Abstract:
A method for automatically resolving patch dependencies for a patch bundle is disclosed. The method includes recursively performing steps a) through b) until there are no more required dependencies to be added. Step a) includes ascertaining a first plurality of patches, the first plurality of patches representing patches currently in the patch bundle. Step b) includes adding patches that are required dependencies of the first plurality of patches to the first plurality of patches, the adding excluding any of the required dependencies that is already in the first plurality of patches prior to the adding or superseded by any patch in the first plurality of patches prior to the adding.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     In the computer field, patches are subsequent releases for an existing software product in order to fix problems or to add one or more new features. Patches may be employed to, for example, fix software bugs and/or implement new security features for an existing operating system or another application. The number of patches required to implement a given feature may vary from computer to computer, depending on the current configuration and how updated a given computer is (i.e., the computer&#39;s update status). For example, one computer may require a single patch to implement a particular feature, while another computer not kept up-to-date may require five different patches to both bring that computer up-to-date and to implement that particular feature.  
         [0002]     One way to implement a software patch is for manufacturers to provide all available software patches for a particular product to users, and each computer user must select the appropriate patch or patches for his computer. However, this primitive approach requires a high degree of skill on the part of the individual computer user, and is error-prone. Further, the number of available patches may be extremely large (perhaps thousands of patches, with each patch having a length of multiple megabytes of data, for a product such as an operating system, for example). The unwieldy size of such a patch renders the process intolerable even for the most skilled and careful user.  
         [0003]     The task is further complicated by the fact that a patch may depend on other patches and/or may have been fixed by yet other patches, all of which need to be installed together by the computer user for his computer to work properly.  
         [0004]      FIG. 1A  illustrates a portal-based approach to implementing patches, representing an improvement over the aforementioned manual technique. This is the current approach taken by software vendors such as Microsoft® for implementing patches to their Windows® operating system on users&#39; computers, for example. Using a network such as the internet  102 , users at computers  104 ,  106 , and  108  may access a portal  110 , which may be implemented as a website. Portal  110  then queries each individual computer, such as computer  104 , to ascertain its patch status, i.e., to ascertain what patch level has already been performed, if any, on computer  104 . Portal  110  may then ascertain, in view of the information obtained from computer  104  about its patch status, the set of patches required to implement a particular feature or a bug fix.  
         [0005]      FIG. 1B  shows the list of patches that each of computers  104 ,  106 , and  108  may need to apply in order to, for example, fix a particular software bug. As shown, computer  104  requires four patches ( 11 ,  17 ,  33 , and  41 ); computer  106  requires five patches ( 11 ,  17 ,  33 ,  41 ,  52 ), and computer  108  requires five different patches ( 11 ,  17 ,  33 ,  41 , and  49 ). As mentioned, different patch status in different computers necessitate different sets of patches to bring the computers up to the required functionality level.  
         [0006]     Although the portal-based approach of  FIG. 1A  streamlines the patch installation process somewhat, there are drawbacks. For example, the portal-based approach is not scalable for organizations that need to install patches in hundreds or thousands of computers at once. In some of these organizations, the task of installing patches may be delegated to an IT (Information Technology) staff, which may not have the manpower to timely update hundreds or thousands of computers one by one.  
         [0007]     Further, the portal-based approach requires access to the individual computers in order for the portal to ascertain the patch status thereon. For some organizations, such as governmental agencies, security concerns may require that these computers be inaccessible from outside, e.g., from the Internet. Even in organizations that allow their computers to be connected to the Internet, firewalls and other security measures may complicate access. Further, some computers may be inadvertently turned off by their users at the time when the portal needs to access those computers for patch status assessment. Without this data, the portal cannot come up with the required list of patches to be applied.  
         [0008]     Another approach involves the creation, distribution and on-site application of service packs. If a software product has been in use for some time, the manufacturer may decide to create a service pack, which encapsulate multiple patches over time, to be distributed to users. A service pack may be thought of as an atomic unit in that it needs to be applied in its entirety, and a user does not have an option to install only a portion of a service pack. Furthermore, service packs tend to be universal in nature and tend to be oriented toward software fixes or toward features that need to be distributed to all users.  
