Abstract: Methods and apparatus for implementing a persistent storage interface that may be used to store entries into a variety of different storage subsystems are disclosed. According to one aspect of the present invention, an object-based system which is arranged to store and to retrieve configuration information includes a server and a client that is in communication with the server. The client communicates with the server using a client/server protocol. The system also includes at least one persistent agent that is arranged to store persistent entries, as well as a persistent storage application programming interface that allows the server to communicate with the at least one persistent agent. The persistent storage application programming interface is arranged to support multiple persistent agents such that different persistent agents may be used with respect to the system. In one embodiment, the object-based system is a Java System Database.

Abstract: A computer-implemented method for allocating memory resources to a device driver is described. In one embodiment, a device driver generates a request for memory allocation in terms of an abstract memory address space. This abstract memory address space is also used by a bus manager to manage the allocation of memory. The driver forwards the request to the bus manager which can then allocate memory or translate the request to a second abstract memory address space used by a second bus manager. When the request is passed to a platform manager, real memory is allocated and the requested memory is passed back to the driver. Thus, by making a memory request in terms of a bus manager's abstract memory address space, the necessity of coding the driver to request real addresses (a platform-specific operation) is avoided.

Abstract: Methods, apparatus, and software for endianness checking for platform-independent device drivers is described. According to one embodiment, the method of the invention includes generating a memory allocation request from a platform-independent device driver. The driver instantiates a memory constraints object that is configured to report the endianness of the driver. The request is received by a bus manger that is configured to process memory allocation requests from the device driver and has an endianness independent of the device driver. If the endianness of the bus manager and device driver is inconsistent, then the memory constraints object is transformed to be consistent with the bus manager's endianness.

Abstract: A cluster implements a virtual disk system that provides each node of the cluster access to each storage device of the cluster. The virtual disk system provides high availability such that a storage device may be accessed and data access requests are reliably completed even in the presence of a failure. To ensure consistent mapping and file permission data among the nodes, data are stored in a highly available cluster database. Because the cluster database provides consistent data to the nodes even in the presence of a failure, each node will have consistent mapping and file permission data. A cluster transport interface is provided that establishes links between the nodes and manages the links. Messages received by the cluster transports interface are conveyed to the destination node via one or more links. The configuration of a cluster may be modified during operation.

Abstract: Methods and apparatus are disclosed for providing a data framework and associated client/server protocol for storing and exchanging data among computers in a network. A data schema having an n-way tree-type structure with a root node layer, intermediate node layers, and a data layer for storing configuration data is described. The intermediate node layers contain a multitude of nodes containing categorical information relating to components and various aspects of the computer network. Following a tree structure, each intermediate node and root node has branches emanating to nodes below it. These subordinate nodes are referred to as children nodes. The data node layer is at the bottom of the tree and contains actual specific configuration data relating to components and other aspects of the computer network, such as information regarding users registered to use the network.

Abstract: Methods and apparatus are disclosed for providing a data framework and associated client/server protocol for storing and exchanging data among computers in a network. A data schema having an n-way tree-type structure with a root node layer, intermediate node layers, and a data layer for storing configuration data is described. The intermediate node layers contain a multitude of nodes containing categorical information relating to components and various aspects of the computer network. Following a tree structure, each intermediate node and root node has branches emanating to nodes below it. These subordinate nodes are referred to as children nodes. The data node layer is at the bottom of the tree and contains actual specific configuration data relating to components and other aspects of the computer network, such as information regarding users registered to use the network.

Abstract: A method and system for creating and maintaining a journal of transactions directed to a configuration database is disclosed. A multi-threaded journaling method logs transactions in a configuration database by first receiving a database transaction, the transaction being either a single modification, e.g. insertion, deletion, update, or a series of modifications directed to the configuration database. An initial entry is inserted into a journal file where the initial entry includes a transaction identifier or handle that corresponds to the database transaction. Subsequent entries are inserted into the journal file corresponding to the specific updates of the transaction, the subsequent entry containing the transaction identifier and actual transaction data relating to the specific update. The journaling mechanism then determines whether each of the specific updates to the configuration database has been successfully completed.

Abstract: A method and system are disclosed for updating and managing a configuration database used to store configuration and user data in a computer network having multiple clients, such as network computers. The transaction management mechanisms described determine whether new data, such as a new user or specific property, is being added to the configuration database or whether an existing node in the database is being modified by a transaction. A locking mechanism obtains a lock on a node according to whether a new node is being added to the configuration database or an existing node is being modified. During this process, an identifier is assigned to the transaction that caused the lock that acts as a transaction handle. The transaction then proceeds to modify the configuration database by either adding new data or modifying existing data.

Abstract: Methods and apparatus are disclosed for providing a data framework and associated client/server protocol for storing and exchanging data among computers in a network. A data schema having an n-way tree-type structure with a root node layer, intermediate node layers, and a data layer for storing configuration data is described. The intermediate node layers contain a multitude of nodes containing categorical information relating to components and various aspects of the computer network. Following a tree structure, each intermediate node and root node has branches emanating to nodes below it. These subordinate nodes are referred to as children nodes. The data node layer is at the bottom of the tree and contains actual specific configuration data relating to components and other aspects of the computer network, such as information regarding users registered to use the network.

Abstract: The cluster configuration database is a distributed configuration database wherein a consistent copy of the configuration database is maintained on each active node of the cluster. Each node in the cluster maintains its own copy of the configuration database and configuration database operations can be performed from any node. Configuration database updates are automatically propagated to each node in a lock-step manner. If any node experiences a failure, the configuration database uses a reconfiguration protocol to insure consistent data in each node of the cluster. The cluster configuration database uses a two-level consistency update framework to insure consistent data among the nodes. Each local configuration database uses a self-contained consistency record to uniquely identify and stamp each copy of the configuration database. The consistency of each individual copy of the configuration database can be verified from the consistency record.

Abstract: A cluster implements a virtual disk system that provides each node of the cluster access to each storage device of the cluster. The virtual disk system provides high availability such that a storage device may be accessed and data access requests are reliably completed even in the presence of a failure. To ensure consistent mapping and file permission data among the nodes, data are stored in a highly available cluster database. Because the cluster database provides consistent data to the nodes even in the presence of a failure, each node will have consistent mapping and file permission data. A cluster transport interface is provided that establishes links between the nodes and manages the links. Messages received by the cluster transports interface are conveyed to the destination node via one or more links. The configuration of a cluster may be modified during operation.