Abstract: The invention is directed to techniques for managing access to data available from a data access device using a network switching protocol to manage content requests from clients. A data communications device receives a request for content from a client. The data communications device, such as a network switch, exchanges signals using the network switching protocol with one or more data access devices, such as a web cache. The data communications device can then select one data access device to provide the requested content to the client based, for example, on load balancing considerations. The data communications device sends a data transfer approval signal to the selected data access device. The selected data access device establishes a connection with the client using information, such as the client's network address, provided by the signals. The selected data access device then bypasses the data communications device and sends the requested content to the client.

Abstract: A hierarchical registration architecture manages and organizes the collection of performance information, such as statistics and tracing, for an extensible operating system of a computer. The registration architecture, or registry, comprises a multi-linked tree data structure within a main memory for accessing the performance information. Writer entities register their intent to collect and store performance information in the registry by creating objects, via novel API calls, as nodes organized within the tree structure. Each object node of the registry is named according to a convention that identifies the type of performance data collected by that node. Each object node further represents a single data item having a single data type for collecting the performance and a reference to the actual storage location of its collected performance information. Information storage preferably occurs in globally-shared memory so that any software entity can access the information.

Abstract: A computer system handling multiple applications wherein groups of I/O services are accessible through separate application programming interfaces. Each application has multiple application programming interfaces by which to access different families of I/O services, such as I/O devices.

Abstract: A synchronization arrangement provides writer and reader entities access to an information resource, such as a trace buffer, located in a registry of a computer. The arrangement comprises a counter upon which atomic increments are performed to allocate entries of the trace buffer for temporarily storing trace message fragments provided by the writer entities. The arrangement also comprises reassembly queues for temporarily storing the message fragments sequentially retrieved from the trace buffer by the reader entities.

Abstract: A run-time data type extension mechanism describes the kinds of performance information collected within a registry located in a main memory of a computer. The data type extension mechanism comprises a base node of a multi-linked tree data structure having associated therewith a buffer portion for storing the collected performance information and a description portion for describing that information. Writer entities specify the contents of these latter portions, i.e., the collected information and its description, at run time to provide an arrangement for dynamically extending the kinds of information collected at the registry.