Analyzing RPC Activity
When you run ExPTA, you can select the type of performance symptom that you want to analyze on the page that Figure 2 shows. This option displays automatically at the start of an ExPTA session. The current list of analysis options might change over time as Microsoft updates and enhances the tool. For example, if you're experiencing performance problems on an Exchange server, you can tell ExPTA to analyze the remote procedure call (RPC) activity on your selected server, by selecting the The number of RPC operations per second is higher than expected option.
However, when you select this option, there's a catch. If you want to analyze RPC activity, you must first collect the RPC-tracing information and put it in the event trace log (.etl) files by using the Exchange Server User Monitor (ExMon) tool. (For more information about how to use ExMon, see "Getting Started with ExMon," October 2005, InstantDoc ID 47215.) After you collect the RPC-tracing information, ExPTA can analyze the .etl files and report on the performance of the server under investigation.
As I mentioned earlier, you should install ExPTA on a workstation and not on an Exchange server. However, there is one exception to this rule: If you haven't used ExMon to collect RPC-tracing information before analyzing the RPC activity, you can opt to have ExPTA collect the RPC-tracing information on the Exchange server on which ExPTA is installed. To enable ExPTA to do so, you'll need to check the Collect the Exchange Server User Monitor (ExMon) Trace data for me box on the Analyze User RPC Activity page. ExPTA then collects the RPCtracing information for a period of five minutes, after which it can analyze the data. I suggest you perform this datatracing activity on the Exchange server when you're experiencing performance problems.
Usually, you'd examine the RPCtracing information only if you were trying to pinpoint the source of a known performance issue. However, if you believe your Exchange server is busier than typical, it's worthwhile to run the RPC checks. In some cases, even when the target server has a low overall connected-user load, the load might generate heavy RPC communications and specific users could experience impaired performance. If ExPTA detects an unusually high workload (e.g., increasing response times for users, excessive I/O response times) from Outlook users or from other Messaging API (MAPI)-based applications, ExPTA will isolate the cause of the problem. More generally, you might use the RPC-tracing feature of ExPTA to analyze your Exchange server's configuration and performance counters to proactively manage performance issues.
Analyzing Server-Performance Bottlenecks
The other performance symptom you can choose to have ExPTA analyze is the Multiple users are complaining... option that Figure 2 shows. When you select this option, ExPTA will identify problems on the Exchange server by performing a series of checks, including connectivity tests, performance counter tests to pinpoint high latencies, configuration tests on disks and file locations, disk-health tests, and miscellaneous tests on general performance, memory, and processor counter checks. Figure 3 and Figure 4 show sample results from the Disk Drive and Exchange Data File and Disk Drive Performance Counter tests. These checks are useful when you're trying to troubleshoot problems reported by multiple users who have experienced delays when switching from one folder to another, or when those annoying Outlook pop-up messages (familiar to Outlook 2002 and earlier users) appear stating that Outlook is waiting for an operation to finish. When you're trying to trace problems associated with a particular mail application, you'll find that problems related to Outlook users will manifest as excessive RPC latency, whereas problems with other clients, such as Outlook Web Access (OWA), will show up as server-related performance bottlenecks.
As Figure 5 shows, after ExPTA completes all its checks, it summarizes and documents the results. Just as you can in ExBPA, you can click each highlighted area for more information and links to Microsoft articles for further explanation and clarification.
ExPTA stores its analysis data in XML format in the data-directory location you specified during installation. At any time, you can view previous reports by choosing the Select a Result File to View menu option at the left side of the ExPTA window. You can import a result file into ExPTA directly if you know its name and location. Result files have the naming structure ExPTA.ID>.data.xml, where ID> is derived from a combination of the file's date-and timestamps and other items.
Moving On
ExPTA certainly isn't the Holy Grail of performance-analysis tools. But it's a first step toward simplifying complex and confusing Exchange performance tuning and troubleshooting. Today's ExPTA tool is limited in its capabilities, and it analyzes only fundamental performance characteristics. But its limited scope shouldn't diminish its worth. The tool is best suited for small-to-midsized Exchange installations ( perhaps where it will be most warmly received), but its fundamental concepts are equally applicable to large installations. If you do run it on your large, well-tuned Exchange server with oodles of high-performance SAN-based storage, there's always the possibility that it might uncover something that you've missed.
Using the development of its big brother ExBPA as a guide, over the coming 12 to 18 months we can expect ExPTA to evolve into a more useful analysis tool that identifies, examines, and highlights all manners of performance issues. ExPTA focuses on performance issues that manifest themselves to users; however, even if your users aren't complaining about poor performance, ExPTA is a useful tool to discover performance problems that are waiting to happen. Maybe someday, in the not-too-distant future, ExPTA will also be able to fix those problems.