Abstract:
One aspect of the present invention can include a system, a method, a computer program product and an apparatus for federating policies from multiple policy providers. The aspect can identify a set of distinct policy providers, each maintaining at least one policy related to a service or a resource. A federated policy exchange service can be established that has a policy provider plug-in for each of the distinct policy providers. The federated policy exchange service can receive requests for policies from a set of policy requesters. Each request can include a resource_id or a service_id used to uniquely identify the service or resource. The federated policy exchange service can dynamically connect to a set of the policy providers to determine policies applicable to each request. For each request, results from the policy providers can be received and processed to generate a response. The federated policy exchange service can provide the response to each policy requestor responsive in response to each response.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to Web Service policies, and more particularly, to federating policies from multiple policy providers. 
     Web services are self-contained pieces of programmatic logic that communicate externally through XML based messaging, typically in conformance with a SOAP protocol. Web services are often defined through languages such as WSDL and are registered within one or more registries, such as a Universal Description, Discovery, and Integration (UDDI) registry. Every Web service is associated with one or more policies, which can be defined as a set of assertions (rules, requirements, obligations) that define properties of a contract of a Web service based communication. Web service policies define an interface for the Web services (typically defined using WSDL in a UDDI directory), define a format of a message payloads of the Web service (typically defined using WSDL in a UDDI directory), and/or define other behavior requirements of the Web service. Some of the behavior requirements (policies) of Web service relate to ensuring an established Quality of Service (QoS), others relate to monitoring the Web service performance, others to security considerations for the Web service, still others relate to defining and enforcing business goals and/or logic. 
     Representational state transfer (REST) is a style of software architecture for distributed hypermedia systems such as the World Wide Web. The terms “representational state transfer” and “REST” were introduced in 2000 in the doctoral dissertation of Roy Fielding, one of the principal authors of the Hypertext Transfer Protocol (HTTP) specification. The terms have since come into widespread use in the networking community. REST strictly refers to a collection of network architecture principles which outline how resources are defined and addressed. The term is often used in a looser sense to describe any simple interface which transmits domain-specific data over HTTP without an additional messaging layer such as SOAP or session tracking via HTTP cookies. 
     Policy enforcement/access points exist in a runtime environment that are configured to support Web services. These enforcement or access points are nodes of a runtime environment which are configured to ascertain specifics of one or more Web service policies, to apply suitable programmatic logic to enforce the policy, and/or to enact a programmatic action based upon one or more defined policies. 
     A challenge with Web service policies is that there are often many different policy providing domains (security, routing, monitoring, etc.), and not all of these domains are centralized. For example, access control policies can be contained in an access manager, such as IBM TIVOLI ACCESS MANAGER. Routing policies can be defined within a registry repository, such as WEBSPHERE SERVICE REGISTRY AND REPOSITORY (WRSS). Monitoring policies can be contained in an application management component, such as IBM TIVOLI COMPOSITE APPLICATION MANAGEMENT (ITCAM). For an enforcement point and/or access point to be aware of all policies to be applied to a Web service, multiple policy providers must be queried. 
     Numerous efforts for establishing metadata repositories (e.g., WSRR, TIVOLI CHANGE AND CONFIGURATION MANAGEMENT DATABASE (CCMDB), TIVOLI FEDERATED IDENTITY MANAGER (TFIM), etc.) have been attempted and are in existence. While these efforts have each yielded beneficial results in many ways, none have resolved problems with effectively federating policies. One reason for this is that previous efforts for federating policies assume that there is a single point/location/registry where all policies are registered. Each currently existing policy provider (WSRR, CCMDB, TFIM, etc.), however, addresses numerous concerns relating to Web services in different ways, which to this point has prevented policies from being centrally registered. These specific concerns are important for the various components to perform their individual roles (i.e., security for TAM, monitoring for ITCAM, etc.). 
