APPARATUS AND METHOD TO MINIMIZE PERFORMANCE DEGRADATION DURING COMMUNICATION PATH FAILURE IN A DATA PROCESSING SYSTEM

• US 20090319822A1
• Filed: 06/18/2008
• Published: 12/24/2009
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Hathorn, Roger Gregory, Holley, Bret Wayne, Coronado, Juan Alonso, Valencia, Clarisa
• Granted Patent: US 8,108,732 B2
• Time in Patent Office: Days
• US Class Current: 714/3
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: G06F 11/076 by exceeding a count or rate limit, e.g. word- or bit count limit
• CPC Class Codes: G06F 11/32 with visual or acoustical indication of the functioning of the machine
• CPC Class Codes: H04L 43/0811 by checking connectivity
• CPC Class Codes: H04L 43/0847 Transmission error
• CPC Class Codes: H04L 43/16 Threshold monitoring
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A method to minimize performance degradation during communication path failure in a data processing system, comprising a host computer, a storage controller, and a plurality of physical communication paths in communication with the host computer and the storage controller, where the method establishes a. threshold communication path error rate, and determines an (i)th actual communication path error rate for an (i)th physical communication path, wherein that (i)th communication path is one of the plurality of physical communication paths. If the (i)th actual communication path error rate is greater than the threshold communication path error rate, the method discontinues use of the (i)th physical communication path.

Claims

1. A method to minimize performance degradation during communication path failure in a data processing system, comprising:

supplying a host computer, a storage controller, and a plurality of physical communication paths in communication with said host computer and said storage controller;

establishing a threshold communication path error rate;

determining an (i)th actual communication pat error rate for an (i)th physical communication path, wherein said (i)th physical communication path is one of said plurality of physical communication paths in communication with said host computer and said storage controller;

operative if said (i)th actual communication pat error rate is greater than said threshold communication path error rate, discontinuing use of said (i)th physical communication path.

2. The method of claim 1, wherein said supplying step further comprises supplying a host computer comprising a communication path manager, said method further comprising:

determining by said communication pat manager said (i)th actual first communication path error rate;

operative if said (i)th actual first communication pat error rate is greater than said threshold communication path error rate, providing an instruction by said communication path manager to said storage controller using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said host computer communication path manager any I/O received from said storage controller using said (i)th physical communication path.

3. The method of claim 2, wherein said supplying step further comprises supplying a visual display device in communication with said host computer, said method further comprising visually displaying on said visual display device an error message reading that an (i)th actual communication path error rate is greater than said threshold communication path error rate.

4. The method of claim 3, wherein said supplying step further comprises supplying a host computer comprising a communication path error log, said method further comprising:

making a communication path error log entry comprising the date and time, and indicating that an (i)th actual communication path error rate is greater than said threshold communication path error rate.

5. The method of claim 1, wherein said supplying step flirter comprises supplying a storage controller comprising a communication management function, said method further comprising:

determining by said communication management function said (i)th actual communication path error rate;

providing an instruction by said communication management function to said host computer using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said storage controller communication management function any I/O received from said host computer using said (i)th physical communication path.

6. The method of claim 5, wherein said supplying step her comprises supplying a service center in communication with said storage controller, wherein said service center comprises a visual display device, said method finer comprising displaying on said visual display device an error message reading that an (i)th actual communication path error rate is greater than said threshold communication path error rate.

7. The method of claim 6, wherein said supplying step further comprises supplying a storage controller comprising a communication path error log, said method further comprising:

making a communication path error log entry comprising the date and time, and indicating that an (i)th actual communication path error rate is greater than said threshold communication path error rate; and

providing said log entry to said service center.

8. The method of claim 1, wherein said supplying step further comprises supplying a data storage system comprising:

a first cluster and a second cluster, wherein said first cluster and said second cluster are disposed in the same housing;

wherein said first cluster comprises a first storage controller assembly comprising a first processor and a first communication management function, and wherein said second cluster comprises a second storage controller assembly comprising a second processor and a second communication management function, and wherein said data storage system is in communication with said host computer via said plurality of physical communication paths;

wherein said method comprises;

determining by said first communication management function said (i)th actual communication path error rate;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, providing an instruction by said first communication management function to said host computer using a (j)th physical communication path to discontinue use of said (i)th physical communication pat, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said first storage controller assembly any I/O received from said host computer using said (i)th physical communication path.

9. The method of claim 8, further comprising:

determining by said second communication management function said (i)th actual communication path error rate;

operative if said (i)th actual first communication path error rate is greater than said threshold communication pat error rate, providing an instruction by said second communication management function to said host computer using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said second storage controller assembly any I/O received from said host computer using said (i)th physical communication path.

10. The method of claim 8, wherein said supplying step further comprises supplying a data storage system comprising a communication pat error log and a service center in communication with said data storage system, wherein said service center comprises a visual display device, said method further comprising:

displaying on said visual display device an error message reading that an (i)th actual communication path error rate is greater man said threshold communication path error rate;

making a communication path error log entry comprising the date and time, and indicating that an (i)th actual communication path error rate is greater than said threshold communication path error rate; and

providing said log entry to said ice center.

