Abstract:
A system for installing application components in a target platform can include a component installation engine configured to install application components and respective dependencies over a component distribution system. A script processor can be coupled to the engine and programmed to parse target specific installation scripts to identify both a listing of dependencies for the application components and at least one specified relationship between the application components and individual ones of the respective dependencies. Finally, a requirements verification processor can be programmed to enforce both target platform requirements for installing the application components and the at least one specified relationship prior to installing the application components.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Statement of the Technical Field  
         [0002]     The present invention relates to the field of application component distribution, and more particularly to the target platform neutral management of application component requirements during the installation of an application component.  
         [0003]     2. Description of the Related Art  
         [0004]     Though often overlooked, application installation is a prerequisite to interacting with a software application. Specifically, in most circumstances, an application can be properly executed only subsequent to the completion of a successful installation process. At the minimum, a typical software application installation requires a transfer of files to the file structure of a computing system, and the configuration of the computing system to particularly interact with the software application. Ordinarily, the configuration of the computing system includes the addition or modification of registry settings, the addition or modification of entries to one or more initialization files, or both.  
         [0005]     In the context of an application installation meant to upgrade the components of an application, oftentimes, simply replacing application out-dated versions of application components with newer versions of components will not alone suffice as a complete application upgrade. Rather, in an era of code re-use, shared libraries, and interdependent program objects, replacing a single application component can have a dramatic effect upon other separate, but independent applications. Common disastrous consequences include altered and now incompatible application programming interfaces (APIs), re-positioned application objects, and removed application objects. In all cases, an application dependency can be broken simply by upgrading the application components of another, unrelated application.  
         [0006]     Whereas application component upgrades can be problematic generally, in an autonomic system, the problem can be particularly acute. For the uninitiated, autonomic computing systems self-regulate, self-repair and respond to changing conditions, without requiring any conscious effort on the part of the computing system operator. To that end, the computing system itself can bear the responsibility of coping with its own complexity. The crux of autonomic computing relates to eight principal characteristics:  
         [0007]     I. The system must “know itself” and include those system components which also possess a system identify.  
         [0008]     II. The system must be able to configure and reconfigure itself under varying and unpredictable conditions.  
         [0009]     III. The system must never settle for the status quo and the system must always look for ways to optimize its workings.  
         [0010]     IV. The system must be self-healing and capable of recovering from routine and extraordinary events that might cause some of its parts to malfunction.  
         [0011]     V. The system must be an expert in self-protection.  
         [0012]     VI. The system must know its environment and the context surrounding its activity, and act accordingly.  
         [0013]     VII. The system must adhere to open standards.  
         [0014]     VIII. The system must anticipate the optimized resources needed while keeping its complexity hidden from the user.  
         [0015]     Thus, in keeping with the principles of autonomic computing, the installation of application components must not only account for the seamless installation and configuration of the application components, but also the impact of the installation upon existing applications in the target platform. Moreover, it can be important that dependencies required for the nominal operation of the application components exist within the target platform, or can be accessed from the target platform. Finally, it can be critical that the infrastructure provided by the target platform, including its computing resources, meets the resource requirements of the application components. Hence, it will be of paramount concern to the autonomic system that the target platform itself will not become “broken” in consequence of the installation of the application components.  
         [0016]     Presently, several application upgrade strategies exist. One such well-known strategy includes the venerable “ReadMe” file. In this strategy, software developers provide a list, typically as standard prose, of components in the application which are to be installed, the required pre-requisite components and any resource requirements to be provided by the target platform. Subsequently, during installation, an application administrator can peruse the contents of the list to determine the nature of the component installation. As it will be recognized by one skilled in the art, however, the creation and use of a conventional ReadMe file can be both tedious and unreliable.  
         [0017]     It will also be well understood by those skilled artisans that automated methods exist at least to remediate the tedium associated with the conventional ReadMe file. Specifically, various programming tools have been developed through which application component dependencies can be identified among system elements. Prior to any installation effort, the programming tool can be executed so as to determine the risk of undertaking the application installation. Still, this process lacks the granularity necessary to definitively assess the changing nature of dependencies. Moreover, modern automated methods are target platform specific. As a result, modern automated methods remain product level solutions which are ill-suited for the “write once run anywhere” nature of modern enterprise computing.  
       SUMMARY OF THE INVENTION  
       [0018]     The present invention addresses the deficiencies of the art in respect to application component distribution and provides a novel and non-obvious method, system and apparatus for installing an application component from a platform neutral semantic model for the application component. In accordance with the present invention, a component installation method can include identifying target platform requirements for installation a subject application component within a target specific installation script, and further identifying a listing of dependencies for the subject application and at least one specified relationship between the subject application and individual ones of the dependencies. Notably, the at least one specified relationship can be a relationship selected from the group consisting of a containment relationship, a usage relationship, a contradictory relationship and an equivalence relationship.  