     It should be noted that the policy providers detailed above are all components of a common architecture or solution for Web services (e.g., are IBM-centric components). Other architectures exist, each having an architecture specific set of policy providers. Additionally, policies are currently defined by policy providers using numerous largely incompatible languages; some having an approach of defining policies as instances (e.g., Web Services Policy Language); others having an approach of expressing policies as classes (OWL-DL). In light of the above, no unification of Web service policies into a single “master” repository is expected in the near future, if ever. At the same time, no known solution exists for unifying or federating policy data from multiple policy providers. 
       FIG. 1  (prior art) illustrates a current situation regarding Web services and their policies. At present access/enforcement points  112  can receive services/resource  122  from a resource server  120 . An access point  112  can consist of one or more users  114  interacting with a client  116  that utilizes the service/resource  122 . An enforcement point  112  can include a software agent executing on a computing device ( 116 ) that utilizes the service/resource  122 . Each of the resources/services  122  have a number of associated policies  126  stored in different data stores  128 . Any entity/data store  128  that stores resource policies  126  can be generically referred to as a policy provider. The policy providers  128 , resource server(s)  120 , and access/enforcement points  112  can each be connected via a network  118 . Resource servers  120 , access points  112 , policy enforcement points each have to query multiple different policy providers  128  to determine relevant policies  126  applicable to a given service/resource, which results in synchronization problems and inconsistent policy application as previously noted. 
     BRIEF SUMMARY OF THE INVENTION 
     One aspect of the present invention can include a system, a method, a computer program product and an apparatus for federating policies from multiple policy providers. The aspect can identify a set of distinct policy providers, each maintaining at least one policy related a Web service or a resource. A federated policy exchange service can be established that has a policy provider plug-in for each of the distinct policy providers. The federated policy exchange service can receive requests for policies from a set of policy requesters. Each request can include a resource_id or a service_id used to uniquely identify the service or resource. The federated policy exchange service can dynamically connect to a set of the policy providers to determine policies applicable to each request. For each request, results from the policy providers can be received and processed to generate a response. The federated policy exchange service can provide the response to each policy requestor responsive in response to each response. 
     Another aspect of the present invention can include a system for federating Web service policies. The system can include a set of policy providers, a federated policy server, and a set of policy requesters. The set of policy providers can each manage at least one policy for a Web service. The federated policy server can include a set of provider interface modules, one for interfacing with each of the policy providers. The federated policy server can accept policy requests, can lookup matching policies for the requests within policy stores maintained by the plurality of policy providers, and can provide responses to the policy requests based upon lookup results. The policy requesters can utilize the federated policy server for policies related to at least one Web service. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  (Prior art) illustrates a runtime environment in which Web service policies are managed and utilized. 
         FIG. 2  illustrates a runtime environment in which Web service policies are federated in accordance with an embodiment of the inventive arrangements disclosed herein. 
         FIG. 3  illustrates a federated policy exchange service in accordance with an embodiment of the inventive arrangements disclosed herein. 
         FIG. 4  is a schematic diagram of a system for a federated policy server that provides requesters Web service policies, which are registered within multiple discrete repositories in accordance with an embodiment of the inventive arrangements disclosed herein. 
         FIG. 5  is a schematic diagram of an architecture for federating policy data registered and maintained within different repositories in accordance with an embodiment of the inventive arrangements disclosed herein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a solution where a federated policy server  230  federates policy  226  data from multiple policy providers  228 , as shown in  FIG. 2 . The server  230  can be connected to one or more resource servers  220  and one or more access/enforcement points  212  via a network  218  in runtime environment  210 . Access/enforcement points  212  and resource servers  220  can query the federated policy server  230  and receive all policies  232  applicable to a given service/resource  222 . This negates a need to individually query multiple policy providers  228  and solves issues associated with policy synchronization and inconsistent policy enforcement. 
     The federation policy server  230  can federate policies  226 , as shown in  FIG. 3 . That is, the federation policy server  230  can execute a federated policy exchange service  310 , which provides a policy provider lookup service based upon a unique service/resource identifier. The federated policy exchange service  310  can include multiple policy provider plug-ins  312 . Each plug-in  312  can permit the federated policy change service to exchanged information with a plug-in  312  specific provider services  314 , which can be repository instances. Each of the provider services  314  can be linked to an underlying storage repository  316  within which policy information  318  is stored. The plug-in  312  can include conversion, reformatting, transcending instructions that permit the federated policy exchange service  310  to handle the policies in a unified manner. 
