METHOD FOR DETERMINATION OF REMOTE ADAPTER AND/OR NODE LIVENESS

• US 20060259619A1
• Filed: 07/26/2006
• Published: 11/16/2006
• Est. Priority Date: 05/08/2001
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schmuck, Frank B., Chang, Chun-Shi, Knop, Felipe, Lin, Tseng-Hui
• Granted Patent: US 7,409,453 B2
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

The determination of node and/or adapter liveness in a distributed network data processing system is carried out via one messaging protocol that can be assisted by a second messaging protocol which is significantly less susceptible to delay, especially memory blocking delays encountered by daemons running on other nodes. The switching of protocols is accompanied by controlled grace periods for needed responses. This messaging protocol flexibility is also adapted for use as a mechanism for controlling the deliberate activities of node addition (birth) and node deletion (death).

Claims

1. A method for determining node status in a network of connected data processing nodes, said method comprising the steps of:

periodically sending, from one of said nodes, to at least one other node in said network, a first message, said first message being directed to a daemon program running on said at least one other node;

determining, at said one of said nodes, that a specified number of first message transmissions have not been received; and

sending a second message to said at least one other node, from said one of said nodes, said second message being directed to another program, running on said at least one other node that is less susceptible than said daemon to being delayed in providing a response.

2. The method of claim 1 in which said other program is part of an operating system kernel running on said at least one other node.

3. The method of claim 1 in which said daemon is prevented from responding within said first specified time period due to memory allocation constraints within said one node.

4. The method of claim 1 in which said daemon is prevented from responding within said first specified time period due to program priority constraints within said one node.

5. The method of claim 1 further including the step of reporting that said one node is dead when there is no response to said second message.

6. The method of claim 1 in which said specified number is 2.

7. The method of claim 1 further including the step of establishing a grace period for a response to said first message when a response to said second message is received.

8. A computer program product stored within or on a machine readable medium containing program means for use in an interconnected network of data processing nodes said program means being operative

to periodically send, from one of said nodes, to at least one other node in said network, a first message, said first message being directed to a daemon program running on said at least one other node;

to determine, at said one of said nodes, that a specified number of first message transmissions have not been received; and

then

to send a second message to said at least one other node, said second message being directed to another program, running on said at least one other node that is less susceptible than said daemon program to being delayed.