Abstract: A method, system, and computer-readable code with which a scheduling system can be implemented that allows a sender and a receiver to change priorities of queued messages. A technique is also defined for providing a receiver with an advance notice of intended message priority, enabling the receiver to request a priority change before transmission begins. These techniques provide the flexibility to respond to changes in dynamic, volatile network environments, as well as changes in user's wishes or requirements. A ranking technique is defined, whereby requests to change priority may be accepted or denied through a ranking algorithm that resolves potential conflicts in desired transmission priority using proposals exchanged by the parties (e.g. during connection establishment).

Abstract: A method, system, and computer-readable code for embedding a file index among the fixed-length data blocks of a random-access file to which the index pertains. In the preferred embodiment, a B-tree index is used. The nodes of the B-tree are stored using blocks of the random-access file, so that the index records are embedded among the data records to which the index pertains. This technique avoids a number of problems that result when a data file and its index are separately located. Record updates and retrievals operate more efficiently, and the data records remain synchronized with the corresponding index when file operations (e.g., close, flush) complete successfully. In an optional enhancement, synchronization is ensured when record-level operations (write, delete) complete successfully.

Abstract: Method, apparatus and program products are provided for persistent cache synchronization for a first communication session and a concurrent second communication session over an external communication link between a client protocol conversion application executing on a first computer and a server protocol conversion application executing on a second computer located remote from the first computer. An active cache is established independently for each session with a corresponding cache for each session at the other computer for use with the first and the second communication session respectively. A checkpoint request is transmitted to the server application indicating one of the active protocol caches from either the first session or the second session to be used to provide a checkpoint. On receipts of the request from the server application, the active protocol cache for the indicated session is copied to provide a checkpoint cache of the second computer.

Abstract: A method of updating or rebasing templates for information sent across a relatively slow transmission link such that only changed information is transmitted across the links. In addition, the information is updated such that the information transmitted across the links is minimized by updating the templates based on the characteristics of the data being sent.

Abstract: A method of communicating between computers, particularly between a host connected to a network server, and a workstation client running a terminal emulator. A pre-warmed cache is generated, containing information used in common by emulation programs on the client and server. The pre-warmed cache can be loaded on the client, e.g., when establishing a session with the server. The pre-warmed cache may be generated by executing an application on the host, transmitting at least one terminal data stream associated with the application to the server (or to a second server configured substantially similar to the first server) and building a cache instance using one or more portions of the terminal data stream. A single pre-warmed cache can be provided for different hosts.

Abstract: A method and system for efficiently updating container objects on remote systems. The method and system involve a server extension which determines whether the files within the container object have changed since the last time they were sent to the client. If they have changed, the server extension sends only the changed files with instructions on how to reconstruct the container object to a client extension. The client extension receives the changes and the instructions and reconstitutes the container object and transmits the container object to the client browser.

Abstract: A method of updating or rebasing templates for information sent across a relatively slow transmission link such that only changed information is transmitted across the links. In addition, the information is updated such that the information transmitted across the links is minimized by updating the templates based on the characteristics of the data being sent.

Abstract: Methods, systems and computer program products which provide for communicating with a web browser executing on a remote/mobile processing system which is temporarily and intermittently connected to a second computer by storing in a persistent request queue at the second computer, a request from the web browser to a server application accessible to the second computer. Also disclosed are methods, systems and computer program products which allow for operation and management of asynchronous operations of a web browser where the operations are carried out by a server-side intercept module.

Abstract: Method, appartus and program products for persistent cache synchronization for communications over an external communication link between a client protocol conversion application executing on a first computer and a server protocol conversion application executing on a second computer located remote from the first computer are provided. Protocol conversion applications are provided on both the host side and the terminal side of the external communication link to provide communications over the external communication link using a differenced communication data stream which includes a reduced volume of data for transmittal. A checkpoint is provided to allow for improved performance on start up of a new communication session over the external communication link between the client application and the server application by initiating a checkpoint request and transmitting the request from the client to the server.

Abstract: Methods, systems and computer program products are provided for error recovery in a network having a first application associated with a first endpoint node and a second application associated with a second endpoint node. These methods, systems and computer program products non-disruptively switch the first application associated with the first endpoint node to a third endpoint node arbitrarily selected from existing endpoint nodes when the first endpoint node is no longer available to the second application associated with the second endpoint node. The first application is provided on the third endpoint node in substantially the same state as the first application existed on the first endpoint node prior to the unavailability of the first endpoint node. The present invention is preferably carried out where the endpoint nodes are VTAM facilities. Also, the first and third endpoint nodes are VTAM facilities in the same SYSPLEX.