     The present invention may be embodied as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, the present invention may take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. 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 apparatus that can store the program for use by or in connection with the instruction execution system, apparatus, or device. 
     Any suitable computer usable or computer readable medium may be utilized. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. 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), an erasable programmable read-only memory (EPROM or Flash memory, 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. 
     Computer program code for carrying out operations of the present invention may be written in an object oriented programming language such as Java, Smalltalk, C++ or the like. However, the computer program code for carrying out operations of the present invention may also be written in conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     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 present invention is described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
       FIG. 4  is a schematic diagram of a system for a federated policy server  420  that provides requestors  410  Web service policies, which are registered within multiple discrete repositories in accordance with an embodiment of the inventive arrangements disclosed herein. The system  400  of  FIG. 4  is consistent with expressions of the invention presented in  FIG. 2  and  FIG. 3 . 
     In system  400 , the federated policy server  420  can provide a policy exchange service  422 , which requestors  410  can utilize to determine any policy of a Web service, resource, or other object, regardless of policy domain  450 . Federated policy server  420  can include multiple provider interface modules  426 . Each module  426  can permit the server  420  to interface with a specific policy provider  430 . The module  426  can convert format of policy  444  information provided by a provider  430  to a standardized one used by the policy server  420 . In one embodiment, the federated policy server  420  need not locally (using data store  428 ) maintain policy data, but can dynamically acquire it from remotely located data stores  432  maintained by policy providers  430 . In another embodiment, the server  420  can locally maintain a portion of policy information in a local data store  428 . 
     Any data acquisition technology (e.g., subscription, polling, etc.) can be used when exchanging information  442 ,  444  between the federation policy server  420  and the policy providers  430  and when exchanging information  440 ,  446  between the policy requester  410  and the server  420 . In a typical transaction, a policy requester  410  can convey a policy request  440  to the federated policy server  420 . The request  440  can request one or more policies (up to all) of a Web service, resource, or other object. The policy server  420  can submit suitably formatted requests  442  to one or more policy providers  430  resulting in responses  444 . These responses  444  are processed by the federation component  424  and converted into response  446 , which is sent to the policy requester  410 . Importantly, the policy requester  410  can submit any type of policy request  440  to the federated policy server  420  without needing to know which policy provider(s)  430  maintains policies of the requested type. In one embodiment, a published policy exchange service  422  can be used to interface with the policy requestors  410 . 
     As used herein, a policy is an interface that defines a condition applied to a Web service, resource, or information. Policies can include behavioral requirements, format requirements, Quality of Service (QoS) requirements, business requirements, security requirements, monitoring requirements, and the like. 
     The policy provider  430  is an entity that exposes one or more policies related to a Web service, resource, or information. For example, policy providers  430  can include a WEBSPHERE APPLICATION SERVER (WAS), a DATAPOWER server, a TIVOLI ACCESS MANAGER (TAM) server, a .NET server, IBM TIVOLI COMPOSITE APPLICATION MANAGEMENT (ITCAM) server, an IBM Tivoli Management Framework (TFM) component, a WEBSPHERE SERVICE REGISTRY AND REPOSITORY (WRSS), a TIVOLI CHANGE AND CONFIGURATION MANAGEMENT DATABASE (CCMDB), a Universal Description, Discovery, and Integration (UDDI) registry, and the like. 
     A policy domain  450  can contains policy sets, management classes, and copy groups. Policy domains  450  are enforced by numerous servers, such as WS-security server. The federated policy server  420  can interact across different policy domains  450 . 
     A policy requestor  410  can be any entity that request a policy from the federated policy server  420 . For example, a policy requestor  410  can include a policy point, which can be a point in a service oriented architecture (SOA) that enforces, monitors, and/or takes other programmatic action involving a resource/service based upon a preexisting policy. The policy requester  410  can include a management system, a service registry, and/or an access point utilizing a Web service. 
