Abstract:
A method is provided for assigning weights to configuration items (CIs) in a configurable managed system, wherein respective weights are derived from information contained in an associated configuration management database. The information could include without limitation the relationships that a configuration item (CI) has with other CIs and the number of reads and writes that are made between the CI and other CIs. A Change Manager in the configurable system makes changes affecting CIs, wherein different types of changes require different levels of confidence in the integrity of data in the CMDB. Accordingly, the weights of respective CIs are used to provide a confidence level regarding the accuracy of CMDB data, pertinent to a proposed change. The confidence level is then used by the Change Manager in deciding whether or not to make the change. One embodiment comprises acquiring information from the CMDB pertaining to CIs that would be affected by a particular change, and processing the acquired information to compute a confidence level indicating the probability that the acquired information is correct. The particular change is then allowed only if the confidence level is no less than a pre-specified minimum value.

Description:
This application is a continuation of application Ser. No. 11/627,398, filed Jan. 26, 2007, status abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention disclosed and claimed herein generally pertains to a method for providing assistance in decision making in a configurable managed environment or system, that includes a configuration management database (CMDB) and configuration items (CI). More particularly, the invention pertains to a method of the above type for providing assistance in determining whether or not to make a change in the system that would affect one or more of the CIs. Even more particularly, the invention pertains to a method of the above type for computing a confidence level representing the probability that information provided by the CMDB is accurate. The Change Manager also gets the information on the impact of the proposed change. 
     2. Description of the Related Art 
     Configuration management is a critical process responsible for identifying, controlling and tracking all versions of hardware, software, documentation, and other inanimate components of a configurable managed environment, such as an Information Technology organization. The goal of configuration management is to ensure that only authorized components, referred to as configuration items (CIs), are used in the configurable managed environment, and that all changes to CIs are recorded and tracked throughout the life cycle of the component. The configuration management process includes performing tasks such as identifying CIs and their relationships, and adding them to the CMDB. The CMDB is a database that contains all relevant details for each CI, such as relationships between CIs, state or status, and historical information. Some examples of CIs are Computer System, Application Server etc. The data and relationships in the CMDB are used by a system manager, referred to as a Change Manager, for making changes in the configurable managed environment or system, wherein the changes generally will affect one or more of the configuration items. A definition of the Change Manager, provided by the Information Technology Infrastructure Library (ITIL), is set forth hereinafter. 
     The CMDB nominally contains the latest information of the above type for all CIs, such as the states and relationships thereof. Information about respective CIs is referred to herein as configuration item data (CID). In a configurable managed environment, as events occur that change the states or relationships of respective CIs, the CMDB must be synchronized accordingly. That is, the CMDB must be updated, so that the data contained therein will represent the new CID, that is, new realities of the CIs. However, in a configurable managed environment of the above type, multiple point products are commonly present that create and change relationships among the CIs. Such point products are described hereinafter in further detail, and may, for example, comprise devices such as the Tivoli Configuration Manager (TCM), a product of International Business Machines Corporation. The multiple point products are also commonly used to report changed conditions of the CIs to the CMDB. 
     Because the CMDB receives CI change data from different point products, it can happen that data received from the different point products, in regard to the same CIs, will be in conflict. Moreover, delays of varying lengths may occur between actual changes of CI conditions, and the reporting of such changed conditions to the CMDB. As a result, a typical CMDB that is being populated with data from multiple point product sources cannot be kept in synchronization with the actual real world condition of all CIs, since it is virtually impossible to keep CID synchronization up to date. 
     In a configurable managed environment or system, Change Managers make systems management decisions based on the state and relationships of the CIs, as shown by information in the CMDB. Some changes to the environment are trivial, while other changes can have serious consequences. For example, a change such as disabling a monitoring service on a hardware CI will usually be of low impact, while deleting a software component from a server for a change management operation can have serious consequences. However, as discussed above, CMDB information available to the Change Manager is likely to contain inaccuracies, even though such information is to be used as the basis for making changes. Accordingly, it would be desirable to provide the Change Manager with a tool that could serve as an aid in determining whether or not to make certain changes that affect CIs. The tool would take into account both the possibility of inaccurate CMDB information, and the comparative impact of the proposed change and provide information on the probability of a given change being successful or a failure. 
