We have already introduced the four Performance Monitor views. In this section we discuss the details of each view and what each brings to the party. First we will explore the views as we observe current activity in real time. Then we'll note how things change when the same views are applied to an existing log file.
The four views operate independently and concurrently, but you can only look at one at a time. They each fetch data independently from the target computers, so looking at a counter in all four views is four times the overhead of looking at the same counter in just one view. Luckily, this overhead is designed to be small, so concurrent use of views is not a problem. Although this may seem like a design flaw, in practice the views typically are looking at different computers or counter instances so the practical savings of combining data retrieval are not typically impressive.
To switch between the different views, choose the view you want from the View menu.
We discuss two other features of Performance Monitor in depth at the close of this chapter, but we introduce them here briefly. These are the Settings Files and the Export command, both of which are in the File menu.
When you use Performance Monitor, you choose which counters to look at. You also make decisions about the features of the display, the frequency of counter updates, even the position of Performance Monitor on your screen. All the attributes of your measurements can be saved in settings files and opened later for instant use. In fact, whenever you start to make choices in Performance Monitor, it is building up a record of your selections that you can save at any time. You can save the settings file of any particular view, such as a chart, independently of the settings of your other views. You can also save the settings of all your views at once in a special settings file called a workspace. You will find settings files to be an important time saver when using Performance Monitor, and we discuss using them in some detail in "Saving Settings," later in this chapter.
We like to think Performance Monitor will provide an acceptable interface for viewing data most of the time. But every tool has its limitations. We have therefore included the capability for exporting performance data, as either tab- or comma-separated ASCII files. You can then feed these files into spreadsheet or database programs, as well as editors or custom programs you may want to write. Using these other programs, you can decorate, analyze, and present the data in any way you choose. Export capability helped us keep the Performance Monitor interface relatively simple. We'll discuss exporting in more detail in "Exporting Performance Data," later in this chapter.