     Data exchanged  440 - 446  in system  400  can be conveyed over a network. The network can include any hardware, software, and firmware necessary to convey data encoded within carrier waves. Data can be contained within analog or digital signals and conveyed though data or voice channels. The networks can include local components and data pathways necessary for communications to be exchanged among computing device components and between integrated device components and peripheral devices. The networks can also include network equipment, such as routers, data lines, hubs, and intermediary servers which together form a data network. The networks can further include circuit-based communication components and mobile communication components, such as telephony switches, modems, cellular communication towers, and the like. Additionally, the networks can include line based and/or wireless communication pathways. 
     The data stores  428 ,  432  can be a physical or virtual storage repository configured to store digital information. The data stores  428 ,  432  can be physically implemented within any type of hardware including, but not limited to, a magnetic disk, an optical disk, a semiconductor memory, a digitally encoded plastic memory, a holographic memory, or any other recording medium. Each of data stores  428 ,  432  can be a stand-alone storage unit as well as a storage unit formed from one or more physical devices. Additionally, information can be stored within the data stores  428 ,  432  in a variety of manners. For example, information can be stored within a database structure or can be stored within one or more files of a file storage system, where each file may or may not be indexed for information searching purposes. Further, the data stores  428 ,  432  can optionally utilize one or more encryption mechanisms to protect stored information from unauthorized access. 
       FIG. 5  is a schematic diagram of an architecture  500  for federating policy data registered and maintained within different repositories in accordance with an embodiment of the inventive arrangements disclosed herein. 
     In architecture  500 , service definition/metadata  580  regarding policies can be federated using a set of policy management tools  540 . The policy data  580  can be acquired from one or more development environment  510 , from one or more deployment environments  520 , and/or from a set of service registries and repositories  530 . 
     The policy management tools  540  can federate data  580  from different policy sources  510 ,  520 ,  530  regardless of platform specific considerations in a platform independent manner. For example the development environment  510  can be a JEER based  512 , a .NET  513  based, or other  514  computing environment and still be supported by tools  540 . Similarly, different types of deployment environments  520 , such as a WAS  522  environment, a DATAPOWER  523  environment a TAM  524  environment, a .NET environment  525 , and any other deployment environment  526 , can be supported. Policy data  580  registered within different repositories, such as WRSS  532 , CCMDB  533 , and a Universal Description, Discovery, and Integration (UDDI) registry  534 , can also be handled. 
     The policy management tools  540  can include policy authoring tools  541 , service discovery tools  542 , change management tools  543 , policy repository tools  544 , evaluation and analysis tools  545 , policy distribution tools  546 , monitoring and reporting tools  547 , service management tools  528 , and the like. One or more federated policy servers (e.g., server  420 ) can provide the tools  540 . 
     Policies can be published  582  to a policy exchange service  550 . In one embodiment, the policy exchange service  550  can be a Web service that federates policy data about other Web services. Service  550  can be utilized to retrieve and/or distribute policies  548  to service registries  560  (e.g., WARS, CCMDB, etc.), to management systems  562  (e.g., TAM, ITCAM, etc.), and to policy points  564 . 
     A policy point  564  can include a policy enforcement point (PEP), a policy decision point (PEP), and any other point that desires to access a Web service policy. Each policy provided by the service  550  can include a policy transformation  570  and a raw policy  572 . For example, the raw policy  572  can be a DATAPOWER  523  policy from a deployment environment  520  where the policy transformation  570  is specific to DATAPOWER and implemented using a DATAPOWER specific interface module (e.g., module  426  from system  400 ). In another example, the raw policy  572  can be a WAS policy having a WAS specific transformation  570  applied to it. Still another policy provided to a point  564  can be a TAM policy (raw policy  572 ) having a TAM specific transformation  570 . 
     The diagrams in  FIGS. 2-5  illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but 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 without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and 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.