Root-cause analysis of network performance problems

• US 20060215564A1
• Filed: 03/23/2005
• Published: 09/28/2006
• Est. Priority Date: 03/23/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Breitgand, David, Shehory, Onn, Yerushalmi, Elena, Henis, Ealan, Ladan-Mozes, Edya
• Granted Patent: US 7,489,639 B2
• Time in Patent Office: Days
• US Class Current: 370/241
• CPC Class Codes: H04L 41/0631 using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 41/18 Delegation of network management function, e.g. customer network management [CNM]
• CPC Class Codes: H04L 43/0811 by checking connectivity

Abstract

A method for diagnosing network performance problems includes providing a graph representing a topology of a network including first nodes that are classified as providers of a resource, second nodes that are classified as consumers of the resource, and third nodes that are classified as mediators intervening between the providers and the consumers. Responsively to a report of a performance problem encountered by a given consumer in the network, at least one input/output (I/O) path is traced through the graph connecting the given consumer to one or more of the providers. One or more problematic nodes are identified along the at least one I/O path as possible causes of the performance problem.

Claims

1. A method for diagnosing network performance problems, the method comprising:

providing a graph representing a topology of a network comprising first nodes that are classified as providers of a resource, second nodes that are classified as consumers of the resource, and third nodes that are classified as mediators intervening between the providers and the consumers;

receiving a report of a performance problem encountered by a given consumer in the network;

responsively to the report, tracing at least one input/output (I/O) path through the graph connecting the given consumer to one or more of the providers; and

identifying one or more problematic nodes along the at least one I/O path as possible causes of the performance problem.

2. The method according to claim 1, wherein providing the graph comprises identifying physical and logical links between the nodes, and wherein tracing the at least one I/O path comprises building the at least one I/O path in accordance with the logical links.

3. The method according to claim 2, wherein identifying the logical links comprises providing a logical mapping between the nodes, and wherein building the at least one I/O path comprises eliminating from the path the physical links that do not correspond to the logical mapping.

4. The method according to claim 1, wherein providing the graph comprises grouping a plurality of the nodes together into a super-node having an internal node structure, and wherein tracing the at least one I/O path comprises tracing the at least one I/O path through the super-node without reference to the internal node structure.

5. The method according to claim 1, wherein the network comprises a storage area network (SAN), and wherein the resource comprises at least one of a storage capacity and a bandwidth.

6. The method according to claim 5, wherein the first nodes comprise storage servers having logical volumes associated therewith, and wherein receiving the report comprises receiving an indication of at least one of a capacity problem and a throughput problem in one of the logical volumes.

7. The method according to claim 5, wherein the first nodes comprise storage servers having logical volumes associated therewith, and wherein the second nodes comprise storage devices having logical units associated therewith, and wherein tracing the at least one I/O path comprises extending the at least one I/O path from one of the logical volumes to one or more of the logical units.

8. The method according to claim 1, wherein tracing the at least one I/O path comprises building a directed acyclic graph (DAG) within the topology of the network from the given consumer to the providers that are coupled by the topology to provide the resource to the given consumer.

9. The method according to claim 1, wherein identifying the one or more problematic nodes comprises monitoring performance metrics of the nodes in the network, and identifying a given node as problematic if one or more of the performance metrics of the given node are outside a predefined bound.

10. The method according to claim 1, and comprising:

tracing a further I/O path through the graph connecting another consumer to the providers and crossing the at least one I/O path at one of the problematic nodes; and

identifying one or more further problematic nodes along the further I/O path as a possible cause of the performance problem.

11. The method according to claim 10, wherein tracing the further I/O path comprises initiating the tracing of the further I/O path upon determining that the one or more problematic nodes identified along the at least one I/O path are not the causes of the performance problem.

12. Apparatus for diagnosing network performance problems, the apparatus comprising:

a memory, which is arranged to store a graph representing a topology of a network comprising first nodes that are classified as providers of a resource, second nodes that are classified as consumers of the resource, and third nodes that are classified as mediators intervening between the providers and the consumers; and

a processor, which is arranged to receive a report of a performance problem encountered by a given consumer in the network, and to trace, responsively to the report, at least one input/output (I/O) path through the graph connecting the given consumer to one or more of the providers and to identify one or more problematic nodes along the at least one I/O path as possible causes of the performance problem.

13. The apparatus according to claim 12, wherein the graph identifies physical and logical links between the nodes, and wherein the processor is arranged to build the at least one I/O path in accordance with the logical links.

14. The apparatus according to claim 12, wherein the network comprises a storage area network (SAN), and wherein the resource comprises at least one of a storage capacity and a bandwidth.

15. The apparatus according to claim 14, wherein the first nodes comprise storage servers having logical volumes associated therewith, and wherein the second nodes comprise storage devices having logical units associated therewith, and wherein the processor is arranged to trace the at least one I/O path from one of the logical volumes to one or more of the logical units.

16. The apparatus according to claim 12, wherein the processor is arranged to trace the at least one I/O path by building a directed acyclic graph (DAG) within the topology of the network from the given consumer to the providers that are coupled by the topology to provide the resource to the given consumer.

17. A computer software product for diagnosing network performance problems, the product comprising a computer-readable medium in which program instructions are stored, which instructions, when read by a computer, cause the computer to provide a graph representing a topology of a network comprising first nodes that are classified as providers of a resource, second nodes that are classified as consumers of the resource, and third nodes that are classified as mediators intervening between the providers and the consumers, and further cause the computer, upon receiving a report of a performance problem encountered by a given consumer in the network, to trace, responsively to the report, at least one input/output (I/O) path through the graph connecting the given consumer to one or more of the providers and to identify one or more problematic nodes along the at least one I/O path as possible causes of the performance problem.

18. The product according to claim 17, wherein the graph identifies physical and logical links between the nodes, and wherein the instructions cause the computer to build the at least one I/O path in accordance with the logical links.

19. The product according to claim 17, wherein the network comprises a storage area network (SAN), and wherein the resource comprises at least one of a storage capacity and a bandwidth.

20. The product according to claim 19, wherein the first nodes comprise storage servers having logical volumes associated therewith, and wherein the second nodes comprise storage devices having logical units associated therewith, and wherein the instructions cause the computer to trace the at least one I/O path from one of the logical volumes to one or more of the logical units.