Method and system to detect software faults

• US 7,260,741 B2
• Filed: 09/18/2001
• Issued: 08/21/2007
• Est. Priority Date: 09/18/2001
• Status: Expired due to Term

• Current Assignee: Genband US LLC (Ribbon Communications, Inc.)
• Original Assignee: Cedar Point Communications Incorporated
• Inventors: Fitzgerald, Jeffrey J.
• Primary Examiner(s): Beausoliel, Robert
• Assistant Examiner(s): PUENTE, EMERSON C
• Application Number:
  US09/954,731
• Publication Number:
  US 20030056152A1
• Time in Patent Office: 2,163 Days
• Field of Search: 714/38, 714/47, 714/55, 714 10- 13, 702/186, 702/187
• US Class Current: 714/13
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 11/0751 Error or fault detection not based on redundancy power supply failures G06F1/30; network fault management H04L41/06
• CPC Class Codes: G06F 11/1479 Generic software techniques for error detection or fault masking
• CPC Class Codes: G06F 11/1637 using additional compare functionality in one or some but not all of the redundant processing components
• CPC Class Codes: G06F 11/182 based on mutual exchange of the output between redundant processing components
• CPC Class Codes: G06F 11/2023 Failover techniques
• CPC Class Codes: G06F 11/301 where the computing system is a virtual computing platform, e.g. logically partitioned systems virtual machines G06F9/45533; logical partitioning of resources G06F9/5077
• CPC Class Codes: G06F 11/3017 where the computing system is implementing multitasking multiprogramming arrangements G06F9/46; allocation of resources G06F9/50
• CPC Class Codes: G06F 11/302 where the computing system component is a software system
• CPC Class Codes: G06F 11/3024 where the computing system component is a central processing unit [CPU]
• CPC Class Codes: G06F 11/3055 Monitoring arrangements for monitoring the status of the computing system or of the computing system component, e.g. monitoring if the computing system is on, off, available, not available error or fault processing without redundancy G06F11/0703; error detection or correction by redundancy in data representation G06F11/08; error detection or correction by redundancy in operation G06F11/14; error detection or correction by redundancy in hardware G06F11/16

Abstract

The present invention is directed to a system and method for actively auditing a software system to determine the status. The software system includes a plurality of processes executed in an active processor domain. An active message is generated for processing in the active processor domain. Each process receiving the message modifies it by adding an active time indicator to it; thereby creating a modified active message. The status of the active processor domain is determined in response to the modified active message.

Claims

1. A method of enhancing fault tolerance of a software system, the software system comprising a plurality of active processes executed in an active processor domain, the method comprising the steps of:

generating an active message having a list of the plurality of active processes that are to receive the active message for processing by the active processor domain;

generating a modified active message by providing an active time indicator associated with the active message for each of the plurality of active processes;

generating a stand-by message for processing in a stand-by processor domain, the stand-by processor domain comprising a plurality of stand-by processes;

generating a modified stand-by message by providing a stand-by time indicator for each of the plurality of stand-by processes in the stand-by domain;

generating a statistical characteristic for the modified active message; and

based on the statistical characteristic, interchanging the stand-by processor domain with the active processor domain.

2. The method of claim 1 further comprising the step of determining a status of the active processor domain in response to the active time indicator.

3. The method of claim 2 wherein a respective active time indicator is associated with each process of the plurality of processes, and wherein the step of determining the status of the active processor domain is responsive to more than one of the active time indicators.

4. The method of claim 1 wherein the active time indicator comprises a time-stamp indicating the time the at least one process completed processing the active message.

5. The method of claim 1 wherein the active time indicator comprises a time-stamp indicating the time elapsed while the at least one process processed the active message.

6. The method of claim 1 wherein the step of determining the statistical characteristic comprises generating a time average of the duration of the at least one process of the plurality of processes for a plurality of active messages.

7. The method of claim 6 wherein the step of determining statistical characteristic comprises generating a standard deviation from the time average.

8. The method of claim 1, further comprising the step of determining a status of the stand-by processor domain in response to the stand-by time indicator.

9. The method of claim 8 wherein a respective stand-by time indicator is associated with each process of the plurality of stand-by processes of the stand-by domain and wherein the step of determining the status of the stand-by processor domain is responsive to at least two of the stand-by time indicators.

10. The method of claim 1, including the further step of forwarding the active message to the active processes on the list, to allow respective active processes to generate the modified active message.

11. The method of claim 1, wherein interchanging the stand-by processor domain with the active processor domain based on the statistical characteristic, includes comparing the statistical characteristic to a predetermined threshold value.

12. The method of claim 1, wherein interchanging the stand-by processor domain with the active processor domain based on the statistical characteristic, includes comparing the statistical characteristic generated for the active processor to the statistical characteristic generated for the stand-by processor.

13. A method of enhancing fault tolerance of a software system, the software system comprising a plurality of active processes executed in an active processor domain, the method comprising the steps of:

generating an active message for processing by the active processor domain;

generating a modified active message by providing an active time indicator associated with the active message for each of the plurality of active processes;

generating a stand-by message for processing in a stand-by processor domain, the stand-by processor domain comprising a plurality of stand-by processes;

generating a modified stand-by message by providing a stand-by time indicator for each of the plurality of stand-by processes in the stand-by domain;

generating a statistical characteristic for the modified active message; and

based on the statistical characteristic, interchanging the stand-by processor domain with the active processor domain;

wherein interchanging the stand-by processor domain with the active processor domain based on the statistical characteristic, includes comparing the statistical characteristic generated for the active processor to the statistical characteristic generated for the stand-by processor.