Method and apparatus for remote network management

Field of Invention

0001This invention generally relates to a software system and method for remote administration and management of a computer network.

Background of the Invention

0002It is now generally recognized in the computer software industry that multi-tier distributed server architectures confer a variety of benefits, including increased capacity, throughput, fault tolerance, scalability, and reliability. However, due to their decentralized nature, such architectures pose particular difficulties in the area of application management and administration.

0003One of the chief difficulties involved with such systems is their cost of ownership. When deployed in production settings, software systems based on distributed server architectures typically incur a high cost of ownership, including costs incurred from the need to employ and train a large number of administrative and maintenance personnel as well as costs incurred from the difficulty of isolating and fixing problems. Cost of ownership is further multiplied in the case of software systems that are distributed across multiple geographic locations.

0004This high cost of ownership constrains the market for commercial software products based on distributed server architectures. Minimizing the cost of ownership significantly expands the potential market for these software products and allows more organizations to take advantage of the benefits conferred by such products.

0005A special type of software program is a background process that may be started automatically by an operating system at startup. For example, background processes that run on certain Microsoft operating systems such as Windows NT and Windows 2000 are termed "services." Generally, services are a background process which is loaded by part of the operating system kernel, typically at startup or bootup, prior to any user log-ins. Services differ from other software programs in that they can be configured to start automatically when the operating system starts, thus simplifying administration. In addition; they generally do not require a logged-on user in order to run and they run in their own security context. Services typically are accessed by an operating system directly, and thus have no local user interface, although they can usually be launched manually by a user through a service control utility, e.g., a "control panel" or the like. Other operating systems, such as UNIX, have similar background processes, typically termed daemons, although for purposes of the present invention these background processes may be referred to as generally as services.

0006A software system based on distributed services, i.e., services existing on various remote computers, can take advantage of the characteristics of services to reduce the cost of ownership. However, because services have no local user interface; such a software system typically requires a remote administrative user interface to manage the distributed services. It would be desirable to enable the administration of such a software system either from a single computer at a central location or from multiple computers at different locations, depending on the deployment scenario and the requirements of the customer.

0007Existing network management standards, such as the SNMP and CMIP standards, have focused on management of the underlying network and associated devices rather than management of heterogeneous networked software applications. SNMP, for example, supports getting and setting properties on user-definable managed objects but offers no direct support for parameterized method execution. Other management standards, such as WBEM, can accommodate services as managed objects, but the relevant provided interfaces are limited to the least common subset of service properties and methods and are not easily extensible to accommodate rich service-specific property sets.

0008While certain existing network management approaches can theoretically support rich service-specific property sets through the definition of custom classes or interfaces, such approaches generally suffer from one or more of the following limitations: There is typically no easy-to-use programming interface to support rapid application development the design and implementation of custom classes and interfaces is prohibitively difficult and labor-intensive, property sets are at best expressible simply as collections of name/value pairs and therefore cannot easily express rich structure, property sets are generally limited in size, custom classes and interfaces are generally not resilient to change in the underlying service property sets no mechanism is provided to control bandwidth by allowing a client administrative program to specify a subset of properties to retrieve, and/or no security mechanism is provided.

0009In some networked applications of the prior art, e.g. a front-end database management application, an application may communicate directly with managed network services. However, there are problems with such a design. For example, this design prohibits any viewing and setting of configuration information unless the managed services are active. This reliance on services being active is unacceptable, because typically services are heavyweight processes that often taken a long time to initialize and consume many system resources. In a distributed application it is not uncommon for the services on a particular remote machine to be inactive, which in such a design would prohibit the application of consistent configuration changes across similar services on several machines.

0010Generally, service properties and statistics are hierarchical and nontabular in structure and generally lack fixed dimensionality. Because the set of properties and statistics desired in network management communications, regarding both background process status and network performance parameters, are likely to change frequently in the future, preferably the design of a network management tool must be flexible and extensible. In addition, various data types pertinent to network administration and performance analysis must be supported, including strings, Boolean or dummy variables, date/time, and integrals. Incurring a network round trip for each read or write of an individual property or statistic is undesirable, because this may cause network administration to impose a significant load on the network. Similarly, it is desirable to be able to apply changes to service properties in bulk or batched fashion. Finally, it would be desirable that collections of properties and statistics should be accessible and navigable using a standardized or open technique rather than a proprietary one if possible.

0011It would be desirable to provide a network management tool for management of distributed services, providing for ease of administration for network systems with reduced cost of ownership, that does not suffer from the above limitations. In particular, in managing a distributed network, rather than being limited to getting and setting one property or statistic at a time, preferably a network management tool would act in a fashion to batch certain functions in order to conserve bandwidth when possible. Preferably, this network management tool will combine relative ease of client programming with extensibility, while minimizing network overhead and traffic.