         [0009]     With respect to  FIG. 2 , service pack SP 1  represents an encapsulation of three patches:  11 ,  17 , and  33 . Suppose a software manufacturer decides that a new security feature is required to keep all users of a particular operating system safe and that the patches of FIG.  1 B are required to implement this new security feature. The user of computer  104  may then apply service pack SP 1  and patch  41  to activate the new security feature. The user of computer  106  may then apply service pack SP 1  and patches  41  and  52  to activate the new security feature. The user of computer  108  may then apply service pack SP 1  and patches  41  and  49  to activate the new security feature.  
         [0010]     As mentioned, service packs are typically defined by manufacturers for all users. A given service pack may not install all features desired by a particular user, may include a large number of features that the user does not want to burden his computer with, or may simply not include any feature desired by a particular user. Yet a user has no choice but to install the entire service pack, or must revert to the more cumbersome manual approach or portal-based approach to install just the individual patches to obtain the feature(s) he wants.  
         [0011]     Due to the static nature and large size of service packs, it is fairly common to need to install a stream of service packs and/or patches in order to obtain the desired functionality (e.g., the user must install service pack  1 , before service pack  2 , before installing patch  3  and so on). One way to avoid dealing with this issue is to use another approach known as “patch bubbling” or “supersession” which aims to create a cumulative and continuously updated set of changes to related components of the software being patched. In this system, each patch that is released is cumulative in that it contains all changes that have been made to the components it is delivering that have been released in previous patches. In this sense, if the components being delivered by a patch have been previously delivered by another patch, or set of patches, the current patch would supersede those previous patches. By supersede it is meant that it would deliver all the changes those previous patches delivered and thus those patches would become obsolete. As time progresses and those same components are patched again and again, it creates a stream of superseding patches where at any given time there is only 1 patch that is the most current cumulative version of the changes for a set of components and all other patches to those components have now been superseded by that patch. This cumulative patching system has been classically used by the HP-UX operating system (available from the Hewlett Packard Company of Palo Alto, Calif.), for example.  
         [0012]     A cumulative and continuously updated patch would include all components to date to achieve a particular purpose, with each individual component therein representing the most updated version of that particular component. With reference to  FIG. 3 , for example, if a first existing patch  1  ( 302 ) has components  11 ,  17 , and  33 . At some point after patch  1  is created, it becomes necessary to create a new patch  2  ( 304 ) that modifies components  33 ′,  41 ,  49 , and  52 , with component  33 ′ being the more updated version of component  33 ; However, if patch  2  only delivered the components it modified ( 304 ), it would not be cumulative.. Thus, through a process known conceptually as “patch bubbling” the modifications needed for patch  2  ( 304 ) are merged with the changes made in patch  1  ( 302 ) and the new patch  2 ′ ( 306 ) is created. As patch  2 ′ ( 306 ) contains all changes from patch  1  ( 302 ) in addition to the new changes needed for patch  2  ( 304 ) it can be said to be cumulative and to supersede patch  1  ( 302 ). This processing of “patch bubbling”, whereby once a component has been delivered in a patch with other components creates a set of components that must be delivered together in any future cumulative patches to any of those components. This example, components  11  and  17  were added to patch  2 ′ because patch  2  desired to make a change to component  33 . One of the drawbacks of such a system are the resulting ever-growing “patch bubbles” that result in patches inevitably growing larger and including more components as the supersession stream grows. The result is that at some point the number of components in each “patch bubbles” will become so large that creating new patches will become error prone and cumbersome due to a need to make unrelated changes to more than one of the components at that same time.  
         [0013]     The cumulative patch can then be furnished to each computer. Each computer may then extract the appropriate required constituent components (which may be different from computer to computer) to install in itself. The technology for such extraction and installation is already implemented in, for example, in the HP-UX® environment (HP-UX® represents an operating system available from the Hewlett-Packard company of Palo Alto, Calif.,), the command swinstall offers this functionality.  
         [0014]     A compromise approach involves keeping constituent patch bubbles that are not logically and/or functionally related (e.g., not related to the same functionality or same subsystem of the computer) separate and utilizing a patch bundle when necessary to deliver the separate patch streams together. This makes it easier to keep to keep the size of the individual patch streams manageable. It should be appreciated that although a patch bundle comprises a plurality of individual constituent patches, a patch bundle is treated, handled, and applied just like a regular patch after it is formed. One may think of a patch bundle as a composite patch, i.e., a composite of its individual constituent patches. Thus, the term patch and patch bundle may be used interchangeably herein, except in case where the distinction between a patch bundle and its constituent patches is clearly drawn.  
