System and method for isolating faults in a network

• US 6,990,609 B2
• Filed: 06/13/2002
• Issued: 01/24/2006
• Est. Priority Date: 06/12/2001
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Wiley, Stephen A., Cadieux, Christian, Schell, John
• Primary Examiner(s): Iqbal, Nadeem
• Application Number:
  US10/172,302
• Publication Number:
  US 20030233598A1
• Time in Patent Office: 1,321 Days
• Field of Search: 714/25, 714/27, 714/39, 714/43, 714/47, 714/49, 714/56, 714/32, 709/220, 709/221, 709/224, 709/223, 710/15, 710/17, 370/221, 370/223, 370/242
• US Class Current: 714/25
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/079 Root cause analysis, i.e. error or fault diagnosis in a hardware test environment G06F11/22; in a software test environment G06F11/36
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/0677 Localisation of faults

Abstract

A fault isolation system in a network is disclosed, particularly suited for use in a unidirectional fibre channel arbitrated loop. Information relating to read and write errors occurring on the loop is stored, and fault regions are located by determining areas on the loop downstream of write errors and upstream of read errors. The system may be extended to networks with bidirectional communications by storing directionality information with the detected errors. Command and response error information is not needed to deterministically locate the fault regions. When a given fault region is identified, loop and device diagnostics are executed for that region of the loop to specifically identify the failed components.

Claims

1. An error isolation system adapted for use in a computer network in communication with a storage device configured to store error information relating to at least one detected error that occurs in the network, the system having a plurality of program modules configured to execute on at least one processor, the program modules including:

an error identification module configured to determine whether the detected error is a write error or a read error; and

a failure region detection module configured to identify a failure region on the network, the failure region being between a first location on the network at which a write error is detected and a second location on the network at which a read error is detected.

2. The system of claim 1, wherein:

the network includes at least one unidirectional loop; and

the failure region detection module is configured to isolate errors occurring within the unidirectional loop.

3. The system of claim 2, wherein the unidirectional loop comprises a fibre channel arbitrated loop.

4. The system of claim 2, wherein the failure region detection module is further configured to identify the failure region as being within an intersection of at least two detected errors.

5. The system of claim 4, wherein the two detected errors include a read error and a write error.

6. The system of claim 2, wherein the failure region detection module is further configured to identify the failure region as being downstream of a first read error and upstream of a first write error.

7. The system of claim 1, wherein:

the network includes at least one bidirectional loop;

the failure region detection module is configured to isolate errors occurring within the bidirectional loop; and

the error identification module is configured to identify, for each detected error, a directionality on the bidirectional loop for that detected error.

8. The system of claim 7, wherein the failure region detection module is further configured to identify the failure region as being within an intersection of at least two detected errors.

9. The system of claim 8, wherein:

the failure region detection module is further configured to identify the failure region as being downstream of a first read error and upstream of a first write error;

wherein the directionality of the first read error is the same as the directionality of the first write error.

10. The system of claim 8, wherein:

the failure region detection module is further configured to identify the failure region as being downstream, relative to a first directionality, of a first read error and downstream, relative to a second directionality, of a second read error.

11. The system of claim 8, wherein:

the failure region detection module is further configured to identify the failure region as being upstream, relative to a first directionality, of a first write error and upstream, relative to a second directionality, of a second write error.

12. A method for locating a fault region in a network in communication with a storage device configured to store error information relating to detected errors that occurs in the network, the method including the steps of:

determining whether each of a plurality of detected errors is a read error or a write error; and

identifying a failure region on the network between a first location on the network where a first read error is detected and a second location on the network where a first write error is detected.

13. The method of claim 12, wherein the identifying step includes identifying the failure region as being within a unidirectional portion of the network.

14. The method of claim 12, wherein the identifying step includes identifying the failure region as begin within a fibre channel arbitrated loop.

15. The method of claim 12, wherein the identifying step includes identifying the failure region as being downstream of a detected read error and upstream of a detected write error.

16. The method of claim 12, wherein the identifying step includes identifying the failure region as being within a bidirectional portion of the network.

17. The method of claim 16, wherein the identifying step includes determining an associated directionality for each of the plurality of detected errors.

18. A computer program product stored on a computer-usable medium, comprising a computer-readable program configured to cause a computer to control execution of an application to determine a fault region associated with a plurality of detected errors in a network, the computer-readable program including:

an error identification module configured to determine whether each of the plurality of detected errors is a write error or a read error; and

a failure region detection module configured to identify a failure region on the network, the failure region being between a first location on the network at which a write error is detected and a second location on the network at which a read error is detected.

19. The computer program product of claim 18, wherein the failure region detection module is configured to identify the failure region as being upstream of a first detected write error and downstream of a first detected read error.

20. A computer network, including:

a host including a processor and a host bus adapter;

a loop coupled to the host bus adapter and configured to carry packets from the host bus adapter to at least one device on the loop and from the device to the host bus adapter;

first logic coupled to the host and configured to detect a plurality of errors in the packets on the loop, the errors including at least one detected read error and one detected write error; and

second logic coupled to the host and configured to locate a failure region on the loop downstream of the detected read error and upstream of the detected write error.