0012It is at least theoretically possible to provide network administration tools utilizing COM interface properties, tabular reports, standard COM collection objects such as SAFEARRAYs, or custom marshalling. However, these potential methods violate the desired administration properties detailed above.

0013An Extensible Markup Language (XML, for extensible Markup Language) has been developed as a restricted form of the more cumbersome SGML (Standard Generalized Markup Language). Generally, XML describes a class of data objects, XML documents; which may be parsed by XML processors in remote locations in order that the remote application may access the structure and content of the XML document in a form meaningful to the application. The XML processor, following the XML, rules about what information from the XML document it must provide to the application, sends relevant data and instructions to the remote application. In contrast to HTML, a different SGML derivative, XML provides a facility for developers to provide their own XML markup and tag types which may be useful in providing information to a remote application. This application, via a XML processor, may receive instructions or data contained in an XML document, and may return data or instructions in a similar way. While XML, documents will naturally be larger than application-specific or native binary files sent directly between applications, they are language independent, and as text files, are easier to maintain and debug than corresponding binary "bitstream" transmissions.

0014<patcit id="pcit0001" dnum="WO9957649A"><text>WO 99/57649</text></patcit> discloses a system and method for controlling a plurality of automatic data collection (ADC) device platforms. In the invention, a remote computing system having browsing software adapted for receiving and sending Hypertext Mark-Up Language (HTML) documents, Dynamic Hypertext Mark-Up Language (DHTML) documents, and Extensible Mark-Up Language (XML) documents over the World Wide Web communicates with a network of ADC platform devices. A Simple Network Management Protocol (SNMP) master agent at the ADC device platform communicates with the remote computing system and a Hypertext Transfer Protocol (HTTP) server sends HTML documents, DHTML documents, and XML documents to the remote computing system over the World Wide Web. A translator translates SNMP-formatted data sent to the attached ADC devices into a format suitable for reception by each ADC device. Another translator translates data received from the ADC devices into the SNMP format. The SNMP master agent communicates with the remote computing system using the TCP protocol, the UDP/IP protocol, and the UDP+ protocol. The ADC platform device may utilize a wireless communications system for communicating with the remote computing system.

0015<patcit id="pcit0002" dnum="EP0909058A"><text>EP-A-0 909 058</text></patcit> discloses a generic management framework for a network management system which enables management services and management agents to be added in use as required. Management services can be loaded or plugged into the framework dynamically. As a result a management structure can be provided which is scalable and dynamic and can evolve as requirements change. Management information is modeled as management beans. Network management adaptors can also be added as required to the framework to support protocols such as HTTP, SSL, RMI, SNMP. Remote applications can thereby control the management beans remotely through different protocols.

0016An article by <nplcit id="ncit0001" npl-type="s"><text>LAVALLEE B: "Improving power supply reliability at a reduced cost using test automation and data management TELECOMMUNICATIONS ENERGY CONFERENCE, 1995. INTELEC '95., 17TH INTERNATIONAL THE HAGUE, NETHERLANDS 29 OCT.1 NOV. 1995, NEW YORK, NY, USA,IEEE, US, 29 October 1995, pages 132-136, XP010161223 ISBN: 978-0-7803-2750-4</text></nplcit> describes a testware package in which, in order to get the most performance possible and create reusable software code, c + + was used to take advantage of it's object-oriented programming (OOP) capabilities. Library of classes were written to communicate with internal computer data acquisition boards and "the various ATE test instruments. These libraries of classes make full use of inheritance, virtual functions, and polymorphism in order to" create flexible reusable software code while remaining very robust in performance. OOP allows for the creation of derived classes based upon the existence of proven base classes. Thus, existing pieces of time-proven software code is consistently built upon which minimizes the chance for error while dramatically reducing the software development cycle.

0017The present invention is as claimed in the claims.

Summary of the Invention

0018An object of the present invention is to provide an extensible framework for the remote management of software systems, particularly distributed services. In one embodiment of the present invention, Management and administrative functionality is provided that includes a facility for remotely ascertaining and modifying the status of the distributed services comprising the managed software system, remotely ascertaining the relationship among these services, remotely ascertaining and configuring the values of various groups of service properties that may either be shared among multiple services or specific to individual services, remotely obtaining various service statistics that may either be shared among multiple services or specific to individual services, and remotely obtaining version information This version information and other distributed network information, may pertain either to specific embodiments of the present invention and to individual managed services. The present invention may be used in various networked enterprise applications, such as data processing or work routing applications.

0019In a preferred embodiment of a software component framework according to the subject invention, a distributed agent framework is implemented that may be updated in accordance with modifications and enhancements of the services that make up the managed application overseeing the distributed agents. In addition, it is preferable to provide an environment or framework in which client management applications may be composed which reflect the full capacity and structure of the various properties and statistics associated with the diverse managed services. This software component framework for updating and managing remote network services is implemented via XML.