         [0015]     Under this approach, each patch bubble can be prevented from growing too large by use of maintaining separate patch bubbles with a dependency relationship. Thus, while it could be a noticeable drawback that each patch might no longer deliver the entire desired functionality, a patch bundle can be used to group the dependent patches together into a single composite patch without the drawback of having to maintain all the components of all the constituent patches from that time forward as a patch bubble. If the functionality from two different patches is required to implement a particular feature, a dependency relationship may be set up whereby a patch P 1  may be dependent on a patch P 2 .  
         [0016]     Referring now to  FIG. 4A , a single dependency relationship is shown between patch P 1  and patch P 2 , with patch P 1  being dependent on patch P 2  but not vice versa. Once both patches P 1  and P 2  are created, changes to the components in each patch may proceed independently. If the user already installed patch P 2 , and changes are made to one or more components within patch P 1  so as to give rise to a patch P 3  (which supersedes patch P 1 ), patch P 3  would inherit the same dependency as the patch it replaces (i.e., patch P 1 ). Thus patch P 3  would continue to be dependent on patch P 2 . Furthermore, if the user wishes to update the system with the functionality implemented by the latest version of the components within patch P 1 , only patch P 3  needs to be applied since patch P 2  has already been applied previously and no change has been made to it. Note that the superseded patch P 1  is no longer utilized.  
         [0017]     Likewise, if changes are made to one or more components within patch P 3  at a later time so as to give rise to a patch P 4  (which supersedes batch P 3 ), patch P 4  would inherit the same dependency as the patch it replaces (i.e., patch P 3 ). Thus patch P 4  would again be dependent on patch P 2 . If the user wishes to update the system that only has patch P 2  installed with the functionality implemented by the latest version of the patches within patch PI, only patch P 4  now needs to be applied since patch P 2  has already been applied previously and no change has been made to it. Note that the superseded patches P 1  and P 3  are no longer utilized.  
         [0018]     So far, the dependency has only been shown in a single direction (e.g., from patch P 1  and its superseding patches P 3  and P 4  to patch P 2 ). One may also have bidirectional dependencies.  FIG. 4B  shows such a scenario wherein patch P 5  and P 6  depend on one another. In this case, any version of each patch stream (represented in  FIG. 4B  by the vertical columns) will resolve the dependency; however due to the bidirectional dependency, no patch from either stream can be installed without also installing a patch from the other stream. For example, if a user wanted to install P 5  that user would also have to install their choice of P 6 , P 9 , or P 10 . The choice for which of P 6 , P 9 , or P 10  to install is completely up to the end user as any one of the three would fulfill the dependency in this example. To continue this scenario, if the user selected to install P 9  along with P 5  that user would have successfully resolved the dependency. From that point, that user could additionally install P 7  or P 8  at any time without having to worry about resolving the dependency again because P 9  would already be applied to the system.  
         [0019]     Dependencies may be even more complex.  FIG. 4C  show a dependency tree wherein patch P 11  depends on patch P 12 , which in turn depends on patch P 13  and patch P 14 . Patch P 14  depends on patch P 15  and patch P 16  while patch P 13  depends on patch P 17 . Further, patch P 14  depends on patch P 18 ′, and patch P 15  depends on patch P 18 . In this scenario, patch P 18 ′ is actually the latest version of patch P 18 . Thus, it is important in this case to install only patch P 18 ′ to avoid conflicts and to allow patch P 15  to depend on the installed patch P 18 ′ instead of patch P 18 , which has been superseded.  
         [0020]      FIGS. 4A-4C  are shown to illustrate only some exemplary dependencies. Dependencies can be even more complex and may involve a very large number of entities depending on one another in various combinations and multiple levels of dependency.  
         [0021]     The existence of dependencies complicates the process of patch installation, particular when patches are installed using patch bundles and/or individual patches. This is because when a patch bundle and/or individual patch(es) are applied, all dependencies need to be properly resolved and the patch bundle(s) and the patch(es) that were depended upon need to also be installed. In a multi-level dependency situation such as the case shown in  FIG. 4C , the resolution of at one level (i.e., the resolution of dependencies for patch P 11 ) may reveal that further resolution is needed at a lower level (i.e., patch P 12  upon which patch P 11  depends actually has its own dependencies that need to be resolved).  
