pod has not yet processed A.
  • the applet cannot use XFORM(A, P 2 ) because A and P 2 were not generated from the same starting state. For example using the XFORM function described above, if A is DEL — 4, P 1 is DEL — 1, and P 2 is DEL — 3, then the correct transform for P 2 is NO_OP; however XFORM(A, P 2 ) is DEL — 3.
  • the applet executes P 2 ′ to get to state (1,2). If the pod has processed the applet's message, the pod will be in state (1,2) also. If not, the next message will originate from (0,3), not shown in FIG. 7. For this reason, the applet stores A′′. This process continues until the applet and the pod are in the same state.
  • FIG. 8 is one embodiment of a flow diagram for sending a message.
  • the message is described in terms of being sent from an applet to a pod; however, messages sent from the pod to the applet are processed in the same manner.
  • the example of FIG. 8 assumes that the pod was last known in state (x, y) and has sent k messages, leaving the pod in state (x+k, y). These messages are kept in the outgoing queue.
  • MyMsgs refers to the number of messages processed by the generating object and OtherMsgs refers to the number of messages received and processed.
  • MyMsgs is x+k and OtherMsgs is y.
  • step 810 the operation is performed locally by the applet to move the applet to state (x+k, y+1).
  • the operation along with MyMsgs and OtherMsgs is sent to the pod.
  • step 830 the message sent to the pod is added to the outgoing message queue of the applet.
  • step 840 MyMsgs is incremented.
  • FIG. 9 is one embodiment of a flow diagram for receiving a message.
  • the example of FIG. 9 assumes the same starting state as the example of FIG. 8. Thus, the next message received must originate from one of the states between (x, y) and (x+k, y), inclusive. Assuming that the pod has processed an arbitrary number (i) of the k applet messages, the received message comes from state (x+i, y), which takes the pod to state (x+i, y+1).
  • step 910 a message is received.
  • Step 920 operates to remove the messages saved by the applet that take the applet from state (x, y) to (x+i, y) because those messages have been processed by the pod and are no longer necessary to implement hypothetical messages to reconcile divergent states.
  • step 930 the incoming message is transformed, if necessary, with respect to the saved messages as described above. In one embodiment, any messages transformed are saved as transformed messages.
  • step 930 The result of step 930 is a message that takes the applet from state (x+k, y) to (x+k, y+1).
  • step 940 the message resulting from step 930 is applied locally.
  • step 950 the operation is broadcast to corresponding active applets.
  • step 960 OtherMsgs is incremented.
  • the steps of FIG. 9 result in a saved sequence of messages that takes the applet from the last known pod state, (x+i, y+1) to the current state, (x+k, y+1).
  • messages are saved until the messages are acknowledged by the corresponding pod/applet in order to transform incoming messages properly. Acknowledgements can be piggy-backed on outgoing messages. If messages are one-sided, explicit acknowledgements can be generated.
  • a two-way concurrency control protocol can be used to provide n-way concurrency control.
  • Each applet individually communicates messages that are processed via a two-way protocol and the results are broadcast to other applets behaving in the same manner.
  • Optimistic concurrency control is well suited for use with lightweight asynchronous messaging because the applet/pod generating a message is free to continue operation without waiting for a response from the receiving pod/applet.
  • combination of optimistic concurrency control and lightweight asynchronous messaging provides objects with more natural, real-time response than would otherwise be possible.
  • Collaborative objects allow intelligence to be included in the applets so that operations can be performed without generating messages to a pod.
  • collaborative objects further improve the natural, real-time response that can be provided by objects as compared to the prior art.
  • Transparent object serialization provides persistence that allows a user to use an object without the need to manually save or otherwise be concerned with saving the state of an object.
  • Transparent object serialization can also reduce data losses should computer systems crash or otherwise lose state that has not been saved.

Abstract

A collaborative object architecture with one or more of the following technologies: 1) lightweight asynchronous messaging; 2) collaborative objects; 3) optimistic concurrency control; and 4) transparent object serialization. Lightweight asynchronous messaging allows highly responsive interactivity and natural interactions with minimal network loads. Collaborative objects allow ubiquitous sharing and provides each user with the same copy of the shared object. Optimistic concurrency control allows full-duplex group editing and natural interactions. Transparent object serialization provides real world persistence and support for asynchronous changes. Thus, combination of these technologies provides a collaborative object architecture with several advantages over the prior art.

