Method and apparatus for modifying microcode in a distributed nodal network while the network continues operation

• US 5,649,112 A
• Filed: 01/30/1996
• Issued: 07/15/1997
• Est. Priority Date: 05/11/1994
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wang, David T., Yeager, John D., Stevens, Chester R., Brady, James T., Ho, Lawrence Y.
• Primary Examiner(s): Bowler, Alyssa H.
• Assistant Examiner(s): Rinehart, Mark H.
• Application Number:
  US08/593,551
• Time in Patent Office: 532 Days
• Field of Search: 395/200.07, 395/200.09, 395/200.1, 395/430, 395/700, 395/828, 340/825.05, 340/825.3, 340/825.5, 364/276.3, 364/281.9, 364/280.3, 364/962.1
• US Class Current: 709/220
• CPC Class Codes: G06F 8/656 while running
• CPC Class Codes: G06F 9/24 Loading of the microprogram
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

Updating of control code is accomplished in multiple nodes of a computing system while the computing system remains in operation. Each node includes a processor, memory, a first version of a control code unit and an engineering change level indication for the control code unit. The method comprises the steps of: installing a revised version of the control code unit with converter code modules in a first node, the converter code modules enabling and performing first and second interface functions during communications between the first node and other nodes in the system. The first node is then operated to perform a function which requires communication with other nodes, the converter code module in the first node initially determining an engineering change level value stored in another node and, if the engineering change level values in the nodes match, communicating with the other node through the first interface function. If the engineering change level values are found not to match, communications occur with the other node through the use of the second interface function, enabling both nodes to communicate even though different level code changes are present. A sequencer is also provided in the computing system which enables updating of all nodes in a specified sequence so as to simplify the requirements placed upon the converter code module.

Claims

1. A method for updating a current version of control code in multiple nodes in a computing system while said computing system remains in operation, said computing system operable when a node is removed therefrom, said multiple nodes interconnected by a communications network, each node including a processor, memory, a current version of a control code and a first engineering change level (ECL) value for said current control code, said method comprising the steps of:

a isolating a first node from other nodes in said computing system;

b after said isolating step (a), installing in memory in said first node and operating a new version of control code having a second ECL value and a converter code module, said converter code module operating in conjunction with said processor in said first node to perform a first interface function and a second interface function during communications between said first node and a second node, said first interface function at least enabling communication between current versions of said control code, and said second interface function enabling communication between a current version of said control code and a new version of said control code;

c coupling said first node to other nodes in said computing system;

d operating said first node to perform an action which requires communications with said second node, said converter code module in said first node determining an ECL value stored in said second node and, if ECL values in said first and second nodes match, communicating with said second node through use of said first interface function, and if ECL values in said first and second nodes do not match, communicating with said second node through use of said second interface function which enables said current version of said control code to operate in conjunction with said new version of said control code.

2. The method as recited in claim 1, further comprising the steps of:

e isolating said second node from said computing system;

f installing in memory in said second node, said new version of said control code having a second ECL value and a converter code module, said converter code module operating in conjunction with said processor in said second node to enable and perform first and second interface functions during communications between said second node, first node and other nodes;

g coupling said second node to said computing system; and

h operating said first and second nodes to perform a function which requires communications between said first node, second node and other nodes, said converter code modules, comparing ECL values and, upon finding matching ECL values stored in said first and second nodes, enabling communications therebetween through use of said first interface function, and upon finding non-matching ECL values with said other node, communicating with said other node through use of said second interface function.

3. The method as recited in claim 1, wherein the computing system includes a sequencer code module that defines an order in which revised versions of said control code unit are to be installed in nodes of said computing system, said method including the step of:

installing said revised versions of said control code units on said nodes as specified by said sequencer control module.