         [0022]     In the prior art, a technique for resolving dependencies has been developed.  FIG. 5A  shows an implementation of the dependency resolution technique. In step  502 , the patch (which may also be a patch bundle) is provided as an input. In step  504 , the patch documentation is extracted.  
         [0023]     Since each patch is furnished with documentation that describes among other things, the patch name, the patch dependencies, the superseding data, and optional dependency data, an appropriate tool may be employed to parse the patch documentation to provide these pieces of data. To elaborate, the patch name uniquely identifies the patch, such as patch  174  for example. The patch dependencies uniquely identify the patch(es) upon which patch  174  depends. These patches may be, for example, patch  178  and patch  191 . The superseding data identifies the patches that have been superseded by the current patch  174 . The optional dependency data describes any other dependent patches (e.g., patches  211  and  342 ) that must also be applied if certain optional features are selected when installing the current patch  174 .  
         [0024]     In one implementation in the HP-UX® environment (HP-UX® represents an operating system available from the Hewlett-Packard company of Palo Alto, Calif.), the tool Swlist is employed to read the documentation data from the readme.txt file of a patch. In one implementation, the command swlist-a readme-s&lt;path_to_file&gt; may be employed. Once the documentation data is read, expression matching or another technique may be employed to parse the file read to obtain the aforementioned patch name, patch dependencies, and optional dependencies.  
         [0025]     In step  506 , the required dependencies (i.e., the required dependent patches) are determined. This step is discussed in greater detail in  FIG. 5B  herein. In step  508 , the operator is presented with options and the associated optional dependencies. If the operator wishes to resolve the optional dependencies ( 510 ), the operator may then manually determine ( 512 ) the optional dependencies depending on the options chosen, if any. The end product is a list of dependent patches ( 515 ) that must also be installed for the current patch to apply properly.  
         [0026]      FIG. 5B  shows in greater detail step  506  (determining the required dependencies). In step  552 , the constituent patches in the provided patch bundle are identified. When the provided patch is itself a patch bundle, there are constituent patches, and these constituent patches are identified in step  552 . In step  554 , the patches that have been superseded by constituent patches of the current patch bundle are determined. In step  556 , the complete list of required dependencies for the current patch bundle is determined. In step  558 , the list of required dependencies that are not in the current patch bundle or superseded by patches in the current patch bundle is determined. Thereafter, the method returns to step  508  of  FIG. 5A  to continue to dependency resolution technique.  
         [0027]     Although an operator can employ the algorithm of  FIGS. 5A and 5B  to resolve dependencies of a patch/patch bundle to ascertain additional patches/patch bundles that need to be applied, the process is still laborious and time-consuming. This is particularly in the case where there are multiple levels of dependencies (such as the situation shown in  FIG. 4C ). When there are multiple levels of dependencies, the operator needs to obtain the dependent patches/bundles, apply the algorithm of  FIGS. 5A and 5B  to each new dependent patch/bundle found in order to ascertain whether there are even more dependent patches/bundles that need to be installed. If the application of the algorithm of  FIGS. 5A and 5B  to the dependent patches/bundles yield even more dependent patches/bundles, the operator needs to obtain those additional dependent patches/bundles and apply the algorithm of  FIGS. 5A and 5B  again.  
       SUMMARY OF INVENTION  
       [0028]     The invention relates, in one embodiment, to a method for automatically resolving patch dependencies for a patch bundle. The method includes recursively performing steps a) through b) until there are no more required dependencies to be added. Step a) includes ascertaining a first plurality of patches, the first plurality of patches representing patches currently in the patch bundle. Step b) includes adding patches that are required dependencies of the first plurality of patches to the first plurality of patches, the adding excluding any of the required dependencies that is already in the first plurality of patches prior to the adding or superseded by any patch in the first plurality of patches prior to the adding.  
         [0029]     In another embodiment, the invention relates to a computer-implemented method for automatically resolving patch dependencies for a patch bundle. The method includes a) ascertaining a first plurality of patches, the first plurality of patches representing patches in the patch bundle. The method also includes b) adding a set of superseded patches to a list of supersedes, the set of superseded patches representing patches that are superseded by the first plurality of patches and not already in the list of supersedes. The method additionally includes c) ascertaining a second plurality of patches, the second plurality of patches represent required dependencies of the first plurality of patches that are neither in the first plurality of patches nor in the list of supersedes. The method also includes d) adding, if the second plurality of patches has at least one member, the second plurality of patches to the first plurality of patches, thereby increasing a number of members in the first plurality of patches and repeating step b), step c) and step d).  