0020Furthermore, in a preferred embodiment of the subj ect invention, bulk transfer of properties and statistics may be effected, in order to 'batch' network management tasks, and thus conserve bandwidth and reduce overhead. It will also be preferred in implementing the subject invention that, in order to further conserve network bandwidth by eliminating unnecessary data communications, a client application may specify a subset of properties or statistics to retrieve on a given call.

0021In addition, a preferred embodiment of the invention will provide automated or otherwise facilitated client programming which avoids the need for bit stream parsing or proprietary encoding at the client level. For example, this automation may be implemented using COM automation. COM (Component Object Model) components are reusable and generalized modules of code which define an language-independent interface for certain software functions. General information about the implementation of COM objects may be obtained from the Microsoft Corporation of Redmond, Washington. Other reusable software interfaces which provide encapsulation, particularly object-oriented interfaces, may also be utilized in order to provide client-level interfaces with the network management Software according to the present invention. In a preferred embodiment of the invention, these reusable software interfaces will be language independent. For example, interfaces provided under the CORBA (Common Object Request Broker Architecture) are believed to provide suitable interface components for the present invention. For example, suitable interfaces may be implemented in, and used by, Java, Visual Basic, C++, for example, or may be found in Enterprise Java Beans libraries or COM libraries.

0022In order to achieve the objectives of a preferred embodiment as detailed above, a SGML-derivative maybe utilized to implement the subject invention. SGML will generally prove unsatisfactory for implementing the present invention, due to its relatively slow and unwieldy structure, and poor transmission characteristics. XML is a derivative of SGML which provides a lightweight markup language suitable for network transmission Instructions and data are embedded into XML documents and transmitted to remote servers or other network components for parsing and sending to server-side and other applications remote from the user or network administrator. For example, the XML document may contain embedded instructions to a NT service. In a preferred embodiment, these instructions will be polymorphic, i.e., they may consist of managed sets of network properties and statistics which may vary according to context, but will not be rejected by the target remote application as erroneous.

0023In a further preferred embodiment of the subject invention, distributed agents may be utilized in order to accommodate diverse polymorphic managed services. These agents, actually software routines, may be dispatched to dynamically discover, for example, changes to network topology or changes to the topology of the distributed application. Because these agents may discover such configuration properties "on the fly," the network need not be taken down for analysis, and network performance is not impacted in the course of measuring the performance. In addition, the distributed agents enable remote viewing of configuration properties associated with diverse polymorphic background processes, services, or applications, even if those processes are inactive. The agent entities pass the acquired statistics and properties via XML documents to the client Management Component application, as detailed elsewhere in this Specification.

0024These agents are capable of managing polymorphic services, i.e, services which are derived from or instantiated from a common base or generic type. These services which are instantiated from a generic type will share common functions or methods with the base services, and may accept arguments of a similar data type, or may accept alternative data type arguments. Polymorphism is a software property which is important in providing for reusable code. In other words, polymorphism allows operations to be applied over various data types.

0025It will also be preferred that such agents will be extensible to support new or modified services, and will be able to support many different distributed application and network topologies. In this regard, these distributed agents will preferably be able to dynamically discover changes to the topology of a distributed application being considered or monitored. It will also be preferred to enable remote viewing and modification by a human network administrator, or to allow modification of configuration properties associated with diverse polymorphic services by automated network management software. This preferred embodiment enables the remote viewing and/or modification of configuration properties associated with these diverse polymorphic services even when those services are inactive. In this embodiment, the problems, a central point of failure, and processing bottlenecks are both avoided. Both of these problems are major sources of network performance deficiencies. A further advantage of the present invention is that a high degree of scalability may be achieved.

0026In a preferred embodiment, the present invention provides further increases in the efficiency of network administration and performance criteria by the application of automated component interfaces, such as COM components, which preferably act as a type of remote agent, distributed among and resident on remote server and network resources, with access to statistical and state information regarding those resources.

0027Without providing for a distributed agent layer, front-end management applications would be required to communicate directly with the managed services. In addition to being substantially more brittle and less extensible than the present invention, this design would prohibit any viewing and setting of configuration information unless the managed services are active. This reliance on active services is highly unattractive, because services are heavyweight processes that often taken a long time to initialize and consume many system resources. In a distributed application it is not uncommon for the services on a particular machine to be inactive, which would prohibit the application of consistent configuration changes across similar services on several machines. Lightweight distributed agents facilitate such scenarios because they are quick and inexpensive, in terms of computing overhead, to activate for such purposes.

0028Management components according to an embodiment of the present invention operate as a type of software agent that undertake several distributed management and monitoring tasks. While the management components of the present invention will typically neither autonomous nor asynchronous, the management components of the present invention may be regarded as "agents" in that they are independent distributed software objects that mediate the interaction between a remote user and the services or other remote processes being managed. The management components also communicate with each other to accomplish the management task. In one embodiment of the present invention the management components are designed, as a security precaution, so as to be incapable of autonomously migrating across networked hosts. In other words, the management components may be implemented so as to lack "mobility."

