Windows XP Professional provides two tools for monitoring resource usage: the System Monitor snap-in and the Performance Logs and Alerts snap-in. Both of these snap-ins are contained in the Performance console. You use the System Monitor snap-in to track resource use and network throughput. You use the Performance Logs and Alerts snap-in to collect performance data from the local or a remote computer.
To access the Performance console click Start, click Control Panel, click Performance And Maintenance, click Administrative Tools, and then double-click the Performance shortcut. The Performance console contains the System Monitor snap-in and the Performance Logs and Alerts snap-in (see Figure 15.11).
You use System Monitor to collect and view real-time data about memory, disk, processor, network, and other activity on your computer or on remote computers. You can view this data in a graph, a histogram, or a report. To change the display you can click the appropriate icon, as shown in Figure 15.11, or use the following key combinations: Ctrl+G for the graph, Ctrl+B for the histogram, and Ctrl+R for the report.
Monitoring resources on your computer and overall system performance can help you to do the following:
System Monitor helps you gauge a computer's efficiency and locate and resolve current or potential problems. You monitor resources on your computer by selecting objects in System Monitor. A set of counters exists for each object; Table 15.10 describes some of the available objects.
Table 15.10??Partial List of Available Objects in System Monitor
Adding counters, such as those described in Table 15.10, to an object allows you to track certain aspects of the object. The following steps allow you to add counters to an object in System Monitor:
The Add Counters dialog box appears.
You can add all counters, but that usually provides more information than you need or can interpret.
For an explanation of a counter, select it and then click Explain.
Table 15.11 explains a few of the counters you might find useful in evaluating your system's performance.
Table 15.11??Partial List of Counters Available in System Monitor
Under Processor, choose % Processor Time
Indicates the percentage of time that the processor spends executing a nonidle thread, which is the percentage of time that the processor is active. During some operations this might reach 100%. Periods of 100% activity should only occur occasionally.
Under Processor, choose Interrupts/Sec
Indicates the average number of hardware interrupts the processor is receiving and servicing in each second. It does not include deferred procedure calls (DPCs). This counter value is an indicatorof the activity of devices that generate interrupts, such as the system clock, mouse, network adapter cards, and other peripheral devices. If the Processor Time value is more than 90 percent and the Interrupts/Sec value is greater than 15 percent, this processor is probably in need of assistance to handle the interrupt load.
Under Processor, choose % DPC Time
Indicates how much time the processor is spending processing DPCs. DPCs are software interrupts or tasks that require immediate processing, causing other tasks to be handled at a lower priority. DPCs represent further processing of client requests.
Under System, choose Processor Queue Length
Indicates the number of threads in the processor queue. There is asingle queue for processor time, even on computers with multiple processors. A sustained processor queue of greater than two threads usually indicates that the processor is slowing down the overall system performance.
You use Performance Logs and Alerts to record performance data and system alerts. You can automatically collect performance data from the local computer or from remote computers. You can view the logged data from System Monitor or you can export it to a spreadsheet program or a database, such as structured query language (SQL). The details pane of the console window shows logs and alerts that you have created (see Figure 15.12).
Table 15.12 explains the information provided by the columns in the details pane.
Table 15.12??Performance Logs and Alerts Columns
When you are ready to begin monitoring the resources on your system, the first thing you need to do is establish a baseline. A baseline is a measurement derived from collecting data over an extended period of time. The data should reflect typical types of workloads and user connections, but should also include any unusual activity that might occur. The baseline represents resource usage under normal conditions.
Once you have collected data on performance over an extended period of time, with data reflecting periods of low, average, and high usage, you can determine what is acceptable performance for your system, and that determination becomes your baseline. You use the baseline to determine when bottlenecks are developing or to watch for changes in usage patterns. Determining bottlenecks will help you in troubleshooting problems that might arise. Watching for changes in usage patterns will help you plan for the future.
Deviations from your baseline are good indicators of performance problems. A bottleneck exists if a particular component's limitation is slowing the entire system performance. Even if one component in your system is heavily used, if the other components or the system as a whole are not slowed down, there is no bottleneck.
If you discover a bottleneck on your system, here are some basic suggestions to help you solve the problem:
In this practice, you use System Monitor to monitor system resources. You add objects and counters to control what is being monitored, and you then view the three views-graph, histogram, and report-for output.
Windows XP Professional starts the Performance console with the System Monitor selected.
What objects and counters are selected by default?
Windows XP Professional displays the Add Counters dialog box.
What performance object is selected by default?
Windows XP Professional displays an Explain Text dialog box indicating that Interrupts/Sec is the average number of hardware interrupts the processor receives and services each second.
The following questions will help you determine whether you have learned enough to move on to the next lesson. If you have difficulty answering these questions, review the material in this lesson before beginning the next lesson. The answers are in Appendix A, "Questions and Answers."