APM Application Performance Tools are crucial in monitoring the performance of applications.

They give a better insight into the behaviour of your applications and are worth it.

New Relic is the most well known one but there are others in the market as well.


This the top 5 memory consumers of w3p processes in an IIS web server.

New Relic has a few criteria for mesuring app performance

  1. Apdex

  2. Response Time

  3. Throughput

  4. Errors

The Apdex score is a ratio value of the number of satisfied and tolerating requests to the total requests made.

An Apdex score varies from 0 to 1, with 0 as the worst possible score and 1 as the best possible score.

This helps in determining the user experience of your web app.

Apdex = Satisfied requests + (Tolerating reauests/2)/ Total number of requests


During a 2 minute period a server handles 200 requests.

The threshold T = 0.5 seconds (500ms). This value is arbitrary and is selected by the user.

170 of the requests were handled within 500ms, so they are classified as Satisfied.

20 of the requests were handled between 500ms and 2 seconds (2000 ms), so they are classified as Tolerating.

The remaining 10 were not handled properly or took longer than 2 seconds, so they are classified as Frustrated.

The resulting Apdex score is 0.9: (170 + (20/2))/200 = 0.9.


This is another company which has good tools for measuring app performance,web site performance,server monitoring etc.


Uptrends is powerful website monitoring tool, while it is not in the same league as an APM it is still a good tool for monitoring web application performance.

These writings represent my own personal views alone.
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