0029Unlike distributed systems that do not use independent software objects to mediate the interaction between the user and the managed services, the management components of an embodiment of the present invention mediate the interaction between user and service, and also communications with other management components.

0030In a preferred embodiment of the present invention, the network management system is developed using encapsulated interface objects, such as COM components, or certain Enterprise Java Beans classes. These interface objects or classes may be defined by standards such as CORBA, or they may be defined under proprietary systems. Certain of these object components may be found in pre-existing component or object libraries which are widely available from a variety of vendors, including Microsoft Corporation, of Redmond, Washington, or Sun Microsystems, Inc., of Palo Alto, California.

0031In a preferred embodiment of the subject invention, automation interfaces, such as COM automation interfaces, are implemented as server-side components. In this way, the present invention may support the easy and rapid development of front-end management applications using a wide variety of programming languages and techniques, including scripting languages such as VBScript and JavaScript in addition to languages such as Visual Basic, Java, and C++, or any language which may access the encapsulated automation interface to be used. For example, in an embodiment of the subject invention in which COM components are used, even an Excel brand spreadsheet could be used to script a front-end management application for the remote management component.

0032In an embodiment of the present application in which the COM automation interfaces are used, a wide range of possible client applications may be supported. These include, but are not limited to, web browser-based management interfaces to standalone 'thick' Windows programs to Microsoft Management Console 'snap-ins'. In this embodiment of the present invention, new client applications may be developed without having to specifically modify the services comprising the managed application to support any particular type of management client program. Encapsulated reusable interfaced code, such as the COM automation interfaces, may be expected to support easy integration of the management components of the present invention. Such encapsulated code serves particularly to provide managed application of external systems, particularly external systems management infrastructures.

0033In the present invention, the SGMM-derived markup language XML used to provide remote retrieval and configuration of property sets in a bulk or batch fashion, thus minimizing network round trips and in turn conserving network bandwidth. It has been found that XML provides a suitable format to represent service properties and statistics.

0034The present invention also allows remote administrative client programs to specify one or more particular subsets of available properties or statistics to retrieve for or form a managed service, thereby further conserving network bandwidth. Rather than imposing a single limiting structure for properties and statistics, the present invention can accommodate service-specific sets of properties or statistics having any organizational structure, including complex hierarchical structures, while still maintaining ease of programming for remote administrative client programs. Another advantage of the present invention is that it imposes no size limit on sets of properties or statistics.

0035An advantage of the preferred embodiment of the present invention is that properties of the services comprising the managed software system can be ascertained and configured regardless of whether these services are currently running.

0036Another advantage of the present invention is that it is easily extensible to support an unlimited variety of services, each of which may expose or obtain a unique set of properties and statistics. It also adapts easily to modifications of the managed services, including modifications to the set of properties and statistics exposed by a managed service.

0037Furthermore, a typical embodiment of the present invention scales extremely well to accommodate managed systems of unlimited size and scope without imposing any processing bottleneck proportional to the size or scope of the managed system. Another advantage is that it imposes no single points of failure upon the managed system.

0038Another advantage of the present invention is that it provides an easy-to-use programming interface to facilitate rapid development of remote administrative client programs. It also facilitates integration with external systems other than the managed system.

0039Another advantage of the present invention is that it supports a variety of remote administrative client programs, including both traditional 'thick' client programs as well as 'thin' web browser-based client programs. Furthermore, the invention supports various type of remote administrative client programs running concurrently against the same managed system.

0040In a representative implementation of the present invention, remote administrative client programs may easily and dynamically discover the set of services comprising the managed distributed software application and the precise distribution of these services across computers in the application domain, even in the event that one or more of these computers is inactive. Because the present invention provides a mechanism to determine this information dynamically, remote administrative client programs do not have to contain sophisticated programming logic to determine this information themselves or to persist this information across sessions, and remote administrative client programs can dynamically discover changes to the topology of the distributed application without employing any special programming logic for this purpose.

0041In a preferred embodiment of the present invention, a high level of security is provided by the use of role-based method-level access control.

0042While, in a preferred embodiment of the subject invention, the invention is implemented as part of a network operating system, for example, or enterprise application such as a workflow management application, the network management tools of the present invention may also be implemented as a stand-alone implementation.

Brief Description of the Drawings

0043<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a schematic diagram of the architectural environment of an embodiment of the invention.</li><li><figref idref="f0002">Figure 2</figref> is a class diagram of an embodiment of the present invention.</li><li><figref idref="f0004">Figure 3</figref> is a schematic diagram of an embodiment of the present invention installed at a single location.</li><li><figref idref="f0007">Figure 4</figref> is a schematic diagram of an embodiment of the present invention across many computers at multiple locations.</li></ul>

Software Appendices

0044Software Appendices A-G are attached to this specification, and are hereby incorporated by reference herein.

