Abstract:
A technique for automated discovery of relationships between components providing a service and discovery of the relationship of shared components to other services. A discovery engine determines a management address for a component experiencing a problem and retrieves a TCP connection table for the component. It then identifies TCP connections that are either active or that were recently active. For each, the destination address is added to a global connection table. After the TCP connection table has been processed in this manner, the global connection table is traversed and TCP connection tables for each listed destination address are examined recursively. At the conclusion of this recursive process, the management table contains a list of management agents in the distributed system to which the original component had a TCP connection, either directly or indirectly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/588,257, filed Jul. 14, 2004, which is incorporated by reference herein in its entirety. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to data processing systems, and more particularly, to the automatic discovery of relationships between components of distributed networks, systems, and applications. 
   2. Description of Background Art 
   A wide variety of computer-implemented services are available to consumers, manufacturers and others. For example, an investor can buy and sell stocks or other financial instruments over the web; travelers can check in for flights at airport kiosks; products can be configured for shipment; and the like. 
   Often, a user of a computer-implemented service or a computer program itself wishes to perform a task and cannot, because a necessary component is unavailable. For example, the needed component might be already in use and locked, corrupted, or missing altogether. Alternatively, necessary components might be available, but the overall performance of the service is poor. For example, a stock purchasing service might be functional but slow, so that trades guaranteed by the service provider to process in 5 seconds fail to be processed within 5 seconds, thereby violating an agreement between the stock trading service provider and their customer. 
   When service-affecting problems occur, software engineers typically seek to resolve them quickly, and where possible to detect them before they affect users of the service. One conventional method for resolving such problems involves proactively testing the end-to-end availability and performance of the IT system delivering the service. A robot can be used to programmatically test the service while monitoring service performance and availability. For example, products such as Keynote Transaction Perspective by Keynote Systems, Inc., Gomez Performance Network, by Gomez, Inc., and Mercury Business Process Monitor, by Mercury Interactive Corporation test services to determine when service failures and degradation occur. 
   Another method for resolving such problems involves monitoring use of the service to detect service-affecting problems. Solutions such as Timestock CTQ monitor actual users of the service and detect when service-affecting problems exist for these users. Both of these approaches, testing a service, and monitoring a service, along with other approaches, provide awareness of service-affecting performance and availability problems, among other service-affecting problems. 
   When a performance, availability, or other service-affecting problem is detected, an alert can be sent to an operator. An operator may then manually interrogate the individual components of the service to ascertain where a fault exists. Because services may be composed of a large number of components it may be difficult for the operator to identify those components upon which the service depends. 
   Services may depend on the performance and availability of many components, such as network routers and switches and the software executing on them; server hardware and the software executing on them, such as web server software, application server software, and database software; and mainframe computers and software executing on them, among other components. To determine dependencies between service components, conventional methods include application of periodic discovery and mapping techniques. These techniques create a map of dependency relationships periodically, generally on a scheduled basis. Micromuse Netcool for Business Service Management, by Micromuse Inc., and Mercury Application Mapping, by Mercury Interactive Corporation, are examples of products that attempt to map these service dependencies. 
   With the advent of technology such as web services, where relationships between components tend to be ephemeral, mappings can quickly become inaccurate, making it even harder to determine where the cause of a service-affecting problem lies. In addition, services often depend upon components that are shared amongst multiple services. External effects from other services sharing a component may have an effect on the service being tested, monitored, and/or mapped. For example, a service depending upon a certain amount of available bandwidth on a network circuit may be adversely (and temporarily) affected by another service sharing the use of that network circuit. Such interdependencies may not be reflected in a service dependency map, and may be temporary and fleeting. 
   While this approach may eventually resolve the problem, it is manual, time-consuming, and in many cases relies on prior knowledge that has become inaccurate due to frequent changes in the IT infrastructure environment. 
   Accordingly, there is a need for a system and method for automatically discovering relationships between components involved in providing a service and for discovering the relationship of shared components to other services at or near the time of a service-affecting problem. 
   SUMMARY OF THE INVENTION 
   The present invention enables the automatic discovery of relationships between components involved in providing a service and also enables the discovery of the relationship of shared components to other services at or near the time of a service-affecting problem. 
   A system in accordance with the present invention includes a discovery engine; an IP-address-to-management-address table; a management agent table; TCP connection tables and a global connection table. 
   The discovery engine obtains the IP address of a component associated with the identified problem, and using the IP-address-to-management-address table determines a management address for the component. The discovery engine then retrieves a TCP connection table for the component and from the TCP connection table identifies TCP connections that are either active or that were recently active. For each identified connection, the destination address associated with the connection is added to the global connection table. After the TCP connection table has been processed in this manner, the global connection table is traversed. For each row in the global connection table, the management address associated with the indicated destination address is compared to the addresses in the management agent table. If the address is not found in the management table, it is added, and the TCP connection table for the associated component is retrieved and processed as described above. At the conclusion of this recursive process, the management table contains a list of management agents in the distributed system to which the original component had a TCP connection, either directly or indirectly. One use of this list of management agents is to access component identity, configuration, utilization, performance, and state information, among other information, for the service components associated with these management agents using access methods well known to those skilled in the art. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of the overall architecture of an embodiment of the present invention. 
       FIG. 2A  and  FIG. 2B  provide a flowchart illustrating a method of automatic discovery of relationships in accordance with an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is a block diagram illustrating a system for discovering component relationships in accordance with an embodiment of the present invention. System  100  includes a management address table  102 , a TCP connection table  104 , a global connection table  106 , a discovery engine  108 , and an IP-address-to-management-address table  110 . Each is described further below. 