         [0030]     In another embodiment, the invention relates to an article of manufacture comprising a program storage medium having computer readable code embodied therein, the computer readable code being configured to automatically resolve patch dependencies for a patch bundle. There is included computer readable code for recursively executing computer readable code section (a) through computer readable code section (b) until there are no more required dependencies to be added. The computer readable code section (a) includes computer readable code for ascertaining a first plurality of patches, the first plurality of patches representing patches currently in the patch bundle. The computer readable code section (b) includes computer readable code for adding patches that are required dependencies of the first plurality of patches to the first plurality of patches, the adding excluding any of the required dependencies that is already in the first plurality of patches prior to the adding or superseded by any patch in the first plurality of patches prior to the adding.  
         [0031]     These and other features of the present invention will be described in more detail below in the detailed description of the invention and in conjunction with the following figures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0032]     The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:  
         [0033]      FIGS. 1A and 1B  illustrate a prior art portal-based approach to implementing patches  
         [0034]      FIG. 2  illustrates a prior art approach involving service packs.  
         [0035]      FIG. 3  shows a prior art approach employing cumulative patches.  
         [0036]      FIGS. 4A and 4B  and  4 C illustrate the concept of dependencies.  
         [0037]      FIGS. 5A and 5B  illustrate the prior art approach for resolving patch dependencies.  
         [0038]      FIG. 6  illustrates a computer system environment for practicing embodiments of the present invention.  
         [0039]      FIG. 7  illustrates an exemplar plurality of patches in which there are superseding and dependent relationships to facilitate discussion of embodiments of the present invention.  
         [0040]      FIGS. 8A and 8B  illustrate, in accordance with embodiments of the present invention, an implementation of the recursive customizable all-inclusive patch formation algorithm.  
         [0041]      FIG. 9  illustrates, in accordance with another embodiment of the invention, the steps for automatically resolving required dependencies.  
     
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       [0042]     The present invention will now be described in detail with reference to a few embodiments thereof as illustrated in the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process steps and/or structures have not been described in detail in order to not unnecessarily obscure the present invention.  
         [0043]     Various embodiments are described hereinbelow, including methods and techniques. It should be kept in mind that the invention may also cover articles of manufacture that includes a computer readable medium on which computer-readable instructions for carrying out embodiments of the inventive technique are stored. The computer readable medium may include, for example, semiconductor, magnetic, opto-magnetic, optical, or other forms of computer readable medium for storing computer readable code. Further, the invention may also cover apparatuses for practicing embodiments of the invention. Such apparatus may include circuits, dedicated and/or programmable, to carry out tasks pertaining to embodiments of the invention. Examples of such apparatus include a general purpose computer and/or a dedicated computing device when appropriately programmed and may include a combination of a computer/computing device and dedicated/programmable circuits adapted for the various tasks pertaining to embodiments of the invention.  
         [0044]     In accordance with embodiments of the present invention, there are provided arrangements and techniques for automatically creating a customizable all-inclusive patch (CAIP) to implement a user-specified feature. The inventive process of embodiments of the invention is highly automated and configured to produce customizable CAIP. In an embodiment, the user enters the desired patch level, and the CAIP is automatically created as an output, ready to be applied to any computer. Thus, unless there is any option that the operator wishes to have implemented, a CAIP can be created in an embodiment without any operator input once the patch level is specified.  
         [0045]     In another embodiment, the operator may be furnished with operator-selectable options and associated patches. The selection of one or more options would automatically cause those associated patches and any other dependencies that depend on the associated patches to be automatically included in the CAIP produced.  
         [0046]     Note that the CAIP formed in accordance with embodiments of the present invention would have no external dependencies, i.e., the CAIP has all dependent patches, rendering it unnecessary to apply any additional patch to achieve the desired user-specified feature. Furthermore, the constituent patches in the CAIP are represented in their most up-to-date version, with superseded patches automatically removed from the CAIP so as to avoid conflicts in the computer in which the CAIP is applied.  