4. Apparatus for updating control code in multiple nodes in a computing system while said computing system remains in operation, said computing system operable when a node is removed therefrom, said multiple nodes interconnected by a communications network, each node including a processor, memory, a first version of a control code unit and an engineering change level (ECL) value for said control code unit, said apparatus comprising:

means for installing in memory in a first node a revised version of said control code unit and a converter code module after said first node has been uncoupled from said computing system, said converter code module operating in conjunction with said processor in said first node to perform a first interface function and a second interface function during communications between said first node and a second node, said first interface function enabling communication between nodes with matching ECL values to enable interactive operation of nodes having said first version of said control code unit and said second interface function enabling communication between nodes with non-matching ECL values to enable interactive operation of a node having said first version of said control code unit and a node having said revised version of said control code unit;

means for re-coupling said first node into said computing system and operating said first node to perform a function which requires communications with said second node; and

means for operating said converter code module in said first node to determine an ECL value stored in said second node and, if ECL values in said first and second nodes match, communicating with said second node through use of said first interface function, and if ECL values in said first and second nodes do not match, communicating with said second node through use of said second interface function.

5. Apparatus as recited in claim 4, further comprising:

means for installing a revised version of said control code unit and a converter code module in memory in said second node when said second node is uncoupled from said computing system, said converter code module operating in conjunction with said processor in said second node to enable and perform said first and second interface functions during communications between said second node, first node and other nodes;

means, operable after said second node is recoupled into said computing system, for operating said first and second nodes to perform a function which requires communications between said first node, second node and other nodes; and

means for determining if matching ECL values are stored in said first and second nodes, and if yes, enabling communications therebetween through use of said first interface function in said converter code module, and if non-matching ECL values are found in said second node and said other node, communicating with said other node through use of said second interface function in said converter code module.

6. Apparatus as recited in claim 5, wherein said apparatus includes a sequencer code module that defines an order in which revised versions of said control code unit are to be installed in nodes of said computing system, said apparatus further comprising:

means in each node for operating in conjunction with said sequencer code module for installing said revised versions of said control code unit in the order specified by said sequencer control module.

7. A method for updating control code in multiple nodes in a computing system while said computing system remains in operation, said multiple nodes interconnected by a communications network, each node including a processor, memory, communication means, a first version of a control code unit that is a code module within operating microcode in said node and an engineering change level (ECL) value for said control code unit, said method comprising the steps of:

a isolating a current control code unit from said operating microcode in a first node;

b installing in memory in said first node in place of said current control code unit and operating, a revised version of said control code unit and a converter code module, said converter code module operating in conjunction with said processor in said first node to perform a first interface function and a second interface function when communications occur between said first node and a second node, said first interface function at least enabling communication between current control code units and said second interface function enabling communication between a current control code unit and a revised version of said control code unit;

c operating said first node to perform a function which requires communications with said second node, said converter code module in said first node determining an ECL value stored in said second node and, if ECL values in said first and second nodes match, communicating with said second node through use of said first interface function, and if ECL values in said first and second nodes do not match, communicating with said second node through use of said second interface function, whereby a first node with a current control code unit is able to interact with a second node which has either a current control code unit or a revised control code unit.

8. The method as recited in claim 7, further comprising the steps of:

d isolating said current control code unit from said operating microcode in a second node;

e installing in memory in said second node in place of said isolated control code unit, a revised version of said control code unit and a converter code module, said converter code module operating in conjunction with said processor in said second node to enable and perform said first and second interface functions during communications between said second node, first node and other nodes in said computing system;

f coupling said revised version of said control code unit to operating microcode in said second node; and

g operating said first and second nodes to perform a function which requires communications between said first node, second node and said other nodes, said converter code modules determining ECL values and, upon finding matching ECL values stored in said first and second nodes, enabling communications therebetween through use of said first interface function, and upon finding non-matching ECL values with said other node, communicating with said other node through use of said second interface function.

9. The method as recited in claim 7, wherein the computing system includes a sequencer code module that defines an order in which revised versions of said control code unit are to be installed in nodes of said computing system, said method including the step of:

installing said revised versions of said control code units on said nodes as specified by said sequencer control module.