Hitachi, Ltd.

Hisashi Hashimoto

Masayuki Orimo

Shigeki Hirasawa

Nobuyoshi Andou

Kinji Mori

Katsumi Kawano

Shinji Kimura

Satoshi Kikuchi

Keiichi Nakane

Takeiki Aizono

Hiromichi Ito

Satoshi Oshima

Atsushi Kobayashi

Yusuke Hino

Koki Nakashiro

Eisaku Nishiyama

Hiroshi Fujise

Seiichi Domyo

Yumiko Sugita

Tomihiko Kojima

Hidehiko Akita

Toshiro Nose

Tsutomu Miyairi

Masato Manda

Masaki Tsuruki

Yutaro Hori

The present invention provides a technique of controlling cache operation on a node device in a computer system that enables transmission and receipt of data between clients and a storage device via the node device. In accordance with a first control method, the data stored in the storage device includes attribute data, as to whether or not the data is cacheable. This application enables the node device to relay non-cacheable data without process of the cache. In accordance with a second control method, the node device encrypts the data when caching the data in the disk. In accordance with a third control method, non-cacheable data is transmitted and received directly without going through the node device. These applications enable the cache in the node device to be restricted, and thereby ensure security.

Cache control method for node apparatus

The technique of the present invention enhances reading speed of data from a disk device in a computer system capable of transmission and reception of the data via a node devicebetween a clientand a storage device. A share volume PDc and specific volumes PDa and PDb are defined in the disk device on the storage device. Common data among respective clients and specific data corresponding to the individual client are stored in the share volume and specified volumes, respectively. Once respective clients request virtual volumes VDa and VDb to read the data, the storage device reads out the corresponding data from the share volume or the specific volume. This application avoids lowering the reading speed regardless of the concentration of accesses from a plurality of clients because most data can be read from the share volume.

Method and apparatus for a data source device with shared storage for a plurality of clients

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 database management system includes a communication network, at least a terminal device including an application program execution unit connected to the communication network, a plurality of information processors connected to the communication network, a plurality of physical databases installed in at least one of the information processors, at least a logical database grouping a plurality of the, physical databases, the logical database being defined by logical database information stored in at least one of the terminal device and the plurality of information processors, at least a table stored in at least one of the physical databases, and a table location searching unit installed in at least one of the terminal device and the plurality of information processors, for searching a table stored in at least one of the physical databases based on the logical database information, the table being requested to access on a logical database, from the application program execution unit.

Distributed database management system including logical database constituted by a group of physical databases

An information processing system and a communication method performed in the information processing system for performing data transmission effectively. The information processing system includes a plurality of information processing apparatuses and a communication line for interconnecting the plurality of information processing apparatuses. A sending information processing apparatus, when sending information to the plurality of information processing apparatuses, sends transmission information to one of the plurality of information processing apparatuses. The one information processing apparatus sends the received transmission information to the other information processing apparatuses of the plurality of information processing apparatuses.

Method and apparatus for providing communication between grouped

A database access system for a distributed system, in which the database access load is distributed among a plurality of gateways, and an arbitrary character code set can be used for database access. After the lapse of a predetermined time length, processings for particular database access are terminated. An error of a DBMS or a component on the gateway is detected by a client. The gateway detects an error of the client in connection. The client notifies the character code set identification information of the character code used for outputting the request to the gateway, and the gateway converts the character code for the request and a response to the client. The gateway receives an access request, secures the connection with a database access language conversion unit, and sends the language converted to a DBMS. In the absence of a response after the lapse of a predetermined time length, the connection with the database access language conversion unit is terminated and an error is notified to the client. Also, an error monitor request is outputted at regular intervals of time, and an error is notified to the client in the case where there is no response to the error monitor request after the lapse of a predetermined time length.

Database access system and method of controlling access management to a

An object management system is equipped with a single real object management system for managing a real file object such as data and a program based on a real directory object in a hierarchical structure, and also at least a single virtual object management system for managing a virtual file object corresponding to said file object based upon a virtual directory object which is independent of the directory object in a hierarchical structure.

Virtual object management system for managing virtual objects which

A data processing system including a display unit for displaying a plurality of graphic patterns and names thereof corresponding to resources, and an input unit for selectively designating objects to be processed from graphic patterns or names being displayed. A file is provided for registering the graphic patterns and names corresponding to the resources in connection with each user. The graphic patterns and the names thereof specific to a user are read out from the file on the basis of user identifying information inputted in precedence to the data processing and this read out data is displayed on the display unit.

Data processing system capable of executing data processing using

The present invention is directed to time-sharing computer system which includes a host computer system which operates in response to a host TSS command, a terminal computer system which is connected to the host computer system through a line and operates in response to a terminal TSS command, and a plurality of terminals which are connected to the terminal computer system. In this time-sharing system, the data processing in a terminal computer in response to a terminal TSS command input and the subsequent data processing in the host computer system in response to a host TSS command input can be carried out freely when the terminal is in a state of interaction with the host computer, without carrying out an end command of the host TSS a mode exchange operation. For this purpose, the system adopts the concept of a multiplexed TSS, which enables plural sessions to be simultaneously executed by the host computer system and the terminal computer system.

Time-sharing computer system operable in a host TSS mode and a terminal

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Yokohama, Japan

Hisashi Hashimoto