     SUMMARY OF THE INVENTION 
     In association with a CMDB containing information that relates to configuration items (CIs) in a configurable managed system, wherein a change station is provided to make respective changes, a method is provided for determining whether to allow a particular change that would affect at least one of the CIs. The method comprises the steps of acquiring information from the CMDB pertaining to CIs that would be affected by the particular change, and processing the acquired information to compute a confidence level indicating the probability that the acquired information is correct. A particular change is then allowed to be made in the configurable system only if the confidence level is no less than a pre-specified minimum value. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a schematic diagram showing a configurable managed system in which an embodiment of the invention may be carried out. 
         FIG. 2  is a block diagram showing a computer or data processing system for implementing a change station that may be used in the system of  FIG. 1 . 
         FIG. 3  is a flow chart showing respective steps for an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 1 , there is shown a configurable managed system or environment  100  that includes a number of interrelated configuration items (CIs). Well known types of CIs include desktop computers, servers and computer clients, which are exemplified in  FIG. 1  by servers  102  and  104 , and by client  106 . While not shown, the hardware CIs of system  100  may contain operating systems, application programs and other software components that are also CIs. Respective CIs of configurable system  100  can be selectively connected to one another by means of a network  108 , which may, for example, comprise the Internet or a LAN. 
     Referring further to  FIG. 1 , there is shown system  100  provided with a CMDB  112  and point products  114  and  116 . The point products are components that monitor or provide management services for the CIs of system  100 , and furnish data concerning respective CIs to CMDB  108 . Thus, CID information pertaining to CIs, wherein the CIs include hardware, software, and monitoring applications, is stored in CMDB  108  by multiple point product sources, exemplified in  FIG. 1  by point products  114  and  116 . The CID information includes relationships between the CIs. Each of the point products may comprise, for example, a Tivoli Configuration Manager (TCM) as described above, or a Tivoli Provisioning Manager or IBM Tivoli Monitor. These are each well known products and systems made available by the International Business Machines Corporation. Alternatively, such products could include a BMC protocol or a Microsoft SMS. 
     Since information is supplied to CMDB  112  from multiple product point sources, it frequently happens that two or more sources send information to the CMDB that all pertains to the same CI. Also, if the CI includes a number of different configurable elements, information sent to the CMDB for the CI may include data representing the value or state of each element. For example, if the CI comprises a computer component having a hard drive, data stored in the CMDB for the CI could include a value indicating the hard drive storage capacity. 
       FIG. 1  further shows a computer work station, comprising a change station  110 , for use by a Change Manager, or another administrator or user associated with configurable managed system  100 . In a system of this type, for example a new healthcare system, it is typically necessary to make sure that there are sufficient hardware and software resources, sufficient power and training, and sufficient other types of resources. System changes to some of the resources can impact other resources as well. Accordingly, a Change Advisory Board (CAB) may be established to oversee changes, and a Change Manager, or another administrator or user, is tasked with executing changes. 
     Change station  110  is operable by the Change Manager or other user to establish and change relationships between respective CIs. Accordingly, change station  110  is provided with a user interface as further indicated at  FIG. 2 . For example, change station  110  could be operated by the Change Manager or other user to install an application into one of the servers  102  or  104 , or to disconnect a point product monitor from another CI. Change station  110  may also be operated to carry out an embodiment of the invention, as described herein. 
     Referring to  FIG. 2 , there is shown a block diagram of a generalized data processing system  200  which may be used to implement change station  110 . Data processing system  200  exemplifies a computer, in which code or instructions for implementing the processes of the present invention may be located. Data processing system  200  usefully employs a peripheral component interconnect (PCI) local bus architecture, although other bus architectures may alternatively be used.  FIG. 2  shows a processor  202  and main memory  204  connected to a PCI local bus  206  through a Host/PCI bridge  208 . PCI bridge  208  also may include an integrated memory controller and cache memory for processor  202 . 