Description

    FIELD OF THE INVENTION
  • The present invention relates to multi-user computer applications. More specifically, the present invention relates to a collaborative object architecture for use with networked computers. [0001]
  • BACKGROUND OF THE INVENTION
  • Advances in computer technology and the advent of the Internet have enabled geographically distributed computer users to execute computer programs from points around the world. Examples of distributed programs include computer chat rooms, conferencing programs and gaming programs, each of which allow multiple computer users to interactively exchange information in real time. For instance, a computer chat room can allow a number of distributed users to view conversational text as it is typed by any one of the individual users, a conferencing application may allow geographically distributed users to collectively draft and edit a single text document, and gaming programs can allow multiple users to compete or collaborate in a virtual gaming environment. [0002]
  • In order to perform distributed programming, it is necessary for two individual processes to maintain a bi-directional communication stream. The term “process” refers to an active execution of a computation, and is also commonly referred to as a task, job, or thread. Distributed programming is frequently based on the client-server paradigm, wherein a process executing on a client system communicates with a process executing on a server system. [0003]
  • In the client-server paradigm, a client process makes requests for access to, and information from, a server process. A client process and server process can be executing on the same computer system or they can be executing on separate networked systems. In an architecture where a server is accessible by a network, such as the Internet, a large number of client systems from around the world can make requests on a server system. [0004]
  • Distributed programs, however, typically are only distributed to the extent that multiple client systems have access to a program running on a server system that operates with request and wait remote procedure calls (RPCs). In these architectures, the client systems request a service from the server system and wait for a response before proceeding. Such architectures require substantial network resources to keep the client systems updated with changes to the program. As the number of users increases network and other computing resources required to provide satisfactory performance also increases. For these reasons, prior art distributed programs typically do not provide a scalable, near real time collaborative environment. [0005]
  • What is needed is an improved architecture that provides objects distributed among multiple computer systems that act as a single object. [0006]
  • SUMMARY OF THE INVENTION
  • A collaborative object architecture is described. A pod application runs on a server computer system. Applets run on one or more client computer systems coupled to the server computer system via a network. Each pod and a corresponding applet on each client computer system comprises a collaborative object. In one embodiment, pods have multiple constituent parts having corresponding constituent parts in each corresponding applet. Changes generated by a constituent part in an applet are processed locally and communicated to the pod. The applet continues normal operation without waiting for a response from the pod. When the pod receives the changes, the corresponding constituent part processes the changes and communicates the changes to the applets that have not processed the changes. In one embodiment, multiple changes are communicated in a single message packet. [0007]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements. [0008]
  • FIG. 1 is one embodiment of a computer system. [0009]
  • FIG. 2 is one embodiment of a collaborative object architecture. [0010]
  • FIG. 3 is one embodiment of a conceptual diagram of lightweight asynchronous messaging. [0011]
  • FIG. 4 is one embodiment of a distributed database having collaborative objects. [0012]
  • FIG. 5 is one embodiment of two messages of a single string object that cross in a network. [0013]
  • FIG. 6 is one embodiment of a state space for an applet and a pod while processing messages. [0014]
  • FIG. 7 is one embodiment of a state space in which an applet and a pod diverge by more than one step. [0015]
  • FIG. 8 is one embodiment of a flow diagram for sending a message. [0016]
  • FIG. 9 is one embodiment of a flow diagram for receiving a message. [0017]
  • DETAILED DESCRIPTION
  • A collaborative object architecture is described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the present invention. [0018]
  • Briefly, the present invention provides a collaborative object architecture with one or more of the following: 1) lightweight asynchronous messaging; 2) collaborative objects; 3) optimistic concurrency control; and 4) transparent object serialization. Lightweight asynchronous messaging allows responsive interactivity and natural interactions with minimal network loads. Collaborative objects allow ubiquitous sharing and provides each user with the same copy of a shared object. Optimistic concurrency control allows full-duplex group editing and natural interactions. Transparent object serialization provides real world persistence and support for asynchronous changes. Thus, combination of these features provides a persistent collaborative-object messaging architecture with several advantages over the prior art. [0019]
  • Overview of a Collaborative Object Architecture [0020]
  • FIG. 1 is one embodiment of a computer system. [0021] Computer system 100 includes bus 101 or other communication device for communicating information, and processor 102 coupled with bus 101 for processing information. Computer system 100 may also include multiple processors (not shown in FIG. 1). Computer system 100 further includes random access memory (RAM) or other dynamic storage device 104 (referred to as main memory), coupled to bus 101 for storing information and instructions to be executed by processor 102. Main memory 104 also can be used for storing temporary variables or other intermediate information during execution of instructions by processor 102. Computer system 100 also includes read only memory (ROM) and/or other static storage device 106 coupled to bus 101 for storing static information and instructions for processor 102. Data storage device 107 is coupled to bus 101 for storing information and instructions.
  • [0022] Data storage device 107 such as a magnetic disk or optical disc and its corresponding drive can be coupled to computer system 100. Computer system 100 can also be coupled via bus 101 to display device 121, such as a cathode ray tube (CRT) or liquid crystal display (LCD), for displaying information to a computer user. Alphanumeric input device 122, including alphanumeric and other keys, is typically coupled to bus 101 for communicating information and command selections to processor 102. Another type of user input device is cursor control 123, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor 102 and for controlling cursor movement on display 121.
  • FIG. 2 is one embodiment of a collaborative object architecture. In one embodiment, each data set (or object) within the architecture has two distinct parts: one part that runs on a single server computer system and one or more copies of the second part that run on separate client computer systems, each of which connect to the server computer system via a network. The phrase “data set” refers to a broad category of objects including, but not limited to, applications, files, etc. [0023]
  • For purposes of explanation herein, individual client parts of each application are called “applets.” In one embodiment, applets run in a Web browser, such as Internet Explorer® available from Microsoft Corporation of Redmond, Washington or Navigator® available from Netscape Communications, Inc. of Mountain View, Calif. Alternatively, the applet can run in a different web browser or as a standalone application. In one embodiment, applets are built of classes defined by the Java™ Programming Language available from Sun Microsystems of Mountain View, Calif.; however, any programming language can be used. [0024]
  • In alternative embodiments, applets are standalone applications (client applications) rather than applets running in a Web browser. In such embodiments, the client applications are installed in a client computer system prior to communication with a server. [0025]
  • When a server application is running on a server computer system, the server accepts connections from clients and activates or deactivates server-side applications in response to the connections. For explanation purposes herein, the server half of an application is referred to as a “pod.” The server also maintains the persistent state of the pods. [0026]
  • A server provides an environment in which pods can run and receive connections from corresponding applets. In one embodiment, the server responds to TCP or HTTP connections made by client-side messaging substrate(s) and generates a sub-connection to an appropriate pod. It is important to note that any type of communication protocol that provides reliable, ordered communications can be used to implement the present invention. [0027]
  • Each collaborative object includes multiple constituent parts including a pod and one or more applets distributed across multiple computer systems. Applets and pods can be further subdivided into constituent sub-parts, which interact to provide collaborative sub-objects. Sub-parts can be further subdivided into multiple levels of sub-parts each of which interact with corresponding sub-parts to provide multiple levels of collaborative sub-objects. The relationship of constituent parts across multiple computer systems and the hierarchical relationship of sub-parts is described in greater detail below. [0028]
  • [0029] Network 200 provides an interconnection between multiple computer systems that operate as client computer systems and/or server computer systems. Network 200 can be any type of computer network. In one embodiment, network 200 is the Internet. Alternatively, network 200 can be local-area network (LAN), a wide-area network (WAN), etc.
  • FIG. 2 describes a single server communicating with to a single web browser via [0030] network 200 for simplicity. Any number of web browsers and any number of servers can be interconnected via network 200 and additional networks (not shown in FIG. 2); however, collaborative objects operate between a single server and multiple clients. In one embodiment, the network connection provides an applet with a bi-directional communication channel with the corresponding pod. In one embodiment, the communication takes the form of asynchronous remote procedure calls (RPCs) made by each side to the other.
  • [0031] Web browser 220 runs on a client computer system (not shown in FIG. 2) that provides computing resources for web browser 220. Similarly, server application 240 runs on a server computer system (not shown in FIG. 2) that provides computing resources for server application 240. The particular environment in which applets and pods run may be varied and is not central to the present invention.
  • [0032] Web browser 220 runs one or more applets, such as applet 222 and applet 224. In one embodiment, each applet can be further subdivided into multiple constituent parts, such as constituent parts 212, 214, 216, 232 and 234. Constituent parts can be, for example, a shared string, a shared integer, etc.
  • [0033] Server 240 runs one or more pods, such as pods 250 and 260. In one embodiment, each pod can be further subdivided into multiple constituent parts that correspond to respective constituent parts of applets running in web browser 220 or other web browsers (not shown in FIG. 2). For example, pod 250 corresponds to applet 210 and the three constituent parts of pod 250 (e.g., 252, 254 and 256) correspond to the three constituent parts (e.g., 212, 214 and 216) of applet 210. Similarly, the two constituent parts of pod 260 (e.g., 262 and 264) correspond to the two constituent parts of applet 230 (e.g., 232 and 234).
  • Communication between applets and corresponding pods occur over [0034] network 200. The network connection provides applets with a bidirectional communication channel with the corresponding pod. In one embodiment, the communication takes the form of asynchronous remote procedure calls (RPCs) made by each side to the other. Asynchronous communication is described in greater detail below.
  • Lightweight Asynchronous Messaging [0035]
  • In one embodiment, pods and applets communicate via a messaging substrate. [0036]
  • The messaging substrate is an optimized facility designed specifically to support interactive distributed applications running on any network. The messaging substrate is designed for performance using high-latency networks by using small messages to reduce bandwidth requirements. [0037]
  • Network interactions are generally subject to two sources of response latency. [0038]
  • The first source of response latency is caused by sequential processing of events by a pod. Sequential processing refers to ordering of events that occur simultaneously or are received simultaneously by the pod. The second source of response latency is high-latency communications paths. For example, low-bandwidth connections, busy networks, and high-latency links introduce delays to responses from other devices. [0039]
  • In one embodiment, asynchronous lightweight messaging allows applets to continue operation without waiting for a response from the corresponding pod. Thus, unlike rigid “call and return” messaging, applets are not left idle waiting for pod response. Similarly, pods continue local operations without waiting for the applet to respond. Thus, both the pod and the applet can continue operations without waiting for a response from the other device, thereby improving interactivity of distributed applications. [0040]
  • In order to properly implement asynchronous lightweight messaging, the underlying transport protocol must be reliable and provide ordered delivery. In other words, messages sent by an applet are received by a corresponding pod in the same order in which the messages were sent. In one embodiment, TCP is used for messaging purposes; however, any protocol that provides reliable, ordered delivery of messages can be used. [0041]
  • FIG. 3 is one embodiment of a conceptual diagram of lightweight asynchronous messaging. [0042] Network 300 provides interconnection between server 320, web browser 340 and web browser 360. Pods 322, 324 and 326 run in server 320. Applets 342 and 344 run in web browser 340. Similarly, applets 362 and 364 run in web browser 360.
  • Message bursts generated by the web browsers and the server can include multiple messages. For example, message burst [0043] 350 includes two messages generated by an applet running in web browser 360. The term “message bursts” refers to any grouping of messages sent across a network, regardless of network protocol and packet format. Message burst 330 includes three messages generated by an applet running in web browser 340. Pods communicate messages in a similar manner. For example, message burst 310 includes four messages from a pod running in server 320.
  • In one embodiment, compact representations are used to reduce the amount of data included in each message. For example, if an integer is less than [0044] 256, the number is sent as one byte of data. Larger integers are sent as larger blocks of data. Similar compact representations are used for other data. In this manner messages are optimized to reduce the non-essential data included in each message. Lightweight messaging allows small change information to be sent frequently. This makes the collaborative object appear more “live” because the user receives better feedback. Lightweight messaging is also beneficial for use with high-latency networks such as the Internet for the same reason.
  • As described above, multiple messages can be bundled into a single message burst. For example, multiple messages can be included in a single TCP packet or HTTP request. The asynchronous nature of messaging provided by the present invention allows message bundling because a sending object is not required to wait for a response from the receiving object. In a call and return architecture only a single message can be sent because the sending object cannot proceed without a response from the receiving object. [0045]
  • In one embodiment, a single TCP connection is shared between all applets running on a single browser and a corresponding server application running corresponding pods. The constituent sub-parts of an applet communicate with the corresponding constituent sub-parts of a pod over the shared connection. [0046]
  • Collaborative Objects [0047]
  • Collaborative objects refers to many constituent parts on many hosts that act as a single object. As discussed above, each object has a server side (pod) and one or more client sides (applets). Each pod and/or applet can be further sub-divided into constituent parts that communicate with corresponding constituent parts. In one embodiment, constituent parts are chosen from a library of constituent parts; however, custom constituent parts can be designed. [0048]
  • The library of constituent parts can provide lower-level functionality, such as constituent parts that manipulate strings, numerical values, etc. Higher-level collaborative objects can be built from the lower-level collaborative objects included in the library. For example, a database query higher-level collaborative object can include multiple string objects and multiple integer objects. The database query object can then be shared by multiple applets and a corresponding pod. [0049]
  • Collaborative objects also provide an applet with more local intelligence than prior art shared objects operating with a call and return protocol. An applet can provide local processing of shared objects without the need of communicating with the pod. For example, an applet can search a local copy of a collaborative string object to determine whether a particular sub-string exists without communicating a search request to the pod. Thus, applet operations do not necessarily correspond with remote procedure calls. [0050]
  • FIG. 4 is one embodiment of a distributed database having collaborative objects. In the example of FIG. 4, the collaborative object is a database; however, collaborative objects can operate on any set of data, whether executable or not. Constituent parts of the collaborative object can be used, for example, to author queries, modify data, etc. [0051]
  • [0052] Server application 410 runs a pod that consists of pod core 412, collaborative integer constituent part 414 and collaborative string constituent part 416. Pod core 412 has access to data 420 that is not a part of server application 410. As described in greater detail below, applets do not directly intercommunicate. Applets send messages to a corresponding pod and the pod manages coordination of collaborative objects.
  • [0053] Web browser 450 runs applet 470 that includes applet core 452, collaborative integer constituent part 454 and collaborative string constituent part 456. Similarly, Web browser 440 runs applet 460 that includes applet core 442, collaborative integer constituent part 444 and collaborative string constituent part 446. In one embodiment, the collaborative string constituent parts and the collaborative integer constituent parts are multiple instances of objects defined by the object library.
