Troubleshooting a performance problem can be very complicated.  Unfortunately, in many cases you prepare and begin learning about how to fix a performance problem when it is happening or just after a performance problem.  The fact is, you need to monitor your system and gather statistics on what is considered “standard operating performance” before a performance problem occurs.  I mean the simple question is, “how do you know there is a performance problem if you have nothing to compare it against?”

Some good performance counters to begin setting a performance base line are shown in Table 1 and in Figure 1:

Performance Object

Performance Counter

Short Description

ASP.NET

Application Restarts

Number of times the application has been restarted during the web server's lifetime.

ASP.NET

Requests Queued

The number of requests waiting to be processed.

ASP.NET

Worker Process Restarts

Number of times a worker process has restarted on the machine.

ASP.NET Applications

Errors Total

Total number of errors occurred.

ASP.NET Applications

Requests/Sec

The number of requests executed per second.

ASP.NET Applications

Pipeline Instance Count

Number of active pipeline instances.

Processor

% Processor Time

% Processor Time is the percentage of elapsed time that the processor  spends to execute a non-Idle thread

.NET CLR Exceptions

# of Exceptions Thrown

Displays the total number of exceptions thrown since the start of the application.

System

Context Switches/sec

Context Switches/sec is the combined rate at which all processors on the computer are switched from one thread to another.

Table 1, sample performance monitor counters

 

Figure 1, a possible performance counter setup for tracking performance

Significant capabilities can be found in the Performance Monitor tool.  This following instructions represent a manual implementation which may or may not fit into your requirements.  For detailed information about Data Collectors, System Diagnostics, System Performance and Reporting, please review the Technet document found here.

Setting up a manual performance monitor

To set this up click on Start -> Run -> “Perfmon”, this will open the Performance Monitor tool as shown in Figure 2.

Figure 2, Performance Monitor version 6.1.7601

Click on the Green + (plus icon) and you are presented with a modal window which enables you to add Performance Counters as shown in Figure 3.  Refer to Table 1 for some recommended performance monitor counters, their descriptions and associated objects.

Figure 3, adding counters to the Performance Monitor

You can save the Performance Monitor by right-clicking the performance monitor graph -> Save Settings As…, as shown in Figure 4.  This will let you save the performance log as an HTML file.  When you open the file it lets you scroll through counters to view the Last, Average, Minimum, Maximum and Duration for each counter.  As well, you can click on different points of the graph to see what the values were at any given point.

Figure 4, save the performance counters to an HTML file

Conslusion

System performance monitoring is a very important aspect, not only in regards to past and present performance metrics.  It is also possible to use the performance logs such as Requests/Sec or Sessions Total to show a possible increase in the usage of the system.  This graph could then be used for planning future growth of a system which may result in hardware upgrades or system optimization programs.  

Within large scale systems where the complexity exceeds the capacity of a single mind, metrics are a very powerful tool which can bridge that gap, I recommend that you create and use them.