Guy’s Best Practice & Litmus Tests Ezine #16 – Performance Monitoring
Litmus Test – Attitudes to Learning
Professionals Say – Learning is for life
Amateurs Say – You will never get me back in that classroom.
This week’s theme is learning a new skill. My best work is often setting people on the road to learning a new program or executable. What I find is that once people get to a certain stage, then they can learn the rest of the program for themselves. Assuming that you have little or no knowledge of Performance Monitor, this week’s challenge is to begin a new adventure with Perfmon.
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Calculating IP Address ranges is a black art, which many network managers solve by creating custom Excel spreadsheets. IPAT cracks this problem of allocating IP addresses in networks in two ways:
For Mr Organized there is a nifty subnet calculator, you enter the network address and the subnet mask, then IPAT works out the usable addresses and their ranges.
For Mr Lazy IPAT discovers and then displays the IP addresses of existing computers. Download the Free IP Address Tracker
Contents for ezine #16
Why learn performance monitor? The classic reason is so that you can identify bottlenecks on your network. Trust me, every network has a bottleneck, moreover once you find it, there is always another bottleneck. The benefit is, that as you find and remove these bottlenecks, so your network runs faster. Other good reason for using performance monitor is that it pushes you to learn more about the underlying processes. For instance, if you monitor memory, performance monitor prompts you to discover more about available bytes, paging and working sets.
If you are migrating to a bigger and better system, then performance monitor will aid capacity planning. You can play ‘What if’ games. If your server is running at 60% with 2000 users, how many users can we add before it reaches 75% which is the maximum load to place on the server? Answer = 500 more.
Even when you are expert at Perfmon, always start with the big 4 counters, Memory, Processor, Disk and Network. One reason is that you must identify the bottleneck source not the symptoms. For example, a memory problem can masquerade as a disk problem. If you monitor only disk counters, then you may deduce that a queue of 10, and disk usage of 99% means you have a disk problem. Wrong. If you also measured memory, you may find that its shortage of memory that is causing excessive paging hence the disk activity.
Back to getting started. I presume you are running Windows 2000 or XP. To launch Performance Monitor go to: Start, Run Perfmon (type); or Start, Programs, Administrative Tools, Performance. Assuming Performance Monitor (Perfmon) is running, click on the + (top menu) and then select Add and Close. You have just added the default counter, Processor, % Process time. What should happen is that a trace like a heart beat goes across the screen. If you execute a program, such as Word, then the trace should show a corresponding spike.
How do you use this to check for bottlenecks? The answer is experience. However, I will help you with some quick figures, if the trace is continuously above 75% then you have a processor bottleneck. Spikes are o.k. provided they drop below 75% once the program launches.
Let us try another counter, this time Memory, Available Bytes. Once more click on the +, but this time, tickle the Performance Object box, and select Memory, now scroll up and select Available Bytes. If you could also add pages /sec.
When looking for bottlenecks, memory is the most productive place to start. Memory is the most likely bottleneck, and it is relatively easy to fix with another stick of RAM. How would you identify a memory bottleneck? If the Available Memory is less than 10,000 (careful counting the zeros) and paging is greater than 50 pages a second.