  • In one embodiment, [0054] pod core 412, applet core 442 and applet core 452 provide code sequences to manage communications between the pod/applet over shared TCP connections. For purposes of explanation with respect to FIG. 4, the core components include the messaging substrate described above. In one embodiment, the constituent parts that are included in pods and applets communicate with corresponding constituent parts in the manner described above in more general terms with respect to applets and pods.
  • Collaborative string [0055] constituent parts 416, 446 and 456 are corresponding constituent parts that provide a collaborative string object used to define a query into the database to retrieve data from data 420. When a user of web browser 450 writes a query using a keyboard or other input device (not shown in FIG. 4), the query is input to a user interface (not shown in FIG. 4) of web browser 450. The user interface communicates the query to collaborative string constituent part 456 that modifies a local copy of the string. Collaborative string constituent part 456 then communicates the query to collaborative string constituent part 416. In one embodiment, the query is communicated as part of a message burst between applet 470 and pod 480.
  • Collaborative string [0056] constituent part 416 updates the server-side local version of the string in response to the message received from applet 470. Coordination of messages between multiple applets and a corresponding pod is described in greater detail below. Collaborative string constituent part 416 then communicates the query to collaborative string constituent part 446 that is part of applet 460, as well as to any other corresponding applets (not shown in FIG. 4). Collaborative string constituent part 446 changes the local copy of the string and communicates the string to the user interface (not shown in FIG. 4) of Web browser 440.
  • In one embodiment, communications occur directly between the constituent parts of a collaborative object. The corresponding pod and applets do not manage communications or updates to data controlled by the constituent parts. In this manner, constituent parts of applets and pods as well as constituent sub-parts along with corresponding parts or sub-parts operate as collaborative objects or collaborative sub-objects, without management by the higher-level applets and pod. By providing independent objects operating together to form a higher level applet or pod, the present invention allows use of asynchronous communications between parts to provide a more responsive architecture than prior art shared object architectures. [0057]
  • The user of [0058] web browser 440 can also make modifications to the string to change the database query. Any changes to the string are processed in the same manner as the original query described above. Of course, other constituent parts can be used to provide different data in a similar manner. For example, collaborative integer constituent parts 414, 444 and 454 can be used for communicating other data between within collaborative objects, for example, updating data 420.
  • Constituent parts can be further subdivided into multiple constituent sub-parts or larger collaborative objects can be built from constituent parts (not shown in FIG. 4). For example, collaborative string [0059] constituent part 416 and collaborative integer constituent part 414 together can define a database query pod constituent part. The corresponding applet constituent parts define respective database query applet constituent parts. Together the constituent parts provide a database query collaborative object. Constituent sub-parts communicate directly with corresponding constituent sub-parts in the same manner as the constituent parts described above.
  • Because objects and sub-objects communicate using lightweight asynchronous messaging, changes to an object are made without update and coordination with other objects of the same applet. For example, changes to collaborative integer [0060] constituent part 444 can be communicated after changes to collaborative string constituent part 446 are communicated, but before the pod has completed processing of the changes to collaborative string constituent part 446. This allows a user to continue to use an applet without having to wait for processing of previous changes to be completed.
  • Transparent Object Serialization [0061]
  • As used herein, “serialization” refers to the process of transforming a complex data set (e.g., a database) into a linear data set that can be stored on data storage device (e.g., a hard disk). In one embodiment, object serialization is used to provide persistence for collaborative objects. [0062]
  • According to one embodiment of the present invention, unless active, pods reside on a hard disk or other storage device in the server computer system. When a connection is received for an inactive pod stored on a hard disk, the server computer system loads the pod into main memory and restores the state of the pod as of the last time the pod was active. The server then delivers the incoming messages to the active pod. [0063]
  • In one embodiment, when the pod's messages have been processed and the pod is no longer active, the server saves the state of the pod, moves the pod to hard disk or other storage device and clears the pod from main memory. By having the pod in main memory only when connections are open to the pod, a server computer system can support a large number of pods without using correspondingly large amounts of memory. Thus, pods consume resources of the server computer system only when active and being used by clients. [0064]
  • Periodic serialization can initiated to maintain persistence for collaborative objects. In one embodiment, servers serialize objects that have been active for a preselected period of time without serialization. Periodic serialization allows the state of the pod to be saved when the pod is active so that the state can be retrieved should an event occur that would cause the pod to lose data, such as the server computer system crashing. In order to coordinate the state of the pod with the stored state, periodic serialization should occur between messages. [0065]
  • Optimistic Concurrency Control [0066]
  • In general, two types of concurrency control (e.g., pessimistic and optimistic) and two types of collaborative architectures (e.g., centralized and distributed) can be provided, which results in four choices for concurrency control. Pessimistic concurrency control requires communication with other systems (e.g., a server) before changing locally (e.g., the client). Optimistic concurrency control, on the other hand, does not require communications before making a local change. Optimistic algorithms are well-suited for high-latency comminations because the result of a user's action can be displayed before an associated message makes a round-trip between the applet and the server. [0067]
  • In distributed architectures, applets communicate with other applets to provide concurrency control. In centralized architectures, applets communicate with pods and the pods provide concurrency control. Because of the many possible messages required, distributed optimistic concurrency control can become complex very rapidly as applets are added to the architecture. The increased complexity increases network resources required to provide concurrency control between applets. One embodiment of optimistic concurrency control is described in detail in a paper entitled “HIGH-LATENCY, LOW-BANDWIDTH WINDOWING IN THE JUPITER COLLABORATION SYSTEM” published in the Proceedings of the Eighth Annual Symposium on User Interface Software and Technology (UIST), Nov. 15-17, 1995. As described in greater detail below, the present invention provides a centralized architecture with optimistic concurrency control. [0068]
  • In one embodiment of the present invention, optimistic concurrency control is provided only for individual applet-pod links. In this manner, each applet appears to operate synchronously with respect to the pod. The pod can use a change propagation algorithm to update all applets and thereby provide concurrency control between applets. In one embodiment, if either the applet or the pod initiates a change to data, the change is applied locally and a message describing the change is sent to the other party. [0069]
  • As discussed earlier, optimistic concurrency control allows applets to change data without having to wait for pod interaction. If either the applet or the pod initiates a change, the change is immediately applied locally and a message is sent to the corresponding party. When messages cross in the network, each receiver modifies the incoming message so that the message makes sense relative to the receiving object's current state. Modifying conflicting messages is described in greater detail below. [0070]
  • Concurrency control is not applied directly between applets, instead concurrency control is applied between a pod and a single applet as messages are received from the individual applets. Changes are then broadcast to the other corresponding applets. In this manner, a two-way optimistic concurrency control algorithm can be applied to an n-way collaborative object architecture, which is much simpler than implementing the n-way optimistic concurrency control. [0071]
  • FIG. 5 is one embodiment of two messages of a single string object that cross in a network. The example of FIG. 5 is an update conflict that results in an incorrect update. Concurrency control of the present invention allows collaborative objects to recognize the conflict and modify messages when necessary to avoid such conflicts. [0072]
  • If the messages of FIG. 5 are not transformed on receipt, the final values in [0073] applet 550 and pod 510 are different. The original strings, string 552 in applet 550 and string 512 in pod 510 are the same (“ABCDE”). The user of applet 550 deletes “D” and applet 550 generates DEL 4 message 554 in response to delete the fourth letter in string 552, which results in string 556 (“ABCE”). DEL 4 message 554 is communicated to pod 510 via network 500.
  • Prior to [0074] pod 510 processing DEL 4 message 554 from applet 550, a user of pod 510 deletes “B” and pod 510 generates DEL 2 message 514 in response to delete the second letter in string 512, which results in string 516 (“ACDE”). DEL 2 message 514 is then communicated to applet 550 via network 500. Prior to processing the delete messages, string 556 in applet 550 includes “ABCE” and string 516 in pod 510 includes “ACDE”.
  • When [0075] pod 510 processes DEL 4 message 554, the fourth letter in the string (“E”) is deleted to result in string 520 (“ACD”). Similarly, when applet processes DEL 2 message 514, the second letter in the string (“B”) is deleted to result in string 560 including “ACE”. Thus, without concurrency control, the final string in applet 550 and pod 510 do not match.
  • Concurrency control according to the present invention modifies [0076] DEL 4 message 554 from applet 550 to a DEL3 message to delete “D” from string 516 instead of deleting “E”. As described below, the architecture of the present invention includes concurrency control to handle update conflicts so that pods and corresponding applets have the same data when all appropriate message have been processed.
  • A general tool for handling update conflicts is described as the XFORM function. The XFORM function is intended to describe a broad category of functions that have the properties that are described below. In the following description [0077]
  • XFORM(A, P)={A_40 , P′},
  • where A and P refer to the original applet and pod messages, respectively. Messages A′ and P′ have the property that if the applet applies A followed by P′, and the pod applies P followed by A′, the applet and the pod will be in the same state. [0078]
  • In the update conflict example of FIG. 5, the following transform is an example of the transform that can be applied. [0079] XFORM ( del x , del y ) = { del x - 1 , del y } if x > y ; { del x , del y - 1 } if x < y ; and { no - op , no - op } if x = y .
    Figure US20020052932A1-20020502-M00001
  • In other words, later indexes in a string are modified to account for earlier deletions. [0080]
  • FIG. 6 is one embodiment of a state space for an applet and a pod while processing messages. Each node is labeled with the number of applet and pod messages processed when in that state. Solid lines indicate the applet path and dotted lines indicate the pod path. For example, if the applet is in state (2,3), the applet has processed two of its own messages and three messages from the corresponding pod. In the example of FIG. 6, a conflict occurs starting from state (1,1). [0081]
  • As messages are processed, the applet and pod move through the state space of FIG. 6. If the applet and pod process messages in the same order, no conflicts occur and the applet and pod take the same path (e.g., (0,0) to (1,0) to (1,1)). In the example, of FIG. 6, the applet and pod process different messages while in state (1,1). As a result, the applet moves to state (2,1) and the pod moves to state (1,2). To resolve the conflict of being in different states, both the applet and the pod process the message from the other party with the appropriate XFORM function. [0082]
  • Processing messages with the XFORM function moves both the applet and the pod to state (2,2). The applet and pod both process a message from the pod to move to state (2,3). Thus, as the applet and pod states diverge, the XFORM function(s) are used to reconcile the messages processed so that the applet and the pod move to the same state. [0083]
  • The messaging protocol of the present invention labels each message with the state of the sender just prior to when the message was generated. These labels are used to detect conflicts and the XFORM function(s) are used to resolve the conflicts. The messaging protocol guarantees that when an applet and pod reach the same state, all objects will have identical values. [0084]
  • The XFORM function takes a pair of applet and pod messages that were generated from the same starting state and returns transformed messages that allow the applet and the pod to reach the same final state. When the applet and pod diverge by only a single state the XFORM function can be used directly. However, when the applet and pod diverge by more than one state, reconciliation is more complex and the XFORM function cannot be used directly. [0085]
  • FIG. 7 is one embodiment of a state space in which an applet and a pod diverge by more than one state. In the example of FIG. 7, the applet has executed A to move to state (1,0) then receives a conflicting P[0086] 1 message from the pod. The applet uses the XFORM function to generate P1′ to get to state (1,1).
  • The pod then generates P[0087] 2 from state (0,1), which indicates that the pod has not yet processed A. The applet cannot use XFORM(A, P2) because A and P2 were not generated from the same starting state. For example using the XFORM function described above, if A is DEL 4, P1 is DEL1, and P2 is DEL3, then the correct transform for P2 is NO_OP; however XFORM(A, P2) is DEL3.
  • In the example of FIG. 7, when the applet computes P[0088] 1′, it also computes and stores A′, both of which are returned by the XFORM function. A′ represents a hypothetical message that the applet would have generated to move from state (0,1) to (1,1).
  • When P[0089] 2 arrives, the applet uses A′ to compute XFORM(A′, P2)={A″, P2′}. The applet executes P2′ to get to state (1,2). If the pod has processed the applet's message, the pod will be in state (1,2) also. If not, the next message will originate from (0,3), not shown in FIG. 7. For this reason, the applet stores A″. This process continues until the applet and the pod are in the same state.
  • FIG. 8 is one embodiment of a flow diagram for sending a message. The message is described in terms of being sent from an applet to a pod; however, messages sent from the pod to the applet are processed in the same manner. For purposes of explanation, the example of FIG. 8 assumes that the pod was last known in state (x, y) and has sent k messages, leaving the pod in state (x+k, y). These messages are kept in the outgoing queue. In the flow diagrams of FIGS. 8 and 9, MyMsgs refers to the number of messages processed by the generating object and OtherMsgs refers to the number of messages received and processed. For the applet, MyMsgs is x+k and OtherMsgs is y. [0090]
  • In [0091] step 810 the operation is performed locally by the applet to move the applet to state (x+k, y+1). In step 820, the operation along with MyMsgs and OtherMsgs is sent to the pod. In step 830, the message sent to the pod is added to the outgoing message queue of the applet. In step 840, MyMsgs is incremented.
  • FIG. 9 is one embodiment of a flow diagram for receiving a message. The example of FIG. 9 assumes the same starting state as the example of FIG. 8. Thus, the next message received must originate from one of the states between (x, y) and (x+k, y), inclusive. Assuming that the pod has processed an arbitrary number (i) of the k applet messages, the received message comes from state (x+i, y), which takes the pod to state (x+i, y+1). [0092]
  • In step [0093] 910 a message is received. Step 920 operates to remove the messages saved by the applet that take the applet from state (x, y) to (x+i, y) because those messages have been processed by the pod and are no longer necessary to implement hypothetical messages to reconcile divergent states. In step 930, the incoming message is transformed, if necessary, with respect to the saved messages as described above. In one embodiment, any messages transformed are saved as transformed messages.
  • The result of [0094] step 930 is a message that takes the applet from state (x+k, y) to (x+k, y+1). In step 940 the message resulting from step 930 is applied locally. In step 950, the operation is broadcast to corresponding active applets. In step 960, OtherMsgs is incremented. The steps of FIG. 9 result in a saved sequence of messages that takes the applet from the last known pod state, (x+i, y+1) to the current state, (x+k, y+1).
  • In one embodiment, messages are saved until the messages are acknowledged by the corresponding pod/applet in order to transform incoming messages properly. Acknowledgements can be piggy-backed on outgoing messages. If messages are one-sided, explicit acknowledgements can be generated. [0095]
  • By applying concurrency control between an applet and a pod and having the pod broadcast incoming messages to other applets, a two-way concurrency control protocol can be used to provide n-way concurrency control. Each applet individually communicates messages that are processed via a two-way protocol and the results are broadcast to other applets behaving in the same manner. [0096]
  • Summary [0097]
  • Optimistic concurrency control is well suited for use with lightweight asynchronous messaging because the applet/pod generating a message is free to continue operation without waiting for a response from the receiving pod/applet. Thus, combination of optimistic concurrency control and lightweight asynchronous messaging provides objects with more natural, real-time response than would otherwise be possible. [0098]
  • Collaborative objects allow intelligence to be included in the applets so that operations can be performed without generating messages to a pod. Thus, collaborative objects further improve the natural, real-time response that can be provided by objects as compared to the prior art. Transparent object serialization provides persistence that allows a user to use an object without the need to manually save or otherwise be concerned with saving the state of an object. Transparent object serialization can also reduce data losses should computer systems crash or otherwise lose state that has not been saved. [0099]
  • In the foregoing specification, the present invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. [0100]

