Archive for September, 2012|Monthly archive page

Tips to Create High Performing Scripts in LoadRunner

 

More often not when we are load testing, our focus is generally on optimizing the application code. However, are we sure the scripts we are scripting in LoadRunner are optimal and they are not contributing to latency? Here are few tips that can help in keeping the memory footprint of loadrunner less.

  • Keep it simple

Like most things in life, try keeping the complexity of the scripts as simple as possible