     Referring further to  FIG. 2 , there is shown a local area network (LAN) adapter  212 , a small computer system interface (SCSI) host bus adapter  210 , and an expansion bus interface  214  respectively connected to PCI local bus  206  by direct component connection. SCSI host bus adapter  210  provides a connection for hard disk drive  218 , and also for CD-ROM drive  220 . Expansion bus interface  214  provides a connection for user interface elements such as a keyboard and mouse adapter  222 , modem  224 , and additional memory  226 . 
     An operating system runs on processor  202  and is used to coordinate and provide control of various components within data processing system  200  shown in  FIG. 2 . The operating system may be a commercially available operating system such as Windows XP, which is available from Microsoft Corporation. Instructions for the operating system and for applications or programs are located on storage devices, such as hard disk drive  220 , and may be loaded into main memory  204  for execution by processor  202 . 
     The CI data reported from multiple products is in a standard form, and the CI information from all the products is consolidated into a single CI data item. As discussed above, it is likely that at any given time, at least some of the data stored in the CMDB for a particular CI will not be accurate. This is due in part to delay between an actual change in the condition or state of a CI, and the reporting of the change to the CMDB. Inaccuracies can also result from conflicts in information pertaining to a CI that is reported to the CMDB by different point products. Thus, when the Change Manager is tasked with making a proposed change to the configurable managed system  100 , wherein the change will affect one or more CIs, change station  110  can be used to implement a procedure in accordance with the embodiment of the invention, as illustrated by  FIG. 3 . This procedure will reduce the possibility of adverse consequences that are caused by making a change based on inaccurate CI information in the CMDB. 
     Referring to  FIG. 3 , there is shown an initial step  302  of identifying each of the CIs that are affected by a proposed change. Such identification is performed by the CMDB, which is a repository for information pertaining to all CIs of a system, including the states and relationships thereof. When the CMDB receives data indicating a proposed change, it will be able to determine, from the relationships existing therein, whether a particular CI will be affected by the changes. If so, the CMDB identifies the particular CI. 
     At step  304 , information stored in the CMDB for one of the identified CIs is selected or acquired from the CMDB, wherein the acquired information is relevant to the proposed change. For example, the proposed change could require loading an application into the hard drive of a particular CI, so that it would be necessary to know the available capacity of the hard drive. While the CMDB might contain reports listing information for a number of elements of the particular CI, only the value of hard drive capacity would be pertinent to the proposed change. Step  304  would be carried out for all of the CIs identified at step  302 . 
     It will be appreciated that in some situations a particular source of information will have such authority, relative to competing sources, that the conflicting data from the other competing sources will not be considered. For example, Service Advertising Protocol (SAP) is a service for managing server assets in a system. When a server is first brought into the system, SAP makes a record of the server model and serial number, and of the operating system placed therein. A year later, a point product conducts a scan and indicates that a different operating system is in the server. The SAP is an authoritative system, but its information can be out of date, if the operating system was changed but the SAP was not informed of the change. On the other hand, the point product can perform a scan to correctly identify the operating system, at the time such information is requested. Accordingly, the point product data will simply be accepted over the data from SAP. 
     As a further example for illustrating the embodiment of  FIG. 3 , the hard drive capacity of the particular CI is stated to be 200 GB in three reports sent to the CMDB, but is stated to be 100 GB in one other report. In view of this discrepancy, it becomes necessary to assign a confidence level, or weight, to the information pertaining to this element of the particular CI, as shown by step  306  of  FIG. 3 . With three reports indicating the 200 GB hard drive value against only one report for the 100 GB value, a comparatively high confidence level would be assigned to the 200 GB value. However, if all the reports indicated very different values from one another, the confidence level for this configurable element would be relatively low. CMDB reports typically are stored in a log file or in a data warehouse. Decisions about respective reports are revisited when new information becomes available. 
     More generally, where there are discrepancies or disagreements between multiple reports in the CMDB for a CI or CI element, weights are assigned to the CI based on one or more criteria. These criteria can include the number of times a CI has been read by other CIs, the number of times a CI has been written to or updated by other CIs, the number of relationships that a CI has with other CIs, as shown by information in the CMDB, and how recently a CI was last accessed or updated. 