Claims (19)

What is claimed is:
1. A collaborative-object architecture comprising:
a first computer system running a pod having a first set of constituent parts; and
a second computer system coupled to the first computer system, the second computer system running an applet having a second set of constituent parts, the pod and the applet together comprising a collaborative object, wherein the first set of constituent parts correspond to the second set of constituent parts such that changes to one of the second set of constituent parts cause corresponding changes to a corresponding constituent part in the first set of constituent parts;
wherein the applet receives input and generates a message to the pod in response to the input, and further wherein the applet applies the input without waiting for a response from the pod.
2. The architecture of claim 1, wherein the applet generates a message packet to the pod comprising multiple messages, and further wherein the messages are optimized to reduce non-essential data included in each message.
3. The architecture of claim 1, wherein data controlled by the pod is serialized and stored on a data storage device if a message packet is not received by the pod for a preselected period of time.
4. The architecture of claim 1, wherein the pod receives message packets from the applet and communicates the packets to additional applets.
5. The architecture of claim 1, wherein the pod receives message packets from multiple applets, determines an order in which to process the received message packets and communicates a set of data resulting from the processing to the multiple applets such that the multiple applets receive the set of data from messages originating from the pod.
6. A method for a collaborative-object architecture comprising:
running a pod having a first set of constituent parts on a server computer system coupled to a first client computer system running a first applet having a second set of constituent parts and to a second client computer system running a second applet having a third set of constituent parts;
receiving a message from one of the second set of constituent parts indicating a change to data controlled by the constituent part;
processing the message by changing a corresponding constituent part in the first set of constituent parts based on the message, wherein the first applet continues normal execution prior to the processing of the message; and
sending an update to the second applet indicating the change corresponding to the message.
7. The method of claim 6, wherein the step of receiving a message comprises receiving a message packet having multiple messages indicating changes to data controlled by the constituent part.
8. The method of claim 6, wherein the update comprises multiple messages, and further wherein the messages are optimized to reduce non-essential data included in each message.
9. The method of claim 6, wherein the step of receiving a message further comprises:
receiving a message from multiple applets;
determining an order in which to process the multiple messages; and
transforming incoming messages, if necessary, based on a state of the sending applet.
10. A computer readable medium having stored thereon sequences of instructions which when executed cause a processor to:
run a pod having a first set of constituent parts on a server computer system, wherein the server computer system is coupled to a first client computer system running a first applet having a second set of constituent parts and to a second client computer system running a second applet having a third set of constituent parts;
receive a message from one of the second set of constituent parts indicating a change to data controlled by the constituent part;
process the message by changing a corresponding constituent part in the first set of constituent parts based on the message, wherein the first applet continues normal execution prior to the processing of the message; and
send an update to the second applet indicating the change corresponding to the message.
11. The computer readable medium of claim 10, wherein the sequences of instructions further comprise sequences of instruction that, when executed, cause the processor to receive a message packet having multiple messages indicating changes to data controlled by the constituent part.
12. The computer readable medium of claim 10, wherein the update comprises multiple messages, and further wherein the messages are optimized to reduce non-essential data included in each message.
13. The computer readable medium of claim 10, wherein the sequences of instruction that cause the processor to receive a message further comprise sequences of instructions that cause the processor to:
receive a message from multiple applets;
determine an order in which to process the multiple messages; and
transform incoming messages, if necessary, based on a state of the sending applet.
14. A method for a collaborative-object architecture comprising:
running an applet having a first set of constituent parts;
receiving an input that indicates a change to data controlled by one of the first set of constituent parts;
generating a message indicating the change to the data;
sending the message to a pod having a constituent part corresponding to the constituent part receiving the change; and
continuing running the applet without waiting for a response from the pod.
15. The method of claim 14, wherein generating a message comprises generating multiple messages, and further wherein the messages are optimized to reduce non-essential data included in each message.
16. The method of claim 14, further comprising:
receiving an update from the pod indicating changes to the data;
transforming the update, if necessary, based on the state of the pod when the update is generated; and
modifying the data based on the update.
17. A computer readable medium having stored thereon sequences of instructions that, when executed, cause a processor to:
run an applet having a first set of constituent parts;
receive an input that indicates a change to data controlled by one of the first set of constituent parts;
generate a message indicating the change to the data;
send the message to a pod having a constituent part corresponding to the constituent part receiving the change; and
continue running the applet without waiting for a response from the pod.
18. The computer readable medium of claim 17, wherein the sequences of instructions that cause the processor to generate a message further comprise sequences of instructions that cause the processor to generate multiple messages, wherein the messages are optimized to reduce non-essential data included in each message.
19. The computer readable medium of claim 17, further comprising sequences of instruction that, when executed, cause the processor to:
receive an update from the pod indicating changes to the data;
transform the update, if necessary, based on the state of the pod when the update is generated; and
modify the data based on the update.
US09/993,639 1998-06-11 2001-11-27 Collaborative object architecture Abandoned US20020052932A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US09/993,639 US20020052932A1 (en) 1998-06-11 2001-11-27 Collaborative object architecture

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/096,101 US6338086B1 (en) 1998-06-11 1998-06-11 Collaborative object architecture
US09/993,639 US20020052932A1 (en) 1998-06-11 2001-11-27 Collaborative object architecture

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US09/096,101 Continuation US6338086B1 (en) 1998-06-11 1998-06-11 Collaborative object architecture

Publications (1)

Publication Number Publication Date
US20020052932A1 true US20020052932A1 (en) 2002-05-02

Family

ID=22255320

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/096,101 Expired - Lifetime US6338086B1 (en) 1998-06-11 1998-06-11 Collaborative object architecture
US09/993,639 Abandoned US20020052932A1 (en) 1998-06-11 2001-11-27 Collaborative object architecture