         [0047]     It is realized by the inventors herein although the algorithm of  FIGS. 5A and 5B  can be applied to a specified patch bundle to obtain a list of dependencies, further improvement is desirable to further automate the patch application process. If the specified patch has dependent patches, these dependent patches also need to be examined, using the algorithms of  FIGS. 5A and 5B , to determine whether they themselves have dependencies. If there are multiple levels of dependencies, multiple cycles of manual application of the algorithms of  FIGS. 5A and 5B  and manual examination of the dependencies found may need to be performed. This is disadvantageous.  
         [0048]     Additionally, the end product produced by the algorithm of  FIGS. 5A and 5B  is a list of dependencies. Further manual work needs to be performed in order to eliminate from the list patches that have been superseded by other patches in the list. The operator must then obtain all the required patches and put them together using a tool such as swpackage, which is available from the Hewlett-Packard Company of Palo Alto, Calif., to create a patch bundle that can be applied to computers in the field.  
         [0049]     Accordingly, the inventors herein have made additional improvements, which will be discussed herein below.  FIG. 6  shows, in accordance with an embodiment of the invention, an arrangement for creating the CAIP. Block  602  represents a computer system for executing the CAIP-forming algorithm (shown symbolically by reference number  604 ). The operator inputs the desired patch level (shown symbolically by reference number  606 ) using, for example, operator console  608 . The algorithm interacts with a patch library  610  to automatically produce a CAIP, which is shown symbolically by reference number  612 . Note that unlike the situation in  FIGS. 5A and 5B , embodiments of the invention automatically, without requiring user intervention, creates an executable CAIP irrespective whether there are multiple levels of dependencies and whether some of the patches discovered when resolving dependencies are superseded by other patches.  
         [0050]      FIGS. 8A and 8B  illustrate, in accordance with embodiments of the present invention, implementations of the recursive CAIP formation algorithm. To illustrate the operation of the recursive CAIP formation algorithm, consider the following example, which is illustrated in  FIG. 7 . Suppose the user wishes to apply patch bundle New_Bundle, which has constituent patches  274  and  281 . The documentation of patch  274  indicates that patch  274  supersedes patches  251  and  232 . Further, the documentation of patch  274  indicates that patch  274  depends on patches  240  and  260 . The documentation of patch  281  indicates that patch  281  supersedes patch  256 . Further, the documentation of patch  281  indicates that patch  281  depends on patch  237 . Patch  240  is dependent, as indicated in its documentation data, on patches  237 ,  211 , and  251 . Further, patch  240  supersedes patch  237 .  
         [0051]     In step  802 , the patch (which may also be a patch bundle) is provided as an input. In the present example, patch bundle New_Bundle is specified in step  802 .  
         [0052]     In step  804 , the patch documentation is extracted. In the case of a patch bundle, such as New_Bundle, the documentation of the constituent patches are read. As mentioned, since each patch is furnished with documentation that describes among other things, the patch name, the patch dependencies, the superseding data, and optional dependency data, an appropriate tool may be employed to parse the patch documentation to provide these pieces of data. To elaborate, the patch name uniquely identifies the patch, such as patch  274 . The patch dependencies uniquely identify the patch(es) upon which patch  274  depends. The superseding data identifies the patches that have been superseded by the current patch  274 . In the present example, the superseded patches are, for example,  251  and  232 . The optional dependency data describes any other dependent patches that must also be applied if certain optional features are selected when installing the current patches.  
         [0053]     In one implementation in the HP-UX® environment (HP-UX® represents an operating system available from the Hewlett-Packard company of Palo Alto, Calif.), the tool swlist is employed to read the documentation data from the readme.txt file of a patch. In one implementation, the command swlist-a readme-s&lt;path_to_file&gt; may be employed. Once the documentation data is read, expression matching or another technique may be employed to parse the file read to obtain the aforementioned patch name, patch dependencies, supersedes, and optional dependencies.  
         [0054]     In step  806 , the required dependencies (i.e., the required dependent patches) are determined. This step is discussed in greater detail in  FIG. 8B  herein. In step  808 , the operator is presented with options and the associated optional dependencies. If the user chooses any option, their dependencies are sent to step  806  to resolve all the dependencies that may be dependent thereon. The end product is patch that contains all required dependencies (and any optional dependencies if one or more options are chosen). The patch creator can then distribute the patch using any modality, including the same modality in which the patch is applied in an embodiment, to allow the patch to be applied to any computer without regard to a specific computer&#39;s current patch status (since commercially available software, such as the aforementioned swinstall, within each computer would know which patch(es) that specific computer would need to achieve the patch level implemented by the patch).  
