Introduction to Application Center Test (ACT)

Introduction

Developers Concentrate on new features to make their job simple. Of course the aim of the New Versions of Visual studio is to make Developer job easy by reducing code more than half of previous versions. Developers look for Code to meet their Client requirement .Most of them least bother about the internal processing of Web server (IIS).This article is to make the developers to check their Application's Performance using Microsoft Application Center Test Tool (ACT).

Description

As a developer, It is need to know about Microsoft's Stress testing tool for Visual studio 2003, Application Center Test (ACT) stress tests web servers and analyzes performance and scalability problems with web applications. By this tool we can measure application performance through several parameters like Requests per Second (RPS), Iterations, HTTP errors, DNS errors, Socket errors, Average Time to first byte, Average Time to last byte etc. This parameters list Displayed on Output window after completion of test. This test also useful to check the behavior of the application under several simultaneous end users (load) of the web applications.

Parameters Information

• Requests per Second: Indicates the rate at which the Web server is responding to HTTP requests from ACT. Values are calculated based on a one second sampling period.

Note: It should be high.

Iterations: Indicates the number of times the test has iterated(looped) since the start of the test run. This is displayed for all tests, regardless of whether the test duration was specified using iterations or a run time.

Note: It should be high.

• HTTP errors: Indicates response codes in the 400-499 and 500-599 range are being received. These errors can be caused by many different problems with either the requests or the Web application. Examine the report to find the requests responsible for the errors, and the exact response codes returned by the Web server.
• DNS errors: Indicates errors occurred resolving the server's address. It could be caused by a request that uses an invalid server name, or it could be due to network configuration problems.
• Socket errors: Indicates the Web server is unable to maintain some or all connections. During intense load conditions using multiple simultaneous connections, the Web server will usually begin rejecting connections after its maximum capacity is exceeded.

Note: No Errors (HTTP/Socket/DNS) should appear.

• Average Time to first byte (TTFB): Measures server responsiveness. TTFB is the time between sending the request, and receiving the first part of the Web server's response stream.

Note: It should be less.

• Average Time to last byte (TTLB): Measures server responsiveness. TTLB is the time between sending the request, and receiving the end of the Web server's response stream.

Note: It should be less.

Installation:

If you have VS-2003 in your system, we can work on ACT. No additional Installations needed.

Conclusion:

Performance is an after thought. Obviously after the correctness of the application. But we can't ignore the Performance. Using ACT we can assess the Application performance, Not the suggestions to improve application performance. My next article will be on "tips to improve Performance of Web applications"