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/096,101 Expired - Lifetime US6338086B1 (en) 1998-06-11 1998-06-11 Collaborative object architecture

Country Status (6)

Country Link
US (2) US6338086B1 (en)
EP (1) EP1110149A4 (en)
JP (1) JP2002517858A (en)
AU (1) AU4434999A (en)
CA (1) CA2334737A1 (en)
WO (1) WO1999064959A1 (en)

Cited By (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20020107994A1 (en) * 1999-12-09 2002-08-08 Rickards William S. Collaboration engine: adding collaboration functionality to computer software
US20030179951A1 (en) * 2002-03-25 2003-09-25 Christiansen Bernd O. Method and apparatus for fast block motion detection
EP1381186A1 (en) * 2002-07-12 2004-01-14 Microsoft Corporation Deployment of configuration information
US6691157B2 (en) 1995-11-13 2004-02-10 Citrix Systems, Inc. Method and apparatus for making a hypermedium interactive
FR2861933A1 (en) * 2003-10-30 2005-05-06 Denis Henri Angilella Virtual collaborative environmental system for remote user, has server program processing messages from client programs requesting modification of environment in their reception order and sending modifications in order of reception
US7163272B2 (en) 2004-06-10 2007-01-16 Lexmark International, Inc. Inkjet print head
US20080147834A1 (en) * 2006-12-19 2008-06-19 Quinn William M System and method for achieving highly scalable real-time collaboration applications using http
US20090077474A1 (en) * 2002-04-22 2009-03-19 Rosebud Lms, Inc. Method and Software for Enabling N-Way Collaborative Work Over a Network of Computers
US20090106347A1 (en) * 2007-10-17 2009-04-23 Citrix Systems, Inc. Methods and systems for providing access, from within a virtual world, to an external resource
US20090164500A1 (en) * 2007-12-20 2009-06-25 Ankur Mathur System for providing a configurable adaptor for mediating systems
US20090183087A1 (en) * 2008-01-10 2009-07-16 Binfire Corpoartion Method and Apparatus for Real Time Image Transfer Between Two or More Computers
US20090254569A1 (en) * 2008-04-04 2009-10-08 Landmark Graphics Corporation, A Halliburton Compa Systems and Methods for Real Time Data Management in a Collaborative Environment
US20100005111A1 (en) * 2008-04-04 2010-01-07 Landmark Graphics Corporation, A Halliburton Company Systems and Methods for Correlating Meta-Data Model Representations and Asset-Logic Model Representations
US20100049795A1 (en) * 2000-11-03 2010-02-25 Juniper Networks, Inc. Method and system for providing secure access to private networks
US7792971B2 (en) 2005-12-08 2010-09-07 International Business Machines Corporation Visual channel refresh rate control for composite services delivery
US7809838B2 (en) 2005-12-08 2010-10-05 International Business Machines Corporation Managing concurrent data updates in a composite services delivery system
US7827288B2 (en) 2005-12-08 2010-11-02 International Business Machines Corporation Model autocompletion for composite services synchronization
US7921158B2 (en) 2005-12-08 2011-04-05 International Business Machines Corporation Using a list management server for conferencing in an IMS environment
US7937370B2 (en) 2000-09-22 2011-05-03 Axeda Corporation Retrieving data from a server
US7966418B2 (en) 2003-02-21 2011-06-21 Axeda Corporation Establishing a virtual tunnel between two computer programs
US8005934B2 (en) 2005-12-08 2011-08-23 International Business Machines Corporation Channel presence in a composite services enablement environment
US8055758B2 (en) 2000-07-28 2011-11-08 Axeda Corporation Reporting the state of an apparatus to a remote computer
US8060886B2 (en) 2002-04-17 2011-11-15 Axeda Corporation XML scripting of SOAP commands
US8065397B2 (en) 2006-12-26 2011-11-22 Axeda Acquisition Corporation Managing configurations of distributed devices
US8108543B2 (en) 2000-09-22 2012-01-31 Axeda Corporation Retrieving data from a server
US8190679B1 (en) * 2004-05-27 2012-05-29 Adobe Systems, Incorporated Real-time meeting object extensibility
US8200828B2 (en) 2005-01-14 2012-06-12 Citrix Systems, Inc. Systems and methods for single stack shadowing
US8230096B2 (en) 2005-01-14 2012-07-24 Citrix Systems, Inc. Methods and systems for generating playback instructions for playback of a recorded computer session
US8259923B2 (en) 2007-02-28 2012-09-04 International Business Machines Corporation Implementing a contact center using open standards and non-proprietary components
US8296441B2 (en) 2005-01-14 2012-10-23 Citrix Systems, Inc. Methods and systems for joining a real-time session of presentation layer protocol data
US8370479B2 (en) 2006-10-03 2013-02-05 Axeda Acquisition Corporation System and method for dynamically grouping devices based on present device conditions
US8406119B2 (en) 2001-12-20 2013-03-26 Axeda Acquisition Corporation Adaptive device-initiated polling
US8422851B2 (en) 2005-01-14 2013-04-16 Citrix Systems, Inc. System and methods for automatic time-warped playback in rendering a recorded computer session
US8594305B2 (en) 2006-12-22 2013-11-26 International Business Machines Corporation Enhancing contact centers with dialog contracts
US8615159B2 (en) 2011-09-20 2013-12-24 Citrix Systems, Inc. Methods and systems for cataloging text in a recorded session
US8935316B2 (en) 2005-01-14 2015-01-13 Citrix Systems, Inc. Methods and systems for in-session playback on a local machine of remotely-stored and real time presentation layer protocol data
US9055150B2 (en) 2007-02-28 2015-06-09 International Business Machines Corporation Skills based routing in a standards based contact center using a presence server and expertise specific watchers
US9247056B2 (en) 2007-02-28 2016-01-26 International Business Machines Corporation Identifying contact center agents based upon biometric characteristics of an agent's speech

