When you think about performance management in a Windows environment, the first thing that comes to mind might be the ubiquitous Performance Monitor tool. Performance Monitor has been the go-to tool for performance information since Windows NT's early days. Alternatively, you might choose Task Manager or Windows Management Instrumentation (WMI), which exposes Performance Monitor data and provides a model for exposing other types of management information related to performance. Here I provide tips about how you can get the most from some old but updated friends—such as Performance Monitor and WMI—and I highlight some new Windows XP tools and explain how you can use them to determine how your systems are performing.
What Is Performance Management?
For many administrators, performance management in Windows means running Performance Monitor and checking CPU utilization, disk busy time, or memory pressures on your servers. Usually a performance problem triggers you to use Performance Monitor—maybe the server is responding slowly or users are unable to access the server. This approach, which I call "performance firefighting," isn't ideal. For effective performance management, you need to track your servers' performance before something goes wrong. Taking a proactive approach to performance management lets you determine what is typical. Armed with this data, you can then determine when things aren't running smoothly and what the cause might be. You can also use proactive performance data to plan for future capacity needs. For example, if you know that your Microsoft IIS-based Web server runs at 60 percent CPU utilization with 200 simultaneous visitors to your site, you can estimate when the server will max out and how many users you can handle when it does. Based on your site's growth rate, you can also determine when you'll need to buy new hardware.
A system's performance depends on several factors, such as CPU utilization, CPU queue length (i.e., how many tasks are waiting for the CPU to service them), disk busy time (i.e., how much of a disk drive's time is spent satisfying requests), disk queue length (i.e., how many requests are waiting for the disk to service them), available physical memory, and network interface utilization. Table 1 outlines the most important Performance Monitor counters to watch in each of these areas. Unfortunately, few counters have a magic limit beyond which you need to be concerned. Memory pressures that result in a low Available Bytes metric can be the result of a poorly written application that leaks memory or a system that's under-equipped for its workload. You need to continually monitor the most important metrics to determine what is typical for the workload on your systems. You should be able to easily spot changes and quickly remedy your performance problems. You also need to watch for trends as your server workloads change. For example, if you're adding new users to a Web server every week, you'll probably notice increases in the counters during heavy use periods. Bottlenecks in system capacity often begin in one area (e.g., memory) and cascade across other system areas, such as CPU and I/O capacity.
Performance Monitor Revisited
Performance Monitor is still your best friend in XP and Windows 2000. The tool has had some improvements since NT 4.0 that provide additional capabilities. In Win2K, a Microsoft Management Console (MMC) snap-in implements Performance Monitor's capabilities. If you start Performance Monitor in XP or Win2K, you get the MMC window that Figure 1 shows.
When you start Performance Monitor in XP, the tool has three preloaded counters: Pages/sec, Avg. Disk Queue Length, and % Processor Time. If you want to start Performance Monitor without any counters, you need to remove the read-only file attribute on the perfmon.msc file in the \%systemroot%\system32 directory. Go to a command prompt and enter
attrib r "perfmon.msc"
Start Performance Monitor, then highlight each counter and click the black X at the top of the System Monitor chart to delete the three counters. Select File, Save to save the changes to the console. To reflag the file as read-only, go to a command prompt and enter
attrib +r "perfmon.msc"
System Monitor
In NT 4.0, Performance Monitor contains a realtime chart, as well as logging and alerting features. XP and Win2K's Performance Monitor separates these functions. In XP and Win2K, the realtime chart is called System Monitor. Below System Monitor, you'll see the Performance Logs and Alerts tool. You can think of the System Monitor control as strictly a performance dataviewing tool. You can view realtime information, but you can't save the data. Click the plus symbol at the top of the System Monitor chart to add performance counters. System Monitor's Performance Logs and Alerts tool collects historical performance data that you can view. To create an MMC tool that includes just the System Monitor tool, open a blank MMC window and select File, Add/Remove snap-in. Select Add, then select ActiveX Control from the list of available snap-ins. Select System Monitor Control from the list of controls.
Previous
Register
