System for locating resources resided in a distributing processing system by sequentially transmitting resource inquiries through a looped transmission line

• US 4,941,084 A
• Filed: 05/27/1988
• Issued: 07/10/1990
• Est. Priority Date: 09/14/1984
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Takagi, Satoru, Wataya, Hiroshi, Sueki, Masao, Terada, Matsuaki
• Primary Examiner(s): Lee, Thomas C.
• Application Number:
  US07/201,290
• Time in Patent Office: 774 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 340/825.07, 340/825.52, 340/825.05, 370/60, 370/82, 370/94
• US Class Current: 718/104
• CPC Class Codes: G06F 15/17337 Direct connection machines, e.g. completely connected computers, point to point communication networks coupling between buses G06F13/4004
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A resource management system and method in a distributed processing system in which a plurality of computers are interconnected through a transmission line. A computer makes, upon accessing to a resource of another computer, inquiries about "Whether the intended resource exists" and "Ordering that if the intended resource exists, the interrogated computer should return a response indicative of attribute information of that resource" by using a so-called broadcasting function to simultaneously apprize all the computers constituting the distributed processing system of the same message.

Claims

1. A resource management system in a distributed processing system, said management system comprising:

a plurality of arithmetic processing means;

at least one resource belonging to each arithmetic processing means;

a unidirectional looped transmission line interconnecting said plurality of arithmetic processing means for exchanging information therebetween; and

storage means provided in each of said plurality of arithmetic processing means, for storing a resource management table which registers an identification code and attribute information of a resource belonging to said arithmetic processing means, said attribute information including information for specifying a location of said resource; and

a first one of said plurality of arithmetic processing means including means for effecting an inquiry through said transmission line, to all other arithmetic processing means to determine whether any one of said other arithmetic processing means contains a resource represented by an identification code desired by said first arithmetic processing means;

wherein, said inquiry being performed by sending an inquiry request from said first one of said arithmetic processing means to a second arithmetic proceeding means of said other arithmetic processing means, determining by said second arithmetic processing means whether a resource requested by said inquiry request is contained therein, and if said requested resource is not contained in said second arithmetic processing means sequentially passing said inquiry request to each of said other arithmetic processing means until said requested resource is found; and

wherein each of said other arithmetic processing means includes means for making reference to the resource management table contained therein to examine whether it contains the desired resource and means for effecting a response processing to transmit, through said transmission line, an identification code and attribute information of said desired resource to said first arithmetic processing means when said reference means detects said desired resource so that said first arithmetic processing means can access said desired resource by using said attribute information.

2. A resource management system according to claim 1, wherein said first arithmetic processing means further comprises a cache table in which said identification information and attribute information provided by one of said other arithmetic processing means are stored, said first arithmetic processing means including means for searching said cache table prior to effecting said inquiry processing and for omitting said inquiry processing when it is determined from a search of said cache table that said attribute information of said desired resource has already been stored in said cache table.

3. A resource management system according to claim 2, wherein the contents of said cache table are purged when said one of said other arithmetic processing means is withdrawn from said distributed processing system.

4. A resource management method in a network system having a plurality of stations interconnected through a transmission unidirectional looped line, each station being connected to a data processing means for managing at least one resource, comprising the steps of:

broadcasting an inquiring message inquiring as to a location of a requested resource from a first one of said data processing means to said transmission line through a first station connected with said first data processing means when a request is made by an application program of said first data processing means to access a resource not under the management of said first data processing means;

receiving said inquiring message within a data processing means of other data processing means connected to said transmission line;

examining a resource management table included in said data processing means to determine whether the requested resource is under the management thereof;

suquentially passing said inquiry message to other data processing means connected to said transmission line until said requested resource is found;

sending a response message containing attribute information of said requested resource back to said first data processing means, from a second data processing means of said other data processing means, when said requested resource is determine to be under management of said second data processing means; and

sending an accessing message for accessing said requested resource from said first data processing means to said second data processing means using said attribute information contained in said response message when a response message is sent from said second data processing means to said first data processing means.

5. A resource management method according to claim 4, wherein said attribute information contained in said response message includes physical identification information of said requested resource.