Families Citing this family (74)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7555529B2 (en) * 1995-11-13 2009-06-30 Citrix Systems, Inc. Interacting with software applications displayed in a web page
US6289461B1 (en) * 1998-06-09 2001-09-11 Placeware, Inc. Bi-directional process-to-process byte stream protocol
US6338086B1 (en) * 1998-06-11 2002-01-08 Placeware, Inc. Collaborative object architecture
US7043529B1 (en) * 1999-04-23 2006-05-09 The United States Of America As Represented By The Secretary Of The Navy Collaborative development network for widely dispersed users and methods therefor
US6928469B1 (en) * 1998-12-29 2005-08-09 Citrix Systems, Inc. Apparatus and method for determining a program neighborhood for a client node in a client-server network using markup language techniques
US6272493B1 (en) * 1999-01-21 2001-08-07 Wired Solutions, Llc System and method for facilitating a windows based content manifestation environment within a WWW browser
JP3437933B2 (en) * 1999-01-21 2003-08-18 インターナショナル・ビジネス・マシーンズ・コーポレーション Browser sharing method and system
US8095413B1 (en) * 1999-05-07 2012-01-10 VirtualAgility, Inc. Processing management information
US6763371B1 (en) * 1999-05-10 2004-07-13 Telefonaktiebolaget Lm Ericsson (Publ) Method and apparatus for collaborative communication in a communication network
US6988138B1 (en) * 1999-06-30 2006-01-17 Blackboard Inc. Internet-based education support system and methods
US7908602B2 (en) * 1999-06-30 2011-03-15 Blackboard Inc. Internet-based education support system, method and medium providing security attributes in modular, extensible components
US20040153509A1 (en) * 1999-06-30 2004-08-05 Alcorn Robert L. Internet-based education support system, method and medium with modular text-editing component for use in a web-based application
US6675216B1 (en) * 1999-07-06 2004-01-06 Cisco Technolgy, Inc. Copy server for collaboration and electronic commerce
US6691153B1 (en) 1999-08-30 2004-02-10 Zaplet, Inc. Method and system for process interaction among a group
US6523063B1 (en) 1999-08-30 2003-02-18 Zaplet, Inc. Method system and program product for accessing a file using values from a redirect message string for each change of the link identifier
US6507865B1 (en) 1999-08-30 2003-01-14 Zaplet, Inc. Method and system for group content collaboration
US6457045B1 (en) 1999-08-30 2002-09-24 Zaplet, Inc. System and method for group choice making
US6505233B1 (en) * 1999-08-30 2003-01-07 Zaplet, Inc. Method for communicating information among a group of participants
US6598074B1 (en) * 1999-09-23 2003-07-22 Rocket Network, Inc. System and method for enabling multimedia production collaboration over a network
US7249155B1 (en) * 2000-02-09 2007-07-24 International Business Machines Corporation Method for processing a request to multiple instances of a server program
US20020059272A1 (en) * 2000-04-20 2002-05-16 Porter Edward W. Apparatuses, methods, programming, and propagated signals for creating, editing, organizing and viewing collaborative databases
US6809749B1 (en) * 2000-05-02 2004-10-26 Oridus, Inc. Method and apparatus for conducting an interactive design conference over the internet
US7072940B1 (en) 2000-08-14 2006-07-04 Ford Motor Company System and method for managing communications and collaboration among team members
WO2002021413A2 (en) * 2000-09-05 2002-03-14 Zaplet, Inc. Methods and apparatus providing electronic messages that are linked and aggregated
US7299403B1 (en) 2000-10-11 2007-11-20 Cisco Technology, Inc. Methods and apparatus for obtaining a state of a browser
US20020059377A1 (en) * 2000-11-14 2002-05-16 Jagadish Bandhole Collaborative computing systems using dynamic computing environments
US20020077924A1 (en) * 2000-12-20 2002-06-20 Jonathan Spetner System and method for marketing products and services
US20020080171A1 (en) * 2000-12-22 2002-06-27 Laferriere Robert James Method and apparatus for coordinating screen views in a collaborative computing environment
JP2002324037A (en) * 2001-04-24 2002-11-08 Fujitsu Ltd Coordinated display program
US6727930B2 (en) 2001-05-18 2004-04-27 Hewlett-Packard Development Company, L.P. Personal digital assistant with streaming information display
US20030031992A1 (en) * 2001-08-08 2003-02-13 Laferriere Robert J. Platform independent telecollaboration medical environments
US7080124B1 (en) 2001-08-21 2006-07-18 Amazon Technologies, Inc. Digital media resource messaging
US8606916B2 (en) 2001-09-17 2013-12-10 Open Text S.A. Graphical user interface for performing administration on web components of web sites in a portal framework
US8407353B2 (en) * 2001-09-17 2013-03-26 Open Text S.A. Method and system for sharing different web components between different web sites in a portal framework
US20030172077A1 (en) * 2002-03-08 2003-09-11 Mir3, Inc. Device-independent notification system
US8135843B2 (en) * 2002-03-22 2012-03-13 Citrix Systems, Inc. Methods and systems for providing access to an application
WO2003085525A2 (en) * 2002-04-02 2003-10-16 Collabo-Technology, Inc. Method and apparatus for synchronous project collaboration
US7203909B1 (en) * 2002-04-04 2007-04-10 Microsoft Corporation System and methods for constructing personalized context-sensitive portal pages or views by analyzing patterns of users' information access activities
US7668901B2 (en) * 2002-04-15 2010-02-23 Avid Technology, Inc. Methods and system using a local proxy server to process media data for local area users
US7716312B2 (en) 2002-11-13 2010-05-11 Avid Technology, Inc. Method and system for transferring large data files over parallel connections
US7426539B2 (en) 2003-01-09 2008-09-16 Sony Computer Entertainment America Inc. Dynamic bandwidth control
US7208993B2 (en) * 2003-03-11 2007-04-24 Texas Instruments Incorporated Input current leakage correction for multi-channel LVDS front multiplexed repeaters
US8745222B2 (en) * 2003-08-15 2014-06-03 Blackboard Inc. Content system and associated methods
US20050060256A1 (en) * 2003-09-12 2005-03-17 Andrew Peterson Foreign exchange trading interface
IL158282A0 (en) * 2003-10-02 2004-05-12 Netmask El Mar Internet Techno Configuration setting
US8260964B2 (en) 2003-10-02 2012-09-04 Google Inc. Dynamic content conversion
US7493595B2 (en) * 2003-12-19 2009-02-17 The United States Of America As Represented By The Secretary Of The Navy Multiple-user graphical programming and analysis environment
US7650380B2 (en) * 2004-02-12 2010-01-19 International Business Machines Corporation System and method for messaging and collaborating in an intranet environment
US20050234961A1 (en) * 2004-04-16 2005-10-20 Pinnacle Systems, Inc. Systems and Methods for providing a proxy for a shared file system
WO2005119519A2 (en) * 2004-06-02 2005-12-15 Blackboard Inc. Content and portal systems and associated methods
US7987293B2 (en) 2004-10-04 2011-07-26 Netmask (El-Mar) Internet Technologies Ltd. Dynamic content conversion
US7506334B2 (en) * 2005-02-25 2009-03-17 Microsoft Corporation Common, multi-version interface that allows a distributed sybsystem to communicate with multiple versions of the distributed subsystem
US8326659B2 (en) * 2005-04-12 2012-12-04 Blackboard Inc. Method and system for assessment within a multi-level organization
US20070139189A1 (en) * 2005-12-05 2007-06-21 Helmig Kevin S Multi-platform monitoring system and method
US7779004B1 (en) 2006-02-22 2010-08-17 Qurio Holdings, Inc. Methods, systems, and products for characterizing target systems
US7764701B1 (en) 2006-02-22 2010-07-27 Qurio Holdings, Inc. Methods, systems, and products for classifying peer systems
US7933881B2 (en) * 2006-03-17 2011-04-26 Microsoft Corporation Concurrency control within an enterprise resource planning system
US7992171B2 (en) * 2006-09-06 2011-08-02 Qurio Holdings, Inc. System and method for controlled viral distribution of digital content in a social network
US7873988B1 (en) 2006-09-06 2011-01-18 Qurio Holdings, Inc. System and method for rights propagation and license management in conjunction with distribution of digital content in a social network
US7801971B1 (en) 2006-09-26 2010-09-21 Qurio Holdings, Inc. Systems and methods for discovering, creating, using, and managing social network circuits
US7925592B1 (en) 2006-09-27 2011-04-12 Qurio Holdings, Inc. System and method of using a proxy server to manage lazy content distribution in a social network
US7782866B1 (en) 2006-09-29 2010-08-24 Qurio Holdings, Inc. Virtual peer in a peer-to-peer network
US8554827B2 (en) 2006-09-29 2013-10-08 Qurio Holdings, Inc. Virtual peer for a content sharing system
WO2008043182A1 (en) * 2006-10-13 2008-04-17 Ets (Ecole De Technologie Superieure) System for supporting collaborative work
US8494436B2 (en) * 2006-11-16 2013-07-23 Watertown Software, Inc. System and method for algorithmic selection of a consensus from a plurality of ideas
US7886334B1 (en) 2006-12-11 2011-02-08 Qurio Holdings, Inc. System and method for social network trust assessment
US8346864B1 (en) 2006-12-13 2013-01-01 Qurio Holdings, Inc. Systems and methods for social network based conferencing
US7698380B1 (en) 2006-12-14 2010-04-13 Qurio Holdings, Inc. System and method of optimizing social networks and user levels based on prior network interactions
US7730216B1 (en) 2006-12-14 2010-06-01 Qurio Holdings, Inc. System and method of sharing content among multiple social network nodes using an aggregation node
US8548918B1 (en) 2006-12-18 2013-10-01 Qurio Holdings, Inc. Methods and systems for automated content distribution
US8086637B1 (en) 2006-12-22 2011-12-27 Emc Corporation Access control for business process data
US9195996B1 (en) 2006-12-27 2015-11-24 Qurio Holdings, Inc. System and method for classification of communication sessions in a social network
US8489999B2 (en) 2008-09-02 2013-07-16 Accenture Global Services Limited Shared user interface surface system
EP2375694B1 (en) * 2010-03-31 2018-10-24 Sony Interactive Entertainment Europe Limited Networking system and method for a social networking server, client and entertainment device

Citations (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5206934A (en) * 1989-08-15 1993-04-27 Group Technologies, Inc. Method and apparatus for interactive computer conferencing
US5241625A (en) * 1990-11-27 1993-08-31 Farallon Computing, Inc. Screen image sharing among heterogeneous computers
US5434994A (en) * 1994-05-23 1995-07-18 International Business Machines Corporation System and method for maintaining replicated data coherency in a data processing system
US5541911A (en) * 1994-10-12 1996-07-30 3Com Corporation Remote smart filtering communication management system
US5588117A (en) * 1994-05-23 1996-12-24 Hewlett-Packard Company Sender-selective send/receive order processing on a per message basis
US5613124A (en) * 1994-04-15 1997-03-18 Microsoft Corporation Method and system for generating and storing multiple representations of a source object in object storage
US5675796A (en) * 1994-04-08 1997-10-07 Microsoft Corporation Concurrency management component for use by a computer program during the transfer of a message
US5706502A (en) * 1996-03-25 1998-01-06 Sun Microsystems, Inc. Internet-enabled portfolio manager system and method
US5794219A (en) * 1996-02-20 1998-08-11 Health Hero Network, Inc. Method of conducting an on-line auction with bid pooling
US5796396A (en) * 1995-03-31 1998-08-18 Mitsubishi Electric Information Technology Center America, Inc. Multiple user/agent window control
US5812749A (en) * 1996-12-27 1998-09-22 Mci Communication Corporation Method of and system for testing network time protocol client accuracy
US5844553A (en) * 1993-08-30 1998-12-01 Hewlett-Packard Company Mechanism to control and use window events among applications in concurrent computing
US5890963A (en) * 1996-09-30 1999-04-06 Yen; Wei System and method for maintaining continuous and progressive game play in a computer network
US5906598A (en) * 1993-12-22 1999-05-25 Baxter International Inc. Self-priming drip chamber with extended field of vision
US5907598A (en) * 1997-02-20 1999-05-25 International Business Machines Corporation Multimedia web page applications for AIN telephony
US5916302A (en) * 1996-12-06 1999-06-29 International Business Machines Corporation Multimedia conferencing using parallel networks
US5918229A (en) * 1996-11-22 1999-06-29 Mangosoft Corporation Structured data storage using globally addressable memory
US5922044A (en) * 1996-12-13 1999-07-13 3Com Corporation System and method for providing information to applets in a virtual machine
US5924116A (en) * 1997-04-02 1999-07-13 International Business Machines Corporation Collaborative caching of a requested object by a lower level node as a function of the caching status of the object at a higher level node
US5935249A (en) * 1997-02-26 1999-08-10 Sun Microsystems, Inc. Mechanism for embedding network based control systems in a local network interface device
US5944791A (en) * 1996-10-04 1999-08-31 Contigo Software Llc Collaborative web browser
US5959621A (en) * 1996-12-06 1999-09-28 Microsoft Corporation System and method for displaying data items in a ticker display pane on a client computer
US5964660A (en) * 1997-06-18 1999-10-12 Vr-1, Inc. Network multiplayer game
US5974441A (en) * 1995-06-07 1999-10-26 International Business Machines Corporation WWW client server interactive system method with Java (™)
US6018343A (en) * 1996-09-27 2000-01-25 Timecruiser Computing Corp. Web calendar architecture and uses thereof
US6023685A (en) * 1996-05-23 2000-02-08 Brett; Kenton F. Computer controlled event ticket auctioning system
US6029175A (en) * 1995-10-26 2000-02-22 Teknowledge Corporation Automatic retrieval of changed files by a network software agent
US6044205A (en) * 1996-02-29 2000-03-28 Intermind Corporation Communications system for transferring information between memories according to processes transferred with the information
US6044218A (en) * 1997-01-31 2000-03-28 Sun Microsystems, Inc. System, method and article of manufacture for creating a live application or applet development environment
US6065051A (en) * 1998-04-15 2000-05-16 Hewlett-Packard Company Apparatus and method for communication between multiple browsers
US6075863A (en) * 1996-02-28 2000-06-13 Encanto Networks Intelligent communication device
US6094673A (en) * 1998-01-16 2000-07-25 Aspect Communications Method and apparatus for generating agent scripts
US6108687A (en) * 1998-03-02 2000-08-22 Hewlett Packard Company System and method for providing a synchronized display to a plurality of computers over a global computer network
US6128648A (en) * 1994-11-23 2000-10-03 International Business Machines Corporation Information handling system and method for maintaining coherency between network servers and mobile terminals
US6195685B1 (en) * 1998-05-22 2001-02-27 International Business Machines Corporation Flexible event sharing, batching, and state consistency mechanisms for interactive applications
US6253228B1 (en) * 1997-03-31 2001-06-26 Apple Computer, Inc. Method and apparatus for updating and synchronizing information between a client and a server
US6289461B1 (en) * 1998-06-09 2001-09-11 Placeware, Inc. Bi-directional process-to-process byte stream protocol
US6338086B1 (en) * 1998-06-11 2002-01-08 Placeware, Inc. Collaborative object architecture
US6339826B2 (en) * 1998-05-05 2002-01-15 International Business Machines Corp. Client-server system for maintaining a user desktop consistent with server application user access permissions
US6496870B1 (en) * 1997-01-31 2002-12-17 Sun Microsystems, Inc. System, method and article of manufacture for collaboration with an application
US6560707B2 (en) * 1995-11-06 2003-05-06 Xerox Corporation Multimedia coordination system

