Data processing: database and file management or data structures – Database design – Data structure types
Reexamination Certificate
1997-05-02
2003-11-11
Amsbury, Wayne (Department: 2171)
Data processing: database and file management or data structures
Database design
Data structure types
C707S793000
Reexamination Certificate
active
06647393
ABSTRACT:
TECHNICAL FIELD
The present invention relates in general to directory services and, more specifically, to a dynamic directory service that maintains a directory in which is stored both (1) directory information and (2) information identifying the physical layout or structure of the directory.
BACKGROUND INFORMATION
Computer-based structured storage systems, such as computer file systems and database systems, have been remarkably successful at providing users with quick and facile access to enormous amounts of data. Structured storage systems have allowed businesses to generate and maintain enormous stores of persistent data that the company can modify and update over the course of years. For many companies, this persistent data is a valuable capital asset that is employed each day to perform the company's core operations. The data can be, for example, computer files (e.g., source code, wordprocessing documents, etc.), database records and information (e.g., information on employees, customers, and/or products), and/or Web pages.
A typical computer based structured storage system includes a central server that provides centralized control over the structured store of data. The structured store of data is the information that is being maintained by the system, such as information in the files and directories of a file system or within the records of a database system. The central server provides system services to a plurality of interconnected network client nodes, and each of the client nodes employs the central server to access and manipulate the structured store of data.
It is common to use the central network server to provide a directory service, i.e., a specialized hierarchical database of network, user, and other computer system configuration information. This information typically includes operating system configuration information, application program configuration information, network configuration information, network-accessible resources, exported devices and services, network printers, and user account records. Network user account records are what allow network-wide, unified “log on,” and they allow sophisticated application programs to obtain broader, coherent name spaces (e.g., electronic mail system application programs). Novell's Directory Server (NDS), available from Novell, Inc. of Provo, Utah, is one example of software that implements a directory service and that runs on a central server to allow maintenance of and access to directory information.
Although central server directory services such as NDS generally work, problems arise from relying on centralized control. For example, the operation of the network is dependent upon the proper functioning of the central server. Any failure of the server to maintain proper operation, such as a power failure, hardware failure, or other such system failure, will disable the entire network and generally prevent users from obtaining access to the network and its resources. Additionally, a flood of client requests (e.g., access of user account records) can overload the central server and slow down or crash the network. Accordingly, reliance on a centralized, server-based directory service can result in slow operation or total network failure during periods of heavy use.
An additional problem with a client-server network system is that it provides a static operating environment that is set for optimal performance at a certain level of network activity. Consequently, the network fails to exploit available resources to improve system performance. In particular, as the system activity rises above or drops below the expected level of network activity, the static operating environment lacks any ability to reconfigure dynamically the allocation of network resources to one providing better performance for the present level of activity.
Technology has been developed to improve the reliability and operation of a centralized server directory service. This technology involves employing a plurality of central servers. Each of the servers provides a directory service. Whenever the directory information changes, all of the redundant servers are updated so that requests can be made to any of the centralized servers without impacting the correctness of the response.
While this statically replicated technology improves upon the single server arrangement, it generally performs poorly or fails as the size of the network increases. As client nodes are added to the network and more directory servers are added to the network to handle the corresponding increased network load, the sustainable update rate of information managed by the servers decreases because the overhead and complexity of propagating updates (i.e., changes to the data stored in and replicated across the directory servers) increases with the increased network size. Thus, known directory services are inherently read-mostly repositories, and that is the way they are designed and used. That is, known directory services are used only for infrequently-updated directory information.
Examples of this centralized, statically replicated, hierarchical directory service technology include Microsoft's Active Directory (NT 5.0), NDS, Banyan's Streetalk, and X.500 directory services. Lightweight Directory Access Protocol (LDAP) is a “common” protocol that can be used to access data from any compatible directory server such as NDS.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a dynamic directory service that is an improvement over centralized, statically replicated, hierarchical database directory services.
It is also an object of the invention to provide a dynamic directory service that maintains a directory in which is stored both (1) directory information and (2) the physical layout of the directory itself. That is, the invention involves the use of a directory having both information about where to find the directory information of interest as well as the actual directory information.
It is a further object of the invention to provide a dynamic directory service that is more reliable and provides improved fault tolerant operation over existing directory services, and that has the ability to replicate and move data dynamically in response to network activity levels and access patterns. This ability optimizes performance and minimizes the time required to provide directory information (e.g., network configuration information, organizational information, user configuration information, and network-accessible resources such as exported devices and services, network printers, and user account records) to requesting network nodes.
It is yet another object of the invention to provide a dynamic directory service that provides distributed control over a structured store of directory information and that allows that information to be changed and/or updated with higher frequency than generally possible with existing directory services without adversely effecting network performance or network node access times.
It is still another object of the invention to provide a dynamic directory service that maintains and allows access to frequently-changing, as well as infrequently-changed, directory information.
The directory service of the invention maintains both the physical location information and the directory information itself in the same data structure. That data structure is distributed around the network, and all of the directory information is homeless (except, usually, a root record). The distributed directory service of the invention allows network nodes to locate copies of records to which the nodes want access. A globally unique identifier (GUID) is associated with each record as a unique index key that can be used to identify the record on the network. It contains no location information, and a given record can be physically located anywhere on the network. Each of the records also can migrate from physical location (node) to physical location (node) around the network. The invention provides automatic migration and/or replication of directory i
Abraham William
Carter John B.
Davis Scott H.
Dietterich Daniel J.
Frank Steven J.
Amsbury Wayne
Mangosoft Corporation
Proskauer Rose LLP
LandOfFree
Dynamic directory service does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dynamic directory service, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamic directory service will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3184716