Abstract: Methods, systems and computer program products are provided for communicating with a web browser executing on a remote/mobile processing system which is temporarily and intermittently connected to a second computer. According to the present invention, requests from the web browser to a server application accessible to the second computer are stored in a persistent request queue at the remote/mobile processing system. An interim response is provided to the web browser in response to the request from the client application. The stored request may be recalled to allow user modification of the stored request prior to the request being provided to the second computer for transmission to the server application.

Abstract: A method, apparatus and computer program product for reducing the data transmitted over a communication link from a first application resident in a first computer and to a second application resident in a second computer wherein the data is transmitted over an external communication link. HTML data in response to specific data in a CGI request is stored in a cache resident in the first computer to create a server base cache entry. HTML data in response to the specific data in the CGI request is also stored in a cache resident in the second computer to create a client base cache entry. CGI requests and specific CGI data is evaluated to determine if a corresponding client base cache entry exists to provide a client base form. CGI requests and specific CGI data are interrogated to determine if a server base cache entry exists to provide a server base form. The data stream corresponding to the response HTML data is intercepted and compared to the server base form to provide difference data.

Abstract: Method, apparatus and program products for increasing the performance of communications of a terminal emulator application resident on a first computer and communicating over an external communication link using a terminal emulator protocol with a host application resident on a second computer remote from the first computer are provided. A protocol interceptor is provided on both the host side and the terminal emulator application side of the external communication link to provide communications over the external communication link using a differenced communication protocol data stream which includes a reduced volume of data for transmittal compared to the corresponding terminal emulator protocol data stream. The reduction in volume in the differenced communication protocol data stream is based on recognition and replacement of data segments which have previously been transmitted by the host application.

Abstract: Method, apparatus and program products are provided for persistent cache synchronization for a first communication session and a concurrent second communication session over an external communication link between a client protocol conversion application executing on a first computer and a server protocol conversion application executing on a second computer located remote from the first computer. An active cache is established independently for each session with a corresponding cache for each session at the other computer for use with the first and the second communication session respectively. A checkpoint request is transmitted to the server application indicating one of the active protocol caches from either the first session or the second session to be used to provide a checkpoint. On receipt of the request from the server application, the active protocol cache for the indicated session is copied to provide a checkpoint cache of the second computer.

Abstract: A method, apparatus and computer program product for caching data received from a first application and to be provided to a second application in response to a request from the second application. The method apparatus and computer program products including storing a data stream to be received from the first application and to be provided to the second application in a cache to create a client cache entry corresponding to the request from the second application. The time of creation of a client cache entry is also stored to create a client cache entry time record. Requests from the second application are interrogated to determine if a client cache entry exists corresponding to the request.

Abstract: A method, apparatus and computer program product for reducing the data transmitted over an external communication link using the TCP protocol from a first application resident in a first computer and to a second application resident in a second computer. The method, apparatus and computer program product include establishing a first virtual socket in the first computer in response to each connection request by the first application for receiving request data originated by the first application. A first real socket in the first computer and a second real socket in the second computer are established to connect the first computer to the second computer over the external communication link and are maintained until the request data has been provided to the second application.

Abstract: A method, apparatus and computer program product for reducing the data transmitted over an external communication link from a first application resident in a first computer to a second application resident in a second computer. The method, apparatus and computer program product include storing a data stream from the first application to be provided to the second application in response to a request from the second application in a cache resident in the first computer to create a server base cache entry and in a cache resident in the second computer to create a client base cache entry. Requests from the second application are interrogated to determine if a client base cache entry corresponding to the interrogated request exists and to determine if a server base cache entry corresponding to the interrogated request exists.

Abstract: A method, apparatus and program product for increasing the performance of a client/server system having a client application resident on a first computer and communicating with a server application resident on a second computer remote from the first computer. The client application and the server application utilize a client/server independent communication protocol for communication between the client and the server and at least one segment of the communication between the client application in the first computer and the server application in the second computer occurs over an external communication link. The method, apparatus and program product intercept communications in the client/server independent communication protocol originated by the remote client prior to transmission of the communications on the external communication link and convert the communication originated by the client to a second client/server specific communication protocol.

Abstract: Packet messages transmitted on a packet communications network include origin and destination addresses in the form of stacked address elements which can be pushed or popped off of the stack. A plurality of interconnected packet communications network include routing nodes which utilize the top address element on the destination stack to route the message. Such routing nodes also include stack element editing facilities for popping elements from the stocks, constructing new elements to be pushed onto the stacks, and amending the contents of elements on the stack. This arrangement allows messages to be launched on the networks where the originating station does not have full knowledge of the destination station, and the routing nodes add the necessary destination information as it becomes necessary for routing.