pGraph Interactive Mode
Performance data is usually collected for a long time period with high sampling time to be able to detect most system events. Administrator must then look at the entire period, compare several statistics (for example CPU, memory and disk I/O), identify which time periods require attention and finally figure out which kind of workload was running.
The pGraph tool is designed to ease this kind of activity enabling the user to visualize data in a graphical format and allowing the selection of the relevant time periods. A Checker method is also available to make the tool search for user defined patterns and present the time periods when the patterns occurred.
The tool is invoked with the following syntax:
java -cp pGraph.jar pGraph.Viewer
In the main Viewer window the user loads data using the File menu. Several options are available:
- Single file
- Directory: MULTIPLE hosts, multiple files
- Directory: SINGLE host, multiple files
The tool is capable of reading either a single data file or all performance data contained in a specified directory. The tool automatically detects the file type and skips unsupported file formats. In the bottom of the window the single file name with its data type or the name of the selected directory is shown.
The Viewer window has two main controls:
- Time selection sliders
- Performance data buttons
All performance graphs provided by the tool are always related to the time period shown in the Viewer window. The sliders and buttons in the time selection area change the time focus and cause all graphs to be regenerated reflecting the selected time frame. All graphs are always related to the same time frame.
When a new set of data is loaded, the tool closes all performance graphs and resets the time frame to contain all data.
The data buttons select which kind of data has to be shown. Each button creates a new window that has its own set of controls to select performance data, change the display time frame and to create a picture of data in PNG format. For details see window components.