Patent Citations (41)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5206934A (en) * 1989-08-15 1993-04-27 Group Technologies, Inc. Method and apparatus for interactive computer conferencing
US5241625A (en) * 1990-11-27 1993-08-31 Farallon Computing, Inc. Screen image sharing among heterogeneous computers
US5844553A (en) * 1993-08-30 1998-12-01 Hewlett-Packard Company Mechanism to control and use window events among applications in concurrent computing
US5906598A (en) * 1993-12-22 1999-05-25 Baxter International Inc. Self-priming drip chamber with extended field of vision
US5675796A (en) * 1994-04-08 1997-10-07 Microsoft Corporation Concurrency management component for use by a computer program during the transfer of a message
US5613124A (en) * 1994-04-15 1997-03-18 Microsoft Corporation Method and system for generating and storing multiple representations of a source object in object storage
US5434994A (en) * 1994-05-23 1995-07-18 International Business Machines Corporation System and method for maintaining replicated data coherency in a data processing system
US5588117A (en) * 1994-05-23 1996-12-24 Hewlett-Packard Company Sender-selective send/receive order processing on a per message basis
US5541911A (en) * 1994-10-12 1996-07-30 3Com Corporation Remote smart filtering communication management system
US6128648A (en) * 1994-11-23 2000-10-03 International Business Machines Corporation Information handling system and method for maintaining coherency between network servers and mobile terminals
US5796396A (en) * 1995-03-31 1998-08-18 Mitsubishi Electric Information Technology Center America, Inc. Multiple user/agent window control
US5974441A (en) * 1995-06-07 1999-10-26 International Business Machines Corporation WWW client server interactive system method with Java (™)
US6029175A (en) * 1995-10-26 2000-02-22 Teknowledge Corporation Automatic retrieval of changed files by a network software agent
US6560707B2 (en) * 1995-11-06 2003-05-06 Xerox Corporation Multimedia coordination system
US5794219A (en) * 1996-02-20 1998-08-11 Health Hero Network, Inc. Method of conducting an on-line auction with bid pooling
US6075863A (en) * 1996-02-28 2000-06-13 Encanto Networks Intelligent communication device
US6044205A (en) * 1996-02-29 2000-03-28 Intermind Corporation Communications system for transferring information between memories according to processes transferred with the information
US5706502A (en) * 1996-03-25 1998-01-06 Sun Microsystems, Inc. Internet-enabled portfolio manager system and method
US6023685A (en) * 1996-05-23 2000-02-08 Brett; Kenton F. Computer controlled event ticket auctioning system
US6018343A (en) * 1996-09-27 2000-01-25 Timecruiser Computing Corp. Web calendar architecture and uses thereof
US5890963A (en) * 1996-09-30 1999-04-06 Yen; Wei System and method for maintaining continuous and progressive game play in a computer network
US5944791A (en) * 1996-10-04 1999-08-31 Contigo Software Llc Collaborative web browser
US5918229A (en) * 1996-11-22 1999-06-29 Mangosoft Corporation Structured data storage using globally addressable memory
US5959621A (en) * 1996-12-06 1999-09-28 Microsoft Corporation System and method for displaying data items in a ticker display pane on a client computer
US5916302A (en) * 1996-12-06 1999-06-29 International Business Machines Corporation Multimedia conferencing using parallel networks
US5922044A (en) * 1996-12-13 1999-07-13 3Com Corporation System and method for providing information to applets in a virtual machine
US5812749A (en) * 1996-12-27 1998-09-22 Mci Communication Corporation Method of and system for testing network time protocol client accuracy
US6044218A (en) * 1997-01-31 2000-03-28 Sun Microsystems, Inc. System, method and article of manufacture for creating a live application or applet development environment
US6496870B1 (en) * 1997-01-31 2002-12-17 Sun Microsystems, Inc. System, method and article of manufacture for collaboration with an application
US5907598A (en) * 1997-02-20 1999-05-25 International Business Machines Corporation Multimedia web page applications for AIN telephony
US5935249A (en) * 1997-02-26 1999-08-10 Sun Microsystems, Inc. Mechanism for embedding network based control systems in a local network interface device
US6253228B1 (en) * 1997-03-31 2001-06-26 Apple Computer, Inc. Method and apparatus for updating and synchronizing information between a client and a server
US5924116A (en) * 1997-04-02 1999-07-13 International Business Machines Corporation Collaborative caching of a requested object by a lower level node as a function of the caching status of the object at a higher level node
US5964660A (en) * 1997-06-18 1999-10-12 Vr-1, Inc. Network multiplayer game
US6094673A (en) * 1998-01-16 2000-07-25 Aspect Communications Method and apparatus for generating agent scripts
US6108687A (en) * 1998-03-02 2000-08-22 Hewlett Packard Company System and method for providing a synchronized display to a plurality of computers over a global computer network
US6065051A (en) * 1998-04-15 2000-05-16 Hewlett-Packard Company Apparatus and method for communication between multiple browsers
US6339826B2 (en) * 1998-05-05 2002-01-15 International Business Machines Corp. Client-server system for maintaining a user desktop consistent with server application user access permissions
US6195685B1 (en) * 1998-05-22 2001-02-27 International Business Machines Corporation Flexible event sharing, batching, and state consistency mechanisms for interactive applications
US6289461B1 (en) * 1998-06-09 2001-09-11 Placeware, Inc. Bi-directional process-to-process byte stream protocol
US6338086B1 (en) * 1998-06-11 2002-01-08 Placeware, Inc. Collaborative object architecture

