公开(公告)号：DE3850978D1

公开(公告)日：1994-09-15

申请号：DE3850978

申请日：1988-01-26

Applicant: IBM

Inventor： JOHNSON DONOVAN WILLIAM ,  SHAHEEN-GOUDA AMAL AHMED ,  SMITH TODD ALLEN

IPC: G06F15/16 ,  G06F9/46 ,  G06F9/52 ,  G06F12/00 ,  G06F15/177 ,  G06F17/30 ,  G06F15/40

公开(公告)号：DE3889739D1

公开(公告)日：1994-07-07

申请号：DE3889739

申请日：1988-01-26

Applicant: IBM

Inventor： CHANG ALBERT ,  SHAHEEN-GOUDA AMAL AHMED ,  NEUMAN GROVER HERBERT ,  SMITH TODD ALLEN

IPC: G06F12/00 ,  G06F12/08

Abstract: In a distributed environment several data processing systems are interconnected across a network system (3). A distributed services program installed on the systems in the network allows the processors to access data files (5) distributed across the various nodes (A,B) of the network without regard to the location of the data file in the network. The processing system accessing the file, referred to as the client processing system, utilizes a client cache (12B) within its operating system (11B) to store the data file. Utilizing the client cache minimizes the number of reads and writes that must go over the network (3) to the server processing system where the file physically resides. The system and method of this invention prevents a process in the client processing system from accessing data in the client cache that has been modified at another node (A) in the network. The blocks of data in the client cache (12B) are tested for validity in the client processing system by using modification times as measured by the server processing system. If the cache data blocks are determined to be valid, the data is accessed from the client cache. If the cache data blocks are determined to be invalid, the data blocks are discarded, and the file is accessed from the server processing system.

公开(公告)号：BR8800330A

公开(公告)日：1988-09-13

申请号：BR8800330

申请日：1988-01-28

Applicant: IBM

Inventor： JOHNSON DONAVON W ,  SHAHEEN-GOUDA AMAL AHMED ,  SMITH TODD ALLEND

IPC: G06F12/00 ,  G06F12/08 ,  G06F13/00 ,  G06F15/16 ,  G06F17/30 ,  H04L29/00

Abstract: A directory management technique is provided for a plurality of data processing systems which are connected together in a network. In the system, when a local, or client, data processing system interrogates a remote, or server, data processing system for a unit of directory information, the server system is enabled to automatically send additional units of pertinent directory information back to the client system in response to a subsequent change in the directory structure of the server system. If the server system is unable to continue updating the client system, for any of a plurality of possible reasons, the server system informs the client system of this fact, which enables the client system to purge itself of the formerly stored directory cache entry relative to this path, since the client system can no longer consider this cached path information to be currently correct.