Detailed Description of the Invention

0045The following terms are used in this description of a preferred embodiment of the invention, generally, and with regard to an embodiment of the subject invention adapted to remotely administer a network running on a Microsoft operating system, such as Windows NT: <dl id="dl0001" compact="compact"><dt>COM</dt><dd>Microsoft Component Object Model</dd><dt>DCOM</dt><dd>Microsoft Distributed Component Object Model</dd><dt>mL</dt><dd>Interface Definition Language</dd><dt>MC</dt><dd>Software Management Components according to the present invention</dd><dt>MMC</dt><dd>Microsoft Management Console</dd><dt>MTS</dt><dd>Microsoft Transaction Server; also termed COM+ in regards to the Windows 2000 operating system</dd><dt>MTS Explorer</dt><dd>Microsoft Transaction Server Explorer; Component Services Applet on Windows 2000</dd><dt>SCM</dt><dd>Service Control Manager</dd></dl><ul id="ul0002" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> depicts a simplified view of the architectural context 110 of a preferred embodiment of the invention (the Software Management Components) in relation to a managed software system made up of distributed services and a remote administrative client program. This implementation of the present invention is adapted for a Windows operating system, or other operating system utilizing COM encapsulated interface components although other encapsulated interface objects may also be used. In this implementation, COM components 112, or alternative encapsulated interfaces which are language-independent, serve as interfaces modules between the administrative client program 114, and various distributed background processes 116 running on remote network resources, e.g., servers. The various COM components of the Management Component level are shown as standard COM notation components 112 within the Management Component level of the architecture 118.</li><li><figref idref="f0002">Figure 2</figref> depicts a class diagram 130 showing interface methods, interface properties, classes, associations, and inheritance relationships of an embodiment of the present invention, which may be implemented, for example, as COM interfaces 112 of <figref idref="f0001">Figure 1</figref>. <figref idref="f0002">Figure 2</figref> identifies the software components comprising a preferred embodiment of the invention along with the interfaces implemented by said components. The diagram uses conventions adapted from the Unified Modeling Language (UML) to depict interface methods, interface properties, classes, associations, and inheritance relationships. These components, as implemented in Visual Basics as an example, are provided in Source Code Appendix A.</li><li><figref idref="f0004">Figure 3</figref> depicts a schematic diagram 150 of a deployment of a preferred embodiment of the invention across several computers at a single location, showing specific COM interfaces which may be implemented in both a domain controller 152 and in a child server 154. This diagram implements the component interfaces depicted in class diagram 130 of <figref idref="f0002">Figure 2</figref>, specifically as COM interfaces 156. These COM interfaces 156 may monitor and in most cases control corresponding service elements 158 of a specific managed system. These interfaces 156 operate as "agents" on the remote network resources, within the definition of "agent" discussed previously. Also depicted are two specific remote administrative client programs MMC client 160 and a typical HTTP client 162. The MMC (Microsoft Management Console) client 160 and HTTP client 162 access the domain controller and child server COM interfaces 156 via MTS server 164, according to the DCOM (Distributed Component Object Model) security interface, used to authenticate clients, and also capable of implementing encryption across transmission paths. Alternatively, a security protocol such as Kerberos could be used to protect network communications along pathways 166 and provide authentication. Alternatively, MTS authentication may be implemented for security.</li><li><figref idref="f0007">Figure 4</figref> depicts a schematic representation of a typical deployment of a preferred embodiment of the invention across many computers at multiple locations. This diagram depicts a network system 170, consisting of interface modules such as encapsulated reusable COM interface modules 156, the modules corresponding generally to the interface components depicted in the class diagram 130 of <figref idref="f0002">Figure 2</figref>, as well as the corresponding service elements of a specific managed system and two specific remote administrative client programs.</li></ul>

0046The Management Components of the present invention are, by way of example, implemented as shown in <figref idref="f0007">Figure 4</figref> as a single in-process interfaced encapsulated component, e.g., a COM component. In a preferred embodiment, in which the management components are implemented as a COM component, the management component implements classes that are designed to run in Microsoft Transaction Server (MTS). For example, Management Component objects according to a preferred embodiment may reside on ENTERPRISE APPLICATION servers, i.e., servers running an enterprise application on the Windows NT brand platform. Management Component clients 160 typically access Management Component objects 172 remotely via to a distributed encapsulated interfaced component or class implemented server, e.g., DCOM or via Microsoft MTS.

0047When implemented as a COM interface, the Management Components distributed object model preferably specifies several COM interfaces that are implemented by the Management Component COM classes. In order to support a wide variety of clients, the Management Component interfaces are exposed as COM dual interfaces, i.e. both as custom v-table interfaces and through a standard COM IDispatch interface.