         [0055]      FIG. 8B  shows in greater detail step  806  (determining the required dependencies). In step  852 , the constituent patches in the provided patch bundle are identified. When the provided patch is itself a patch bundle, there are constituent patches, and these constituent patches are identified in step  852 . In the present case, patches  274  and  281  are identified in step  852 .  
         [0056]     In step  854 , the patches that have been superseded by the current patch bundle are determined. At this stage, patches  251 ,  232 , and  256  are identified since they are superseded as indicated by the documentation data of patches  274  and  281   
         [0057]     In step  856 , the complete list of required dependencies for the current patch bundle is determined. At this stage, patches  240 ,  260 , and  237  are identified. In step  858 , the list of required dependencies that are not in the current patch bundle or superseded by patches in the current patch bundle is determined. In other words, the list of dependencies identified in step  856  are checked against the current list of patches in the patch bundle (which grows as time progresses if there are unresolved dependencies, as will be seen in step  862 ) and against the current list of superseded patches (which also grows over time as additional superseded patches are found in step  802  for each iteration as will be seen later).  
         [0058]     In this case, patches  240 ,  260 , and  237  are not in the current list of bundle patches (current membership of current list of bundle patches =patches  274  and  281 ) or the current list superseded patches (membership of current list superseded patches =patches  251 ,  232 , and  256 ). Thus, the list of required dependencies is unchanged from step  856  to step  858 , with its membership still comprising patches  240 ,  260 , and  237  after step  858 .  
         [0059]     Since the list of required dependencies after step  858  is not empty (as determined by step  860 ), the patches in the list (i.e., patches  240 ,  260 , and  237 ) are fetched in the next step  862 . In one embodiment, the patches may be fetched from an FTP server although any file transfer technique may be employed to obtain these patches from a patch depository, such as a patch library. Note that this step  862  is performed automatically without operator intervention.  
         [0060]     In step  864 , the patches in the list of required dependencies (e.g., patches  240 ,  260 , and  237 ) are added to the current list of bundle patches. Thus, the current list of bundle patches now comprises patches  274 ,  281 ,  240 ,  260 , and  237 . Next, in step  866 , the patch documentation for the new patches in the current list of bundle patches (i.e., documentation for patches  240 ,  260 , and  237 ) is read and parsed, in the manner discussed earlier in connection with step  804 .  
         [0061]     The method then returns to step  852  to ascertain the unresolved dependencies for this patch bundle (whose membership was changed via step  864 ). In step  852 , the list of patches in the current bundle is now determined. The determination in this iteration yields patches  274 ,  281 ,  240 ,  260 , and  237 .  
         [0062]     Next, the patches that have been superseded by patches in the current bundle are determined in step  854 . The determination in this iteration yields patches  251 ,  232 ,  256  and also patch  237  (superseded by patch  240 , which is new to the current list of bundle patches).  
         [0063]     Next, in step  856 , the complete list of required dependencies for the patches in the current bundle is determined. Since the current bundle now contains patches  274 ,  281 ,  240 ,  260 , and  237 , their dependencies are patches  240  and  260  (for patch  274 ),  237  (for patch  281 ),  237 ,  211 , and  251  (for patch  240 ). Next, in step  858 , the list of required dependencies that are not in the current patch bundle or superseded by patches in the current patch bundle is determined. In other words, the list of dependencies identified in step  856  are checked against the current list of patches in the patch bundle and against the current list of superseded patches.  
         [0064]     In this case, patches  240 ,  260 ,  237  are both in the current list of bundle patches (current membership of current list of bundle patches=patches  274 ,  281 ,  240 ,  260 , and  237 ) and in the list of required dependencies determined in step  856  (current membership of current list of required dependencies= 240 ,  260 ,  237 ,  237 ,  211 , and  251 ). Accordingly, patches  240 ,  260 , and  237  are eliminated and only patches  211  and  251  remain. Additionally, the current list superseded patches contains patch  251  (membership of current list of superseded patches=patches  251 ,  232 ,  256 , and  237 ). Accordingly, patch  251  is removed and the list of required dependencies contains only patch  211  after step  858 , with patch  251  removed.  