11. A computing device comprising a computer readable medium comprising computer readable program code disposed therein to minimize performance degradation during communication path failure in a data processing system, wherein said computing device is in communication with a storage controller via a plurality of communication paths, the computer readable program code comprising a series of computer readable program steps to effect:

retrieving a predetermined threshold communication path error rate;

determining an (i)th actual communication path error rate for an (i)th physical communication path, wherein said (i)th physical communication path is one of said plurality of communication paths;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, discontinuing use of said (i)th physical communication path.

12. The computing device of claim 11, wherein said computing device comprises a communication path manager, said computer readable program code further comprising a series of computer readable program steps to effect:

determining by said communication path manager said (i)th actual first communication pat error rate;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, providing an instruction by said communication path manager to said storage controller using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said communication path manager any I/O received from said storage controller using said (i)th physical communication path.

13. The computing device of claim 12, wherein said computing device farther comprises a visual display device and a communication path error log, said computer readable program code further comprising a series of computer readable program steps to effect:

visually displaying on said visual display device an error message reading that an (i)th actual communication path error rate is greater than said threshold communication path error rate; and

making a communication path error log entry comprising the date, time, and indicating that (i)th actual communication path error rate is greater than said threshold communication path error rate.

14. A storage controller comprising a computer readable medium comprising computer readable program code disposed therein to minimize performance degradation during communication path failure in a data processing system, wherein said storage controller is in communication with a computing device via a plurality of physical communication paths, the computer readable program code comprising a series of computer readable program steps to effect:

retrieving a pre-determined threshold communication pat error rate;

determining an (i)th actual communication path error rate for an (i)th physical communication pat, wherein said (i)th physical communication path is one of said plurality of communication pats;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, discontinuing use of said (i)th physical communication path.

15. The storage controller of claim 14, further comprising a communication management function, said computer readable program code further comprising a series of computer readable program steps to effect:

determining by said communication management function said (i)th actual communication path error rate;

providing an instruction by said communication management function to said computing device using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said communication management function any I/O received from said computing device using said (i)th physical communication path.

16. The storage controller of claim of claim 15, wherein said storage controller is in communication with a service center comprising a visual display device, and wherein said storage controller further comprises a communication path error log, said computer readable program code further comprising a series of computer readable program steps to effect:

visually displaying on said visual display device an error message reading that an (i)th actual communication path error rate is greater than said threshold communication path error rate;

making a communication path error log entry comprising the date, time, and indicating that (i)th actual communication path error rate is greater than said threshold communication path error rate; and

providing said log entry to said service center.

17. A data storage system comprising a computer readable medium comprising computer readable program code disposed therein to minimize performance degradation during communication path failure in a data processing system, wherein said data storage system comprises a first cluster and a second cluster, wherein said first cluster and said second cluster are disposed in the same housing, wherein said first cluster comprises a first storage controller assembly comprising a first processor and a first communication management function, and wherein said second cluster comprises a second storage controller assembly comprising a second processor and a second communication management function, and wherein said data storage system is in communication with a computing device via a plurality of physical communication paths, the computer readable program code comprising a series of computer readable program steps to effect:

retrieving a pre-determined threshold communication path error rate;

determining an (i)th actual communication path error rate for an (i)th physical communication path, wherein said (i)th physical communication path is one of said plurality of communication paths;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, discontinuing use of said (i)th physical communication path

18. The data storage system of claim 17, said computer readable program code further comprising a series of computer readable program steps to effect:

determining by said first communication management function said (i)th actual communication path error rate;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, providing an instruction by said first communication management function to said host computer using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said (j)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said first storage controller assembly any I/O received from said host computer using said (i)th physical communication path.

19. The data storage system of claim 18, the computer readable program code comprising a series of computer readable program steps to effect:

determining by said second communication management function said (i)th actual communication path error rate;

operative if said (i)th actual first communication path error rate is greater than said threshold communication path error rate, providing an instruction by said second communication management function to said computing device using a (j)th physical communication path to discontinue use of said (i)th physical communication path, wherein said O)th physical communication path is one of said plurality of communication paths in communication with said host computer and said storage controller, and wherein said (i)th physical communication path differs from said (j)th physical communication path;

rejecting by said second storage controller assembly any I/O received from said computing device using said (i)th physical communication path.

20. The data storage system of claim 19, wherein said data storage system is in communication with a service center comprising a visual display device, and wherein said data storage system farther comprises a communication path error log, said computer readable program code further comprising a series of computer readable program steps to effect:

visually displaying on said visual display device an error message reading that an (i)th actual communication path error rate is greater than said threshold communication path error rate;

making a communication path error log entry comprising the date, time, and indicating that (i)th actual communication path error rate is greater than said threshold communication path error rate; and

providing said log entry to said service center.