The Performance Data Collector (TDC) for OpenVMS provides a C and C++ API for managing collection and processing of performance-related metrics. It supports both file-oriented and live processing of collected data.

The Performance Data Collector (TDC) for OpenVMS provides a C and C++ API for collecting and processing approximately 1,000 performance-related metrics which include storage utilization and I/O; cluster communications; network performance; lock manager performance; process metrics; memory, CPU, server, file system, and cache utilization and performance; paging performance; and SYSGEN parameters. The data is collected in snapshots taken at regular intervals and written into a file; both file-orienced and live processing of the data is supported. The data may be based on information collected from system services, other applications, or derived from data records provided during the current operation by other TDC modules. The data records are then read from a file, and a snapshort structure is populated with them. The API supports two standard operations: data collections, in which data is collected for processing, and data-extractions, in which data in a file is extracted and processed.

You can develop new software that uses TDC, or integrate TDC into an existing application by writing a client application to drive the TDC modules to collect and manipulate data, or by developing new TDC processor modules. The TDC API has been developed for use by “C” (and “C++”) code; the API can be accessed by code written in other languages by developing C wrappers for the API function calls. Multiple instances of the TDC software can safely run concurrently within a single OpenVMS system; they do not share data. None of the software provided with TDC is multi-threaded, although that need not preclude its use with multi-threaded software. Processor Modules are invoked sequentially at appropriate times, and each usually “has the stage” for the duration of its invocation. Processor Modules can, and several of those shipped with TDC do, perform “background” activities to assist in their operations, perhaps to poll for device status or I/O activity. Those TDC-supplied Processor Modules that do background processing use timer events and AST routines for that purpose.

The Performance Data Collector (TDC) is available on Alpha and Integrity.

Latest Version

Alpha Integrity
2.3-1220 2.3-1220a


Base OS