         [0065]     Since the list of required dependencies after step  858  is not empty (as determined by step  860 ), the patches in the list of required dependencies that remain (i.e., patches  256  and  211 ) are fetched in the next step  862 . Again, note that this step  862  is performed automatically without operator intervention.  
         [0066]     In step  864 , the patches in the list of required dependencies (e.g., patches  256 , and  211 ) are added to the current list of bundle patches. Thus, the current list of bundle patches comprises now patches  274 ,  281 ,  240 ,  260 ,  237 , and  211 . Next, in step  866 , the patch documentation for the new patches in the current list of bundle patches (i.e., documentation for patch  211 ) is read and parsed in the manner discussed earlier in step  804 .  
         [0067]     The method then returns to step  852  to ascertain the unresolved dependencies for this patch bundle (whose membership was changed via step  864  in the last iteration). In step  852 , the list of patches in the current bundle is now determined. The determination in this iteration yields patches  274 ,  281 ,  240 ,  260 ,  237 , and  211 . Next, the patches that have been superseded by patches in the current bundle are determined in step  854 . The determination in this iteration yields patches  251 ,  232 ,  256  and  237 .  
         [0068]     Next, in step  856 , the complete list of required dependencies for patches in the current bundle is determined. Since the current bundle now contains patches  274 ,  281 ,  240 ,  260 ,  237 , and  211 , their dependencies are patches  240  and  260  (for patch  274 ),  237  (for patch  281 ),  237 ,  211 , and  251  (for patch  240 ).  
         [0069]     Next, in step  858 , the list of required dependencies that are not in the current patch bundle or superseded by patches in the current patch bundle is determined. Patches  240 ,  260 ,  237 , and  211  are found in the current patch bundle (current membership of current patch bundle= 274 ,  281 ,  240 ,  260 ,  237 , and  211 ) and are thus eliminated from the list of required dependencies. Patch  251  remains. However, patch  251  is found in the list of superseded patches (membership of current list of superseded patches=patches  251 ,  232 ,  256 , and  237 ). Accordingly, patch  251  is removed and the list of required dependencies is empty after this iteration.  
         [0070]     Since the list of dependencies is now empty (as determined by step  860 ), the method proceeds to step  870  wherein final set of patches and patch bundle (s) discovered while iterating through  FIG. 8B  are examined to determine if any patches in that set supersede other patches in that set. Since having 2 patches from the same supersession stream can cause unnecessary confusion, it is best to keep only the newest patch in the stream and remove all others. In this example, both patches  237  and  240  are in the current patch bundle at step  870 . Since patch  237  was identified as a patch that is superseded by patch  240  per  FIG. 7 , this step would detect this and remove patch  237  from the patch bundle. This supersession check could be performed repeatedly at step  858 , but performing the check at  870 , it only needs to be performed once.  
         [0071]     Note that in the example of  FIG. 8B , the list of constituent patches in the bundle ( 852 ), the list of superseded patches ( 854 ) and the list of required dependencies ( 856 ) are determined anew for each recursion. However, it is possible to improve efficiency by determining only the newly added patches and adding those to the list of patches that existed prior to adding (thereby deriving the constituent patches in the current bundle), determining the patches superseded by those newly added patches and adding them to the existing list of supersedes (thereby updating the list of supersedes), and determining the patches that are required dependencies of those newly added patches and adding them to the existing list of required dependencies (thereby updating the list of required dependencies).  
         [0072]      FIG. 9  shows, in accordance with another embodiment of the invention, the steps for automatically resolving required dependencies. In step  902 , the patches in the patch bundle are ascertained. In step  904 , the method recursively drills down to add patches that are required dependencies of patches in the patch bundle to the patch bundle until there are no more dependent patches to be added. At each recursion, dependent patches that are duplicates of or superseded by patches in the current patch bundle are not added to the patch bundle.  
         [0073]     As can be appreciated from the foregoing, embodiments of the invention allows the complete patch bundle, including all required dependencies to be obtained automatically without the intervention of the human operator. If optional dependencies are desired, the human operator is given the option to add the optional dependencies, thereby obtaining a patch bundle that is complete with all required and desired dependencies.  
         [0074]     While this invention has been described in terms of several embodiments, there are alterations, permutations, and equivalents which fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing the methods and apparatuses of the present invention. It is therefore intended that the following appended claims be interpreted as including all such alterations, permutations, and equivalents as fall within the true spirit and scope of the present invention.