         [0019]     Both the target platform requirements and the specified relationship can be enforced prior to installing the subject application component. In this regard, the installation can be aborted where either one of the target platform requirements and the at least one specified relationship cannot be enforced. In a preferred embodiment, the enforcing step can include determining whether all required ones of the dependencies can be accessed in the target platform. For each required one of the dependencies which cannot be accessed in the target platform, the required one of the dependencies can be located and installed in the target platform. Moreover, the determining step can include the step of querying a registry of installed components in the target platform to identify components which have been installed in the target platform.  
         [0020]     A system for installing application components in a target platform can include a component installation engine configured to install application components and respective dependencies over a component distribution system. A script processor can be coupled to the engine and programmed to parse target specific installation scripts to identify both a listing of dependencies for the application components and at least one specified relationship between the application components and individual ones of the respective dependencies. Finally, a requirements verification processor can be programmed to enforce both target platform requirements for installing the application components and the at least one specified relationship prior to installing the application components.  
         [0021]     Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]     The accompanying drawings, which are incorporated in and constitute part of the this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred, it being understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:  
         [0023]      FIG. 1  is a schematic illustration of a script generation engine disposed within an application component distribution system;  
         [0024]      FIG. 2  is a block diagram illustrating a system for installing an application component according to a target specific installation script produced by the engine of  FIG. 1 ; and,  
         [0025]      FIG. 3  is a flow chart illustrating a process for optimally installing an application component to a target platform according to the system of  FIG. 2 .  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]     The present invention is a system, method and apparatus for optimally installing an application component in a target platform based upon a platform neutral specification of the installation process for the application component. In accordance with the present invention, a target specific installation script can be generated from a platform neutral model of the application component and its dependent components. The target specific installation script further can specify a minimum requisite configuration for the target platform. Upon installation, first the target platform can be inspected to ensure that the resources available within the target platform meet the minimum requisite configuration. Subsequently, the target platform can be inspected to ensure that the required dependencies can be accessed in the target platform and that the dependency relationships specified within the target specific installation script are enforced.  
         [0027]     In this regard, the dependency relationships can include not only containment relationships in which one component can depend upon the operation of another, but also usage relationships in which one component can be functional only in the presence of another component, contradictory relationships in which one component cannot be functional in the presence of another component, and equivalence relationships in which one component can be substituted for another component. In any case, where a dependency is lacking for a containment or usage relationship, the dependency can be located and loaded excepting where a suitable equivalent component can be substituted for the missing component. Only where one or more of the specified dependency relationships or the minimum requisite configuration cannot be satisfied can the installation of the application component fail.  
         [0028]      FIG. 1  is a schematic illustration of a script generation engine disposed within an application component distribution system. The system can include a script generation engine  200  coupled to a source platform  150  configured for distributing subject application components  130  to individual target platform environments  190  over a component distribution network  180 . The target platform environments  190  can range from an individual application hosting environment to a distributed and coordinated network of application hosting environments, to a cluster of application hosting environments. Additionally, the component distribution network  180  can range from a simple Intranet to a complex data communications network.  
         [0029]     The source platform  150  can be coupled to the components  130 . The components can include application logic compartmentalized into one or more objects which can operate within an execution environment such as a virtual machine. As it will be recognized by the skilled artisan, each of the components  130 , can have specific resource requirements within the target platform  190 , including a minimum amount of accessible memory, fixed storage and network bandwidth, to name a few. Additionally, each of the components  130  can depend upon the operation of one or more other components  130 . For example, a Web application server can depend upon the operation of a database server, and a mail server can depend upon the availability of a data communications stack.  
         [0030]     Inasmuch as the components  130  can have both a set of target platform requirements and component dependencies, target platform requirements  140  can be recorded for each of the components  130  and stored within a repository  120  communicatively associated with the script generation engine  200 . Preferably, the target platform requirements  140  can include deployment target requirements. The component dependencies, by comparison, can include a specification of the relationship between the components, including their respective ordering, any pre-requisite components required for the operation of other ones of the components, whether certain components are to be excluded from operation during the operation of other components, and equivalence among components such that one component can be interchanged for another.  
         [0031]     Through the communicative association between the script generation engine  200  and the repository  120 , the repository  120  can be accessed by a script generation process (not shown) in the script generation engine  200  based upon a specification of components. Within the repository  120 , a model of functional dependencies between components  130  also can be stored. Preferably, the model along with the requirements can be formatted within a markup language with components specified according to their respective network addressing scheme. In this way, one familiar with the schema for the markup language document can readily parse the document to identify the hierarchical model of interdependent application components and their respective target platform requirements.  