0048Also in a preferred embodiment, and as depicted in the class diagram 130 of <figref idref="f0002">Figure 2</figref> one or more MCDomain or similar instances support each Application Domain, e.g, each ENTERPRISE APPLICATION domain. MCDomain instances may typically reside on the domain controller of the corresponding application domain, although other configurations are also possible, including instantiation of MCDomain objects for an application domain on machines other than the application domain controller; instantiation of MCDomain objects on multiple machines for a single application domain; or instantiation of MCDomain objects on the same machine for multiple application domains.

0049Preferably the MCServer class or equivalent will be installed on each application server that hosts at least one application service. Each application service installed on an application server additionally will preferably have the corresponding Management Components service class to be installed on that server. The Management Components are also extensible to support the management of third party services as described below.

0050Preferably, clients need only create and initialize an MCDomain or equivalent object for an application service domain to discover all the application servers in that domain. In a preferred embodiment, clients can directly create instances of any Management Components class as required.

0051The Management Components as described herein are extensible to support the management of third party background processes written for a particular operating system, for example, third-party Windows NT services. In order to integrate a third party service into the Management Components framework, a corresponding interface component, e.g., a COM component, must be provided that implements the IMCService or its equivalent interface, such as interface 132 of class diagram 130 of <figref idref="f0002">Figure 2</figref>. It will also typically be necessary to provide access to the interface by client components, for example, by adding appropriate values must be added to a registry key. This registry key may, in a Windows implementation of the subject invention, appear as HKEY_LOCAL_MACHINE\SOFTWARE\<Installed Enterprise Application>/Management Components\<Version>\Service Classes, or an equivalent. IMCService or equivalent interface pointers to registered third party service components would in this way be accessible to clients by their automatic inclusion in the IMCServer.Services or equivalent collection.

0052In an alternate embodiment of the subject invention, XML may be incorporated into the Management Components and extended to arrive at a consistent solution for version and inventory information, including aggregation of network or server properties or statistics. Preferably, the common <service> root element is used for all XML service properties and statistics, thus supporting several possible extensions to the current model. For example, in an alternate embodiment of the present invention, properties or statistics reports may be aggregated across several services. Alternatively, tags such as <server> and <domain> may be introduced to XML documents to aggregate properties or statistics across multiple servers and domains.

0053Virtually any XML design project necessitates a design decision regarding whether to use elements or attributes in implementing a XML document. An element is a section of an XML document defined by start- and end-tags (or an empty tag); while an attribute provides information about elements-an attribute is a property of an XML tag which is a named characteristic of the tag. In a preferred embodiment of the present invention, elements maybe used to represent anything ultimately intended for presentation to a user, while attributes may be used in support of programmatic parsing or in cases requiring unique identification of elements.

0054Also in a preferred embodiment of the present application, network performance statistical units relevant to network administration may be embedded into XML tag names, rather than representing units as XML attributes. It is believed that this aids in human reference and readability, simplifying code maintenance and debugging. For example, tag names according to one embodiment of the present invention may be <itemAge_days>, <pollInterval_seconds>, and <maxTxTime_msec>.

0055XML data types described in this section such as int, boolean, string, and dateTime are consistent with the data types supported by a standard XML parser application that may run on a server remotely, providing instructions and data to a remote server. In a preferred embodiment of the invention, wherein a standard markup language is used, e.g., in the case of XML, any standard XML parser, e.g. Microsoft's msxml.dll dynamic linked library file can be used to process the XML, consumed and emitted by the Management Components.

0056In one embodiment of the present invention, applicable to remote management of services, XML may be used to represent service properties. In this embodiment, some or all of the COM interface properties may be eliminated, implemented instead as XML properties accessible through a single generic COM interface property.

0057In a preferred embodiment of the subject invention, encapsulated reusable interfaces, for example, COM interface properties, may be used for properties and status that are potentially applicable to all background services. Preferably, a mark-up language, e.g., XML, may be used for properties or statistics that are specific to one or a very few background properties, such as NT services.

0058In an embodiment of the subject invention in which XML is incorporated into the Management Components, it is thought to be preferable to use a common <service> root element for all markup language, e.g. XML, service properties and statistics. This structure supports several possible extensions to the current model. In order to further reduce network overhead and traffic, it may also prove desirable to aggregate properties or statistics reports across several services. In one embodiment of the present invention, this may be done by introducing tags such as <server> and <domain> into the markup language code, in order to aggregate properties or statistics across multiple servers and domains.

0059In a preferred embodiment of the subject invention, markup version information, e.g. XML version information may be derived from a software Management Component. The availability of version information is anticipated to aid in software maintenance and debugging, as well as future extensibility.