     Moreover, if one report for a CI element is several years old and another report is very recent, the more recent report will be given significantly higher weight. Generally, a weight can be determined on the basis of a known update or synchronization by a point product source, or can be based on a reported revision level, patch level or update level, giving greater weight to the most recent of such events. A weight can also be based on the date of a report or most recent report update, or on the frequency of access to the report. 
     After weighting the accuracy of the information for each of the CIs, such as by using one or more of the weighting approaches described above, one of the sources may appear to be so much more reliable than all others that the data from such source will be selected as the correct data. Otherwise, it is necessary to compute an over-all confidence level, as shown by step  308  of  FIG. 3 . The confidence level may be determined from following the expression:
 
Confidence Level=( X *No. of writes to the  CI )/( Y *No. of  CI  Relationships)
 
where X and Y are constants. Thus, confidence level is increased by increasing the number of writes to the CR, and decreased by decreasing the number of relationships.
 
     As a further example, it is proposed that the configurable managed system  100  be changed by loading a specified software application into the hard drive of a server, wherein both the application software and the server are CIs of system  100 . To perform this task, the server hard drive must have enough available capacity to accommodate the size of the application. From steps  304  and  306  discussed above, change station  110  has determined that the application requires X MB of storage, with an 80% weighting that this information is correct. Similarly, change station  110  has determined that the hard drive of the server has available storage capacity of X MB, with a 70% weighting that this information is accurate. Accordingly, change station  110  carries out step  308  of  FIG. 3  by averaging the weights for the two CIs affected by the proposed task, to compute a confidence level of 75%. 
     At step  310 , it is necessary to select the minimum acceptable value of confidence level (CL min ) for the proposed change. This value could be predetermined for a possible or prospective change to a CI, and would correspond to the comparative amount of harm that would result if the change was carried out based on information found to be incorrect. In one embodiment, a table would be preconfigured to list a number of specified changes that could be made to system  100 . The table would further list the minimum confidence level values needed to allow respective listed changes to be made. The table (not shown) could reside in the CMBD, or elsewhere in system  100 . The determination of confidence level would generally be based on heuristics, or knowledge based on experience. It could also be based on collected historical data, that was continually updated. 
     For the above example, an inability to load the software application into the server would be a comparatively adverse consequence for system  100 . Accordingly, the minimum confidence level to allow this proposed task to proceed is usefully predetermined to be 70%. Such value would therefore be selected from the table by change station  110 , in accordance with step  310  of  FIG. 3 . At step  312 , the computed confidence level of 75% is compared with the 70% minimum acceptable level value. Since the computed value is greater, the change is allowed to be made, as shown by step  314 . Step  316  emphasizes that changes are disallowed, whenever the computed confidence level is less than the minimum acceptable value. 
     The following are examples of changes that a Change Manager could execute, after finding that the confidence level was at or above the minimum acceptable value:
         Install a Patch on a set of servers that hosts a business application.   Hot Swap Storage in an environment.   Upgrade a business software application to the next version/release.   Upgrade a router that is connected to several servers.       

     As a further feature, an embodiment of the invention can be configured to provide notice to a user, when a confidence level is found to be below the acceptable minimum. Also, a Change Manager may be authorized in certain situations to execute a change, even when the confidence level is less than the acceptable minimum value. For example, notwithstanding a low confidence level, the Change Manager may be willing to risk possible inaccuracies, where action is necessary to avoid hacking or the loss of important data. 
     The invention can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment containing both hardware and software elements. In a preferred embodiment, the invention is implemented in software, which includes but is not limited to firmware, resident software, microcode, etc. 
     Furthermore, the invention can take the form of a computer program product accessible from a computer-usable or computer-readable medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable medium can be any tangible apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. 
     The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read/write (CD-R/W) and DVD. 
     A data processing system suitable for storing and/or executing program code will include at least one processor coupled directly or indirectly to memory elements through a system bus. The memory elements can include local memory employed during actual execution of the program code, bulk storage, and cache memories which provide temporary storage of at least some program code in order to reduce the number of times code must be retrieved from bulk storage during execution. 
     Input/output or I/O devices (including but not limited to keyboards, displays, pointing devices, etc.) can be coupled to the system either directly or through intervening I/O controllers. 
     Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just a few of the currently available types of network adapters. 
     The description of the present invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to best explain the principles of the invention, the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.