What are different Performance counters?

Hi friends,

Here again a good question like my last one"From where test data come?"

Now we will discuss on Performance counters.
So, start explaining

"What are different Performance counters are? and how they help us in rating the quality of our product?"

Start now...

The first and foremost question to address when measuring performance of a web application is "What to measure?" This can be answered by following:
[LIST][*]Identifying and recognizing events that already occur naturally within the application. This method places the burden on those setting up measurements to first identify application-specific milestones.[*]Adding instrumentation, by inserting simple monitoring calls like those used by the ARM(Application Response Measurement) standard [ARM1], an existing method for measuring distributed applications. In this approach, developers imbed simple instrumentation calls at logical boundaries in the application’s flow, to enable its subsequent measurement [ARM2]. This frees the measurement tool from the need to know anything about the application, but places the burden on application developers to instrument their code by inserting markers at key points[/LIST]

The following 10 points highlight the purpose of measuring performance of any web application -

[LIST=1][*]Verifying that an application meets its service level objectives[*]Detecting abnormal application behavior (typically, slow response)[*]Identifying bottlenecks in application components[*]Comparing builds, versions, or releases of an application[*]Comparing two applications that perform comparable functions[*]Verifying that a system will be able to handle the projected traffic[*]Determining how many users a server environment can handle[*]Predicting bottleneck components as workload levels grow[*]Comparing builds, versions, or releases of an application[*]Identifying components that fail after extended use[/LIST]

Good dsharma;
Good answer from your side, but friend i am looking for counters like request per second, total number of request per sec, no of page fault, like this.

What so ever you have answered is related to performance but not the performance counter.I hope more from your side.So, please reply , i am waiting for your post.

When it comes to manual testing, we rely on the factors that I have jotted for performance. The counters you are talking about is taken care by Automated Testing using LoadRunner or SilkPerformer, etc. wherein we have to give various conditions to calculate the performace of an application to the last second.

Performance Monitoring is a complex subject and in some ways more of an art than a science. It can be daunting to be confronted with a choice of over a thousand performance counters to choose from. Which ones are important to monitor on a regular basis and which ones can be largely ignored? A lot depends on the role of the system you want to monitor and whether you're talking about capacity planning, ensuring availability, scaling upwards, monitoring for possible problems, or troubleshooting issues that have arisen.

[B]System\System Up Time counter[/B], tells you how many seconds it's been since your server last rebooted.