0060XML service properties will preferably be readable regardless of whether the corresponding service is running. While most service properties are modifiable; some are read-only. Typically, service properties generally persist until the next session. Runtime changes to some modifiable properties take effect dynamically, while changes to others do not take effect until the service is restarted. By way of example, for a COM-based implementation of the present invention as depicted in the class diagram of <figref idref="f0002">Figure 2</figref>, service properties can be read using the IMCService.GetProperties method and modified using the IMCService.SetProperties method. Preferably, service properties implemented according to the present invention take effect dynamically without requiring a service restart. These methods, for example, accept and return XML strings representing collections of service properties. In this embodiment, XML provides a means of agent application programming, utilizing COM automation, without binary stream parsing or proprietary encoding at the client level. Instead, an easily modifiable, maintainable, and easily debugged transmission medium is provided, allowing for specification of a subset or group of network properties or statistics to retrieve with a given XML document, providing batched statistical transmissions, conserving network bandwidth and compensating for the increased size of XML documents compared to binary streams.

0061XML service statistics obtained according to the present invention may be described generally as read-only snapshots of dynamically changing data. They will typically be available only when the corresponding service is running. Statistics can be read, in the embodiment depicted in <figref idref="f0002">Figure 2</figref>, using the IMCService.GetStatistics or equivalent method.

0062In a preferred embodiment of the present invention when implemented utilizing COM components, all Management Component classes support standard COM error handling by implementing the COM interface ISupportErrorInfo. If alternative encapsulated reusable interface modules are used, preferably existing error handling aspects of these interfaces will be utilized as well. In the COM case, this allows Visual Basic client programmers to utilize the standard VB error handling mechanisms such as the Err object in client applications that call the Management Components. The Management Component interfaces may generate both standard Microsoft-defined HRESULT codes and application-defined HRESULT codes. Application-defined HRESULT codes all have the facility bits set to FACILITY_ITF to indicate that these HRESULTs have meanings specific to these interfaces.

0063In a preferred embodiment of the subject invention, the Management Component interfaces may be configured to return standardized runtime error codes. For example, in an embodiment of the subject invention adapted for administration of a Windows NT server or network, the Management Component interfaces may preferably return any of the standard Microsoft-defined HRESULT codes, e.g., E_NOTIMPL; E_POINTER; DISP_E_EXCEPTION, or other standard HRESULT runtime error codes.

0064It is preferable that in implementing the present invention particularly in a Microsoft environment, application-defined HRESULT codes have corresponding message text stored in a message table resource, such as that found in the file esmcres.dll. In order to support localized remote clients, the server-side Management Components will preferably not write error message text to the Description property of the COM error objects returned to clients. Instead, clients may retrieve error descriptions for Management Components-defined error codes from a local copy of esmcres.dll via the Win32 API function FormatMessage. It is typically preferred that in implementing the Management Component interfaces, support for localizable clients will be implemented without requiring translation of the Management Components themselves, through the XML facility afforded by the present invention.

0065In implementing the present invention in a COM embodiment, and according to the class diagram of <figref idref="f0002">Figure 2</figref>, it will generally be preferred that the certain strings are localizable in the Management Components resource DLL (e.g., esmcres.dll), such as values for all <displayName> elements returned in XML streams from the IMCService.GetProperties and IMCService.GetStatistics methods; values for the certain XML elements returned via the IMCDomain.MCVersionXML, IMCServer.MCVersionXML, and IMCService.MCVersionXML properties, including \\versionInfo\vendor, \\versionInfo\product, \\versionInfo\component, and \\versionInfo\copyright; and the names of the predefined Management Components MTS roles: Administrator and Viewer.

0066Further considering a COM-based embodiment of the present invention, as depicted in <figref idref="f0002">Figure 2</figref>, the Management Components preferably exploit MTS package security. For example, it is possible for the Management Components to predefine multiple MTS roles, e.g., Administrator and Viewer. The Administrator role implicitly includes Viewer permissions. The Management Components will preferably programmatically implement method-level security based on these predefined MTS roles.

0067The present invention preferably provides for XML service statistics to be provided to a network administrator remotely. XML service statistics are preferably implemented as read-only snapshots of dynamically changing data regarding network performance and status. In the COM-based implementation depicted in the class diagram of <figref idref="f0002">Figure 2</figref>, statistics can be read using the IMCService.GetStatistics method or an equivalent.

