Hitachi, Ltd.

Atsushi Kobayashi

Kinji Mori

Katsumi Kawano

Masayuki Orimo

Shigeki Hirasawa

Takeiki Aizono

Yukio Nakata

Hisashi Hashimoto

Toru Horimoto

Koki Nakashiro

Nobuyoshi Andou

Hidemitsu Higuchi

Takaki Kuroda

Keiichi Nakane

Satoru Tezuka

Seiichi Domyo

Yukio Shimamoto

Kimitoshi Yamada

Itaru Isobe

Naofumi Shouji

Katsuhiro Ono

Masahiko Haraguchi

Hirohiko Nakano

In a distributed processing system including a plurality of programs distributed in a plurality of processing units and in which a program on reception side performs processing using a message transmitted from a program on transmission side, a management table for managing start of programs on reception side is provided in a processing unit in which the program on reception side is provided. A program utilizing the message transmitted from the transmission side is recognized and the recognized program is started at the start timing indicated in the management table. The start timing of the program set in the management table may be registered previously or the message may include information indicating the start timing.

Execution management method of program on reception side of message in distributed processing system

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.

Distributed file system permitting each user to enhance cache hit ratio

A distributed information processing system which includes a server having a resume-request processor and clients having resume-request units or processor. An user at the client site operates a resume switch to save an operation state of the client in the server's magnetic disc, and resume it from the server's magnetic disc. The operation state includes contents of the main memory, contents of the display memory, values of the I/O registers for peripheral devices, and information about the file of the server being used by the application program run by the user. The user is able to use any client of the system in the same situation including a connection state between the file and the application program as before.

Distributed information processing system providing a resume function

A multi-protocol communication control apparatus which includes a plurality of kinds of upper layer protocol controllers, a plurality of kinds of lower layer protocol controllers, and a common interface controller for processing correspondence between the upper and lower layer protocols controllers. The multi-protocol communication control apparatus provides for the optional use of any combination of a plurality of kinds of upper layer communication protocols, a plurality of kinds of lower layer communication protocols, and a plurality of transmission lines.

Multi-protocol communication control apparatus

A method of managing, in a network system having at least two end systems, at least two networks respectively connected to the at least two end systems and at least one transfer device for connecting the networks and transferring data between the networks, a maximum transfer unit of one unit of data transferred at time on a transfer route connected between the two end systems and including the networks and the transfer device. A table is provided having information about the transfer route in each of the end systems and the transfer device, and an optimum value of maximum data lengths of the one unit of data which are transferable on the transfer route is registered, as the maximum transfer unit for the transfer device, in each of the tables. In particular, the optimum value is a minimum value of maximum data lengths of the one unit of data which are transferable through each of the networks on the transfer route.

Network system and method of managing a maximum transfer unit in the

In communication which uses a communication line which allows the determination of a communication protocol in a communication port prior to the communication like in an ISDN network, a communication program corresponding to the determined communication protocol is dynamically linked and initialized to allow dynamic selection of the communication protocol.

Protocol selector and protocol selection method

Growing community of inventors

Hadano, Japan

Atsushi Kobayashi