         [0032]     Significantly, a transformation engine  110  further can be communicatively associated with the script generation engine  200  and coupled to the repository  120 . The transformation engine  110  can resolve mappings between the dependency relationships specified in the repository  120  and actual instructions (not shown) for installing a corresponding one of the components  130  in the target platform  190 . Preferably, the transformation engine can generate a markup language formatted target specific script  160  for a selected set of components  170  to be installed in the target platform  190 . The script  160  can include specific instructions for deploying the components  170  in the target platform  190 . The instructions not only can identify pre-requisite minimum resources within the target platform  190 , but also the script can identify dependencies required for the operation of the components  170 , interchangeable ones of those dependencies, contradictions between the components  170  and already existing components in the target platform  190 , and limitations on usage of one or more of the components  170 .  
         [0033]      FIG. 2  is a block diagram illustrating a system for installing an application component according to a target specific installation script produced by the engine of  FIG. 1 . Referring now to  FIG. 2 , a component installation engine  200  can process the target specific script  210  produced in behalf of the component distribution system  270 . In particular, the component installation engine  200  can parse the target specific script  210  first to identify a set of target platform requirements, such as minimum available memory, fixed storage space, minimum processor resources, etc. To that end, the component installation engine  200  can inspect the configuration of the target platform  240 . Where the configuration of the target platform  240  cannot satisfy the requisite configuration specified within the target specific script  210 , the installation can abort.  
         [0034]     Otherwise, the component installation engine  200  can identify within the target specific script  210  a listing of dependencies  230  whose functional operation within target platform  240  will be required for the nominal operation of the application component  220 . In support of this function, the component installation engine  200  can query the repository  250  to recall the semantic model  260  for the interdependent hierarchy of components  230  required by the installation of the application component  220 . The model  260  can be compared to a registry  280  of installed components to determine whether the required dependencies  230  have been installed in the target platform  240 , or whether any one or more missing ones of the dependencies  230  can be located and installed.  
         [0035]     Notably, to the extent that updates or patches to already installed ones of the dependencies  230  can be discovered in the repository  250 , the updates and patches automatically can be applied to the already installed dependencies  230 . Of course, so much would be the case only where a network connection is present. Where no network connection is present, retrieving patches from a network repository will not be possible. In any event, where the required interdependencies or suitable equivalent dependencies can be installed in the order prescribed by target specific script  210 , the application component  220  can be installed to the target platform  240  and the installation can be written to the registry  280 . Otherwise, the installation process can be deemed to have failed and the installation of the application component  220  can be aborted.  
         [0036]     In more particular illustration of the operation of the system of  FIG. 2 ,  FIG. 3  is a flow chart illustrating a process for optimally installing an application component to a target platform according to the system of  FIG. 2 . Beginning in block  305  the target specific installation script for an application component can be loaded. In block  310 , the platform requirements for the application component and its dependencies can be identified. In block  315 , the target platform requirements can be compared to the available resources of the target platform. If in block  320 , the target platform cannot provide the requisite level of computing resources, in block  365  a failure notification can be generated and in block  370  the process can end. Otherwise, the process can continue in blocks  325  through  365 .  
         [0037]     If in block  320  the target platform can provide the requisite level of computing resources, in block  325  the dependencies for the application component can be identified. In this regard, not only can directly specified dependencies be identified, but also all sub-dependencies can be identified by traversing the model of the dependency hierarchy for the application component. Specifically, for each dependency, it can be determined if sub-dependencies exist. Similarly, for each sub-dependency, it can be determined if further sub-dependencies exist and so forth. By traversing the hierarchy of dependencies, a comprehensive listing of required dependencies can be generated.  
         [0038]     In block  330 , all required dependencies (whether usage based, containment based, or equivalence based) can be located in the target platform. Additionally, any components which are noted within the target specific script to conflict with the installation of the application component can be confirmed to not to have been installed in the target platform. If in block  335  the required dependency relationship of the target specific script does not comport with the state of the target platform, any missing dependencies can be loaded in block  340 . If in block  345  the required dependency relationship of the target specific script still does not comport with the state of the target platform, in block  365  a failure notification can be generated and the process can end in block  370 . Otherwise, in block  350  the application component can be installed and in block  355  the installation of the components can be written to the registry. Finally, in block  360  a success notification can be generated and the process can terminate in block  370 .  
         [0039]     The present invention can be realized in hardware, software, or a combination of hardware and software. An implementation of the method and system of the present invention can be realized in a centralized fashion in one computer system, or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system, or other apparatus adapted for carrying out the methods described herein, is suited to perform the functions described herein.  
         [0040]     A typical combination of hardware and software could be a general purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. The present invention can also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which, when loaded in a computer system is able to carry out these methods.  
         [0041]     Computer program or application in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following a) conversion to another language, code or notation; b) reproduction in a different material form. Significantly, this invention can be embodied in other specific forms without departing from the spirit or essential attributes thereof, and accordingly, reference should be had to the following claims, rather than to the foregoing specification, as indicating the scope of the invention.