0068In an embodiment of the present invention, a design decision which must typically be made is the access privileges to be granted to method-level processes implementing the Management Components agents. In the embodiment of the present invention depicted in the class diagram of <figref idref="f0002">Figure 2</figref>, for example, it is preferable that the following Management Component properties and methods allow access by both the Viewer and Administrator roles, in addition to all IMCDomain properties: IMCServer.ServerName, IMCServer.ComputerName, IMCServer.DomainName, IMCServer.IsDomainController, IMCServer.Services, IMCServer.CommonFilePath (read only), IMCServer.CurrentTime, IMCServer.TimeZone, IMCServer.MCVersionXML, IMCService.ServiceName, IMCService.DisplayName, IMCService.Status, IMCService.AcceptPause, IMCService.Server, IMCService.ExeFile, IMCService.StartMode (read only), IMCService.AccountName, IMCService.LastStartTime, IMCService.InstallDate, IMCService.ServiceVersionXML, IMCService.MCVersionXML, IMCService.GetProperties, IMCService.GetStatistics, and IMCService.FlushLog. In contrast, in a COM-based implementation of the present invention, the following Management Component properties and methods preferably allow access by the Administrator role only:, IMCServer.CommonFilePath (write), IMCService.StartMode (write), IMCService.Start, IMCService.Stop, IMCService.Pause, IMCService.Continue, IMCService.SetAccount, IMCService.SetProperties, IMCService.ResetStatistics, IMCRendezvousMgr.RendezvousNow, and all IMCObjectMgr methods.

0069In a preferred embodiment, upon implementation of a COM-based implementation of the present invention as depicted in the class diagram of <figref idref="f0002">Figure 2</figref>, the Management Components allow multiple clients to concurrently utilize instances of an MC class on a server by implementing a caching model for service properties based on optimistic concurrency. This prevents race conditions and access violations of a single MC class by multiple clients. According to this embodiment, service properties may be cached separately for each MTS activity id. (Note that a new activity id will typically be generated each time a client directly creates a Management Components object. All cached properties will preferably persist until the MTS package is deactivated. Therefore, frequent creation of new MC objects by a client may result in excessive memory consumption. This will preferably be avoided by reusing existing MC object references as is provided in a preferred embodiment. The details on MTS activity ids may be reviewed in documentation available from Microsoft Corporation of Redmond, Washington. Accordingly, it will typically be preferred in implementing the present invention that, for example in the implementation depicted in <figref idref="f0002">Figure 2</figref>, calls to IMCService.SetProperties or the equivalent on any of the MC service classes will preferably block other concurrent IMCService.SetProperties calls (but not IMCService.GetProperties calls) across all instances of the same MC class on the same server. Calls to IMCService.GetProperties or its equivalent are preferably nonblocking.

0070For each indicated property, IMCService.GetProperties or the equivalent preferably checks the timestamp of the corresponding cached value in the cache associated with the current activity ID. In one embodiment of the present invention, cached values less than 5 seconds old are returned to the caller without being refreshed. Cached values 5 seconds old or older are refreshed before being returned to the caller.

0071To avoid scenarios in which a user might make modifications based on obsolete information, it is preferred that an interface methods such as IMCService.SetProperties, of interface 132 of class diagram 130, crosschecks the cached value for each indicated property in the cache associated with the current activity ID against the underlying registry value on the server. If one or more cached properties are determined in this way to be obsolete at any point during the SetProperties operation, those properties are preferably not modified and the method returns error 0xC0042000 (one or more properties could not be set). In this event, the associated XML error may list indicates error 0xC0042009 for those properties with obsolete cached values. For example, IMCService.SetProperties or equivalent may be configured in one embodiment to attempt to set all indicated properties even if one or more fail. IMCService.SetProperties or equivalent always refreshes the cache associated with the current activity ID for all indicated properties.

0072In a preferred embodiment of the subject invention, the management components implemented in the present invention provide the information, in the form of XML strings, about the network being monitored and about background processes available on the server being monitored. For example, the Management Components of the subject invention preferably provide XML strings that provide information about, for example, the network server service version, the Management Component version, service-specific properties, and service-specific statistics

0073Any standard XML parser such as Microsoft's (msxml.dll) is thought to be suitable for use to implement the XML aspect if selected of the present invention; and thus to be used to process the XML consumed and emitted by the Management Components. Specifically, XML data types described in this section such as int, boolean, string, and dateTime are consistent with the data types supported by the Microsoft XML parser.

0074In an embodiment of the present invention utilizing COM components in a Windows operating system environment, preferably the IMCDomain.Servers property returns a collection of strings (server names) rather than a collection of COM interface pointers to instantiated MCServer objects. (This stands in contrast to the IMCServer.Services method which returns a collection of interface pointers to objects instantiated on the same machine as the MCServer object) Although this approach typically requires the client programmer to then explicitly create MCServer objects remotely on the named servers, it may be preferable in order to support the scenario in which one or more servers in the domain are down. Objects cannot be instantiated on inactive servers, but inactive server names do appear in the returned collection, enabling the client programmer to detect this situation and present the information accordingly to the user if desired.

0075In a preferred embodiment, XML service properties can generally be read regardless of whether the corresponding service is running. Most service properties are modifiable; some are read-only. Service properties generally persist until the next session. Runtime changes to some modifiable properties take effect dynamically, while changes to others do not take effect until the service is restarted.