   Referring to  FIG. 2A , system  100  receives  202  a notification that a problem exists with a service. As described above, a problem includes the unavailability of a required component, a performance problem with the service being provided, or more generally a failure of the service to meet a specified metric or other standard of service utility and/or quality. In one embodiment, the existence of a problem can be detected automatically as described for example in U.S. Patent Publication 2003-0191989 A1, incorporated by reference herein in its entirety. In an alternative embodiment, the existence of a problem can be discovered through testing as described above, or through other conventional means. 
   The notification of a problem preferably includes the IP address of a machine associated with the problem. This IP address is known as the origination address. Discovery engine  108  resolves  204  the origination address to an IP management address by consulting IP-address-to-management-address table  110 . For example, the origination address may be the address of a web server responding to a client request and may be resolved through lookup in table  110 . IP-address-to-management-address table  110  may be preconfigured with IP address-to-management-address mappings specified by user configuration or populated using automated discovery methods. Discovery engine  108  then initializes  206  management agent table  102 , and adds  208  the management address to the table  102 . 
   Once discovery engine  108  obtains the management address of the originating system, it retrieves  210  the TCP connection table  104  from the origination system via the specified management interface. The TCP connection table in one embodiment is in a format as described in IETF RFC 1213, for example, and may be retrieved by access methods in accordance with the SNMP standard, among other access methods. Additional agent access parameters necessary to access this information may be provided by default, for example by trying the default SNMP community string values of “public” and/or “private”, or by using pre-defined values specified by user configuration or automated discovery. 
   Next, discovery engine  108  initializes  212  global connection table  106  for use as described below, and begins to traverse the TCP connection table  104 . Rows in the TCP connection table  104  preferably conform to IETF RFC 1213, though other configurations may be used in alternative embodiments. If the connection state is  214  not one indicating that a connection is open or was recently open, for example ESTABLISHED, FIN_WAIT — 1, FIN_WAIT — 2, CLOSE_WAIT, CLOSING, LAST_ACK, or TIME-WAIT, then the row is discarded  216 . Otherwise, the TCP connection source IP address is compared to the origination IP address and if  218  they are the same then the row is discarded  216 . If a row is not discarded for either reason, it is added  220  to global connection table  106 . If  222  more rows remain in the TCP connection table  104 , the process is repeated until the rows in the table are exhausted. At such time, management agent table  102  includes the management IP address of the origination system, and global connection table  106  includes a list of the connections for the origination system that are currently established or that have been recently established for all interfaces except for the interface specified as the origination interface. 
   Next, and referring now to  FIG. 2B , discovery engine  108  begins to process the rows of global connection table  106 . Although the table  106  is preferably traversed only once, rows may be appended to the table  106  as part of the discovery process as described below. 
   Discovery engine  108  begins by retrieving  224  a first row from global connection table  106  and setting  226  the origination interface to the destination address noted in the retrieved row. Next, discovery engine  108  resolves  228  the management address for this origination address, preferably by looking it up in IP-address-to-management-address table  110 . In one embodiment, if the management address cannot be resolved this occurrence is noted and the row discarded. Next, the resolved management address is compared against entries in management table  102 . If  230  the address is found in the management table the row is preferably discarded  232 . If the management address is not found in the management table  102 , the management address is added  234  to the management table  102 . Discovery engine  108  then retrieves  236  the TCP connection table  104  for this management address and examines  238  the TCP connection table as described above with respects to steps  214 - 222 . Upon completion of this processing, the global connection table  106  is examined, and if  240  all rows have been processed the method is complete, otherwise the process loops until all rows have been processed. 
   Upon completion of this process the management table  102  contains a list of the management agents on the computer systems for which the origination server had a TCP connection, either directly or indirectly. 
   The present invention has been described in particular detail with respect to a limited number of embodiments. Those of skill in the art will appreciate that the invention may additionally be practiced in other embodiments. For example, the functionality of the discovery engine  108  can be provided in other embodiments by other modules. 
   Within this written description, the particular naming of the components, capitalization of terms, the attributes, data structures, or any other programming or structural aspect is not mandatory or significant, and the mechanisms that implement the invention or its features may have different names, formats, or protocols. Further, the system may be implemented via a combination of hardware and software, as described, or entirely in hardware elements. Also, the particular division of functionality between the various system components described herein is merely exemplary, and not mandatory; functions performed by a single system component may instead be performed by multiple components, and functions performed by multiple components may instead performed by a single component. For example, the particular functions of discovery engine  108 , global connection table  106  and so forth may be provided in many or one module. 
   Some portions of the above description present the feature of the present invention in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are the means used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art. These operations, while described functionally or logically, are understood to be implemented by computer programs. Furthermore; it has also proven convenient at times, to refer to these arrangements of operations as modules or code devices, without loss of generality. 
   It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. 
   Certain aspects of the present invention include process steps and instructions described herein in the form of an algorithm. It should be noted that the process steps and instructions of the present invention could be embodied in software, firmware or hardware, and when embodied in software, could be downloaded to reside on and be operated from different platforms used by real time network operating systems. 
   The present invention also relates to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, magnetic or optical cards, application specific integrated circuits (ASICs), or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. Furthermore, the computers referred to in the specification may include a single processor or may be architectures employing multiple processor designs for increased computing capability. 
   The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may also be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description above. In addition, the present invention is not described with reference to any particular programming language. It is appreciated that a variety of programming languages may be used to implement the teachings of the present invention as described herein, and any references to specific languages are provided for disclosure of enablement and best mode of the present invention. 
   Finally, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention.