The system and method of this invention controls how client data processing systems in a distributed networking environment can efficiently extend files and write into regions of the files previously unoccupied by data. The server data processing system manages the distributed allocation of new file blocks by sending nascent zeros in addition to real bytes that have been requested by the client data processing system. Nascent zeros are logically zero bytes that have never been stored to or written to, and may be outside the current extent of the file. The server determines whether or not this additional range of nascent zeros will be sent to a client depending upon the amount of physical storage available at the server, and whether or not other client data processing systems require access to this range of blocks. Likewise, the client data processing system has the option of writing to this additional range of nascent zeros. By writing to the additional range of nascent zeros, a client data processing system can minimize the network traffic overhead used in sending messages to the server data processing system requesting a range of bytes.
This is a continuation of application Ser. No. 07/739,799, filed Aug. 1, 1991, now abandoned which is a continuation of application Ser. No. 07/352,220, filed May 15, 1989, now abandoned.
A distributed file system in which the cache hit ratio of a client is enhanced to speed up a file access for each of users logging into the client. A file server includes an access frequency database in which the names of users are listed in association with the names of files that are frequently accessed by the individual users. Each client includes a log-in user table for entering the name of a user who is logging in, and a cache priority control module. The cache priority control module sets priority levels for the copies of the files stored in a cache area, on the basis of the contents of the access frequency database and the log-in user table. The set priority levels function as criteria when any of the file copies is to be expelled from the cache area. Owing to this construction, the copies of the files of high usage frequencies are preferentially kept in the cache area of the client for each user logging into this client, whereby the cache hit ratio can be enhanced to speed up the file access.
An interprise computing manager in which an application is composed of a client (front end) program which communicates utilizing a network with a server (back end) program. The client and server programs are loosely coupled and exchange information using the network. The client program is composed of a User Interface (UI) and an object-oriented framework (Presentation Engine (PE) framework). The UI exchanges data messages with the framework. The framework is designed to handle two types of messages: (1) from the UI, and (2) from the server (back end) program via the network. The framework includes a component, the mediator which manages messages coming into and going out of the framework. The system includes software for a client computer, a server computer and a network for connecting the client computer to the server computer which utilize an execution framework code segment configured to couple the server computer and the client computer via the network, by a plurality of client computer code segments resident on the server, each for transmission over the network to a client computer to initiate coupling; and a plurality of server computer code segments resident on the server which execute on the server in response to initiation of coupling via the network with a particular client utilizing the transmitted client computer code segment for communicating via a particular communication protocol. Communication is initiated utilizing the network to acquire characteristics of the client from the network.
A shopping cart metaphor is emulated on a network of server and client computing systems. A browser at the client station has a request module to send a shopping page request to the server. A shopping page module in the server sends a shopping page file to the browser in response to the shopping page request. The shopping page file contains items selectable by a user using the browser. A shopping module at the browser generates an add request and sends the add request to the server. This add request contains selected items from the items that were selectable in the shopping page file. A receiver at the server receives the add request from the browser, and a cart list module at the server initializes a shopping cart list. An add module at the server adds the selected items to the shopping cart list. A shopping page module at the server converts the cart list to a cart field, generates a new shopping page file, embeds the cart field in the new shopping page file and sends the new shopping page file to the browser. In this way, the shopping cart field is in a shopping page file that may be managed by the browser at the client station.
A method and apparatus for controlling data flow on a network having a server and a non-blocking client node in which the client node may not drop requests received from the server. A process on the non-blocking client node allocates resources on the non-blocking client node and notifies the server of the allocated resources. The server then determines the resources on the non-blocking client node required to fulfill a request by an application on the server and whether sufficient resources are available on the non-blocking client node to fulfill the request by the application. If sufficient resources are available, the server then sends the request to the client node and if sufficient resources do not exist, the server waits until sufficient resources do exist to issue the request to the non-blocking client node.
Heterogeneous data at a plurality of remote nodes is accessed automatically in parallel at high speed from a user site using a simple script request containing a data source object name wherein the heterogeneous data is treated as a single data source object, the script further containing at least one method to be performed on the data source object. Respective agent processes at the user site and at the remote nodes automatically generate descriptor files containing metadata corresponding to the data source object. The user site agent breaks the user-generated script into new scripts appropriate for execution at the remote nodes. A messenger process transmits the new scripts to the appropriate remote nodes where respective agent processes respond to automatically access the appropriate data and execute specified methods upon it.