Cited By (78)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7359953B2 (en) 1995-11-13 2008-04-15 Citrix Systems, Inc. Methods and apparatus for making a hypermedium interactive
US8090793B2 (en) 1995-11-13 2012-01-03 Citrix Systems, Inc. Methods and apparatus for making a hypermedium interactive
US6691157B2 (en) 1995-11-13 2004-02-10 Citrix Systems, Inc. Method and apparatus for making a hypermedium interactive
US20040139117A1 (en) * 1995-11-13 2004-07-15 Jeff Muir Methods and apparatus for making a hypermedium interactive
US8285782B2 (en) 1995-11-13 2012-10-09 Citrix Systems, Inc. Methods and apparatus for making a hypermedium interactive
US20020107994A1 (en) * 1999-12-09 2002-08-08 Rickards William S. Collaboration engine: adding collaboration functionality to computer software
US7152220B2 (en) * 1999-12-09 2006-12-19 Sensemaking Technologies Corp. Collaboration engine: adding collaboration functionality to computer software
US8055758B2 (en) 2000-07-28 2011-11-08 Axeda Corporation Reporting the state of an apparatus to a remote computer
US8898294B2 (en) 2000-07-28 2014-11-25 Axeda Corporation Reporting the state of an apparatus to a remote computer
US8108543B2 (en) 2000-09-22 2012-01-31 Axeda Corporation Retrieving data from a server
US7937370B2 (en) 2000-09-22 2011-05-03 Axeda Corporation Retrieving data from a server
US10069937B2 (en) 2000-09-22 2018-09-04 Ptc Inc. Retrieving data from a server
US20100049795A1 (en) * 2000-11-03 2010-02-25 Juniper Networks, Inc. Method and system for providing secure access to private networks
US9444791B2 (en) 2000-11-03 2016-09-13 Pulse Secure, Llc Method and system for providing secure access to private networks
US9130936B2 (en) * 2000-11-03 2015-09-08 Pulse Secure, Llc Method and system for providing secure access to private networks
US9674067B2 (en) 2001-12-20 2017-06-06 PTC, Inc. Adaptive device-initiated polling
US8406119B2 (en) 2001-12-20 2013-03-26 Axeda Acquisition Corporation Adaptive device-initiated polling
US9170902B2 (en) 2001-12-20 2015-10-27 Ptc Inc. Adaptive device-initiated polling
US20030179951A1 (en) * 2002-03-25 2003-09-25 Christiansen Bernd O. Method and apparatus for fast block motion detection
US20060039477A1 (en) * 2002-03-25 2006-02-23 Christiansen Bernd O Method and apparatus for fast block motion detection
US6983020B2 (en) 2002-03-25 2006-01-03 Citrix Online Llc Method and apparatus for fast block motion detection
US8752074B2 (en) 2002-04-17 2014-06-10 Axeda Corporation Scripting of soap commands
US8060886B2 (en) 2002-04-17 2011-11-15 Axeda Corporation XML scripting of SOAP commands
US9591065B2 (en) 2002-04-17 2017-03-07 Ptc Inc. Scripting of SOAP commands
US10708346B2 (en) 2002-04-17 2020-07-07 Ptc Inc. Scripting of soap commands
US9614879B2 (en) 2002-04-22 2017-04-04 Rosebud Lms, Inc. Method and software for enabling N-way collaborative work over a network of computers
US10326807B2 (en) 2002-04-22 2019-06-18 Rosebud Lms, Inc. Method and software for enabling n-way collaborative work over a network of computers
US8578280B2 (en) 2002-04-22 2013-11-05 Rosebud Lms, Inc. Method and software for enabling N-way collaborative work over a network of computers
US20090077474A1 (en) * 2002-04-22 2009-03-19 Rosebud Lms, Inc. Method and Software for Enabling N-Way Collaborative Work Over a Network of Computers
US8046699B2 (en) * 2002-04-22 2011-10-25 Rosebud Lms, Inc. Method and software for enabling N-way collaborative work over a network of computers
US7797403B2 (en) 2002-07-12 2010-09-14 Microsoft Corporation Deployment of configuration information
EP1381186A1 (en) * 2002-07-12 2004-01-14 Microsoft Corporation Deployment of configuration information
US20040010429A1 (en) * 2002-07-12 2004-01-15 Microsoft Corporation Deployment of configuration information
US9002980B2 (en) 2003-02-21 2015-04-07 Axeda Corporation Establishing a virtual tunnel between two computer programs
US7966418B2 (en) 2003-02-21 2011-06-21 Axeda Corporation Establishing a virtual tunnel between two computer programs
US10069939B2 (en) 2003-02-21 2018-09-04 Ptc Inc. Establishing a virtual tunnel between two computers
US8291039B2 (en) 2003-02-21 2012-10-16 Axeda Corporation Establishing a virtual tunnel between two computer programs
FR2861933A1 (en) * 2003-10-30 2005-05-06 Denis Henri Angilella Virtual collaborative environmental system for remote user, has server program processing messages from client programs requesting modification of environment in their reception order and sending modifications in order of reception
US8190679B1 (en) * 2004-05-27 2012-05-29 Adobe Systems, Incorporated Real-time meeting object extensibility
US7163272B2 (en) 2004-06-10 2007-01-16 Lexmark International, Inc. Inkjet print head
US20070103498A1 (en) * 2004-06-10 2007-05-10 Parish George K Inkjet printhead
US8935316B2 (en) 2005-01-14 2015-01-13 Citrix Systems, Inc. Methods and systems for in-session playback on a local machine of remotely-stored and real time presentation layer protocol data
US8422851B2 (en) 2005-01-14 2013-04-16 Citrix Systems, Inc. System and methods for automatic time-warped playback in rendering a recorded computer session
US8230096B2 (en) 2005-01-14 2012-07-24 Citrix Systems, Inc. Methods and systems for generating playback instructions for playback of a recorded computer session
US8200828B2 (en) 2005-01-14 2012-06-12 Citrix Systems, Inc. Systems and methods for single stack shadowing
US8296441B2 (en) 2005-01-14 2012-10-23 Citrix Systems, Inc. Methods and systems for joining a real-time session of presentation layer protocol data
US7921158B2 (en) 2005-12-08 2011-04-05 International Business Machines Corporation Using a list management server for conferencing in an IMS environment
US7827288B2 (en) 2005-12-08 2010-11-02 International Business Machines Corporation Model autocompletion for composite services synchronization
US7792971B2 (en) 2005-12-08 2010-09-07 International Business Machines Corporation Visual channel refresh rate control for composite services delivery
US8005934B2 (en) 2005-12-08 2011-08-23 International Business Machines Corporation Channel presence in a composite services enablement environment
US7809838B2 (en) 2005-12-08 2010-10-05 International Business Machines Corporation Managing concurrent data updates in a composite services delivery system
US8370479B2 (en) 2006-10-03 2013-02-05 Axeda Acquisition Corporation System and method for dynamically grouping devices based on present device conditions
US10212055B2 (en) 2006-10-03 2019-02-19 Ptc Inc. System and method for dynamically grouping devices based on present device conditions
US8769095B2 (en) 2006-10-03 2014-07-01 Axeda Acquisition Corp. System and method for dynamically grouping devices based on present device conditions
US9491071B2 (en) 2006-10-03 2016-11-08 Ptc Inc. System and method for dynamically grouping devices based on present device conditions
US8200764B2 (en) * 2006-12-19 2012-06-12 International Business Machines Corporation System and method for achieving highly scalable real-time collaboration applications using HTTP
US20080147834A1 (en) * 2006-12-19 2008-06-19 Quinn William M System and method for achieving highly scalable real-time collaboration applications using http
US8594305B2 (en) 2006-12-22 2013-11-26 International Business Machines Corporation Enhancing contact centers with dialog contracts
US9712385B2 (en) 2006-12-26 2017-07-18 PTC, Inc. Managing configurations of distributed devices
US9491049B2 (en) 2006-12-26 2016-11-08 Ptc Inc. Managing configurations of distributed devices
US8788632B2 (en) 2006-12-26 2014-07-22 Axeda Acquisition Corp. Managing configurations of distributed devices
US8065397B2 (en) 2006-12-26 2011-11-22 Axeda Acquisition Corporation Managing configurations of distributed devices
US9055150B2 (en) 2007-02-28 2015-06-09 International Business Machines Corporation Skills based routing in a standards based contact center using a presence server and expertise specific watchers
US9247056B2 (en) 2007-02-28 2016-01-26 International Business Machines Corporation Identifying contact center agents based upon biometric characteristics of an agent's speech
US8259923B2 (en) 2007-02-28 2012-09-04 International Business Machines Corporation Implementing a contact center using open standards and non-proprietary components
US20090106347A1 (en) * 2007-10-17 2009-04-23 Citrix Systems, Inc. Methods and systems for providing access, from within a virtual world, to an external resource
US8024407B2 (en) 2007-10-17 2011-09-20 Citrix Systems, Inc. Methods and systems for providing access, from within a virtual world, to an external resource
US20090164500A1 (en) * 2007-12-20 2009-06-25 Ankur Mathur System for providing a configurable adaptor for mediating systems
US8606768B2 (en) * 2007-12-20 2013-12-10 Accenture Global Services Limited System for providing a configurable adaptor for mediating systems
US20090183087A1 (en) * 2008-01-10 2009-07-16 Binfire Corpoartion Method and Apparatus for Real Time Image Transfer Between Two or More Computers
US20100005111A1 (en) * 2008-04-04 2010-01-07 Landmark Graphics Corporation, A Halliburton Company Systems and Methods for Correlating Meta-Data Model Representations and Asset-Logic Model Representations
US20090254569A1 (en) * 2008-04-04 2009-10-08 Landmark Graphics Corporation, A Halliburton Compa Systems and Methods for Real Time Data Management in a Collaborative Environment
US8554778B2 (en) 2008-04-04 2013-10-08 Landmark Graphics Corporation Systems and methods for correlating meta-data model representations and asset-logic model representations
US20110106856A2 (en) * 2008-04-04 2011-05-05 Landmark Graphics Corporation, A Halliburton Company Systems and Methods for Real Time Data Management in a Collaborative Environment
US10552391B2 (en) 2008-04-04 2020-02-04 Landmark Graphics Corporation Systems and methods for real time data management in a collaborative environment
US8229938B2 (en) 2008-04-04 2012-07-24 Landmark Graphics Corporation Systems and methods for correlating meta-data model representations and asset-logic model representations
US10360194B2 (en) 2009-03-13 2019-07-23 Landmark Graphics Corporation Systems and methods for real time data management in a collaborative environment
US8615159B2 (en) 2011-09-20 2013-12-24 Citrix Systems, Inc. Methods and systems for cataloging text in a recorded session

Also Published As

Publication number Publication date
WO1999064959A1 (en) 1999-12-16
JP2002517858A (en) 2002-06-18
EP1110149A4 (en) 2004-06-09
AU4434999A (en) 1999-12-30
EP1110149A1 (en) 2001-06-27
CA2334737A1 (en) 1999-12-16
US6338086B1 (en) 2002-01-08

Similar Documents

Publication Publication Date Title
US6338086B1 (en) Collaborative object architecture
Nichols et al. High-latency, low-bandwidth windowing in the Jupiter collaboration system
US6859821B1 (en) Method and apparatus for prioritizing data change requests and maintaining data consistency in a distributed computer system equipped for activity-based collaboration
Walker et al. Asynchronous remote operation execution in distributed systems
Liskov et al. Communications in the Mercury system
US5675796A (en) Concurrency management component for use by a computer program during the transfer of a message
US6446113B1 (en) Method and apparatus for activity-based collaboration by a computer system equipped with a dynamics manager
US6356933B2 (en) Methods and apparatus for efficiently transmitting interactive application data between a client and a server using markup language
US7337239B2 (en) Atomic message division
US20050071316A1 (en) Method and apparatus for creating, sending, and using self-descriptive objects as messages over a message queuing network
JPH11328132A (en) Data processor for performing operation load management regarding group of servers data processing method tefrefor and computer program product
US11455345B2 (en) Collaboration environments that support offline edits of shared documents
US7680797B1 (en) Methods and systems for providing a data access layer
JP3462064B2 (en) Distributed simulation system
Enokido et al. Group protocol for distributed replicated objects
Gehani Message passing in Concurrent C: Synchronous versus asynchronous
US20090112992A1 (en) Method and system for request processing
Franks et al. Effectiveness of early replies in client–server systems
Kuepper et al. Service Management using up-to-date quality properties
Nehmer et al. Framework for the organization of cooperative services in distributed client-server systems
Ahamad et al. An application of name based addressing to low level distributed algorithms
Pechenizkiy et al. Handling concept drift in medical applications: Importance, challenges and solutions
US7240126B1 (en) Method and system for parsing for use in a server and web browser
Olsen Jr et al. XWeb: An Archictecture for Cross-modal Collaboration
EP0978035B1 (en) Methods and apparatus for managing objects in a distributed environment

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION

AS Assignment

Owner name: MICROSOFT TECHNOLOGY LICENSING, LLC, WASHINGTON

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:MICROSOFT CORPORATION;REEL/FRAME:034766/0001

Effective date: 20141014