Multicomputer complex having a distributed shared memory system for providing a single system view from multiple consoles

• US 5,390,316 A
• Filed: 07/30/1993
• Issued: 02/14/1995
• Est. Priority Date: 08/31/1990
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Vignola, Christopher P., Johnson, Jon K., Mohan, Ramu, Kong, John P. S., Gates, John T. Jr., Cramer, Lorraine, Fagen, Scott A.
• Primary Examiner(s): Dixon, Joseph L.
• Assistant Examiner(s): Nguyen, Hiep T.
• Application Number:
  US08/100,639
• Time in Patent Office: 564 Days
• Field of Search: 395/400, 395/425, 364/200 MS File, 364/900 MS File
• US Class Current: 709/201
• CPC Class Codes: G06F 3/14 Digital output to display device ; Cooperation and interconnection of the display device with other functional units
• CPC Class Codes: G06F 3/1423 controlling a plurality of local displays, e.g. CRT and flat panel display
• CPC Class Codes: G09G 2360/04 Display device controller operating with a plurality of display units

Abstract

A computer complex is provided with a mechanism for message delivery and redelivery in a controlled manner through the use of distributed shared memory. This provides a mechanism for overall computer system complex operation from a plurality of consoles which are registered or identified to the system and which particularly enhances capabilities for remote operation. In this way the complex can be made to look like a single system. Direct communication between any pair of systems is provided, say, by channel-to-channel adapters. Message information is maintained in each system which can also communicate with shared storage to establish update level information regarding locally maintained message information.

Claims

1. A computer system complex operable from a plurality of consoles, said computer system complex comprising:

a plurality of computer systems, each possessing means for storing redirectable message signals;

channel means linking said computer systems for transferring message signals between computer systems for within said computer system complex;

shared storage means, accessible by said computer systems, for storing system complex wide state information;

means for associating system complex wide unique identification information with said message signals which are generated within said computer systems for display at consoles attached thereto, said message signals being for transmission to the same or another of said computer systems, said system complex wide unique identification information being part of said system complex state information; and

means for serializing access to said system complex wide state information to assure consistency of information contained within control blocks within the internal storage of at least two of said computer systems.

2. The computer system complex of claim 1 in which said channel means comprises channel-to-channel adapters.

3. The computer system complex of claim 1 in which said system complex state information includes message sequence data,

4. The computer system complex of claim 1 in which said system complex state information includes said unique identification information,

5. The computer system complex of claim 4 in which said unique identification information comprises a message sequence number,

6. The computer system complex of claim 1 in which said shared memory means comprises at least one direct access storage device,

7. The computer system complex of claim 1 further including means, residing within at least one of said computer systems, for redirection of said message signals to other computer systems available for its receipt.

8. The computer system complex of claim 7 in which said message signals include an update status indication.

9. The computer system complex of claim 1 further including means residing within at least one of said computer systems, for determining which message signals are delivered to at least one of said consoles.

10. A method for operating a computer system complex having a plurality of separate computer systems and having channel means for direct communication between at least two of said computer systems and also having shared storage means accessible by said computer systems, wherein a plurality of consoles are each respectively coupled to one of said computer systems for the purpose of entering commands and receiving message signals, said method comprising the steps of:

providing serialized access to system complex wide state information stored on said shared storage means;

maintaining consistency of said system complex wide state information by checking local versus system complex wide state information and refreshing both local status information and said system complex wide state information as necessary by acquiring the correct system complex wide state information from another of said computer systems;

transmitting said computer system complex wide state information, through said channel means, from one of said computer systems in said complex to at least one other of said computer systems, said system complex wide state information being updated after said transmission is complete; and

updating said locally stored control block structures in response to said system complex wide state information, so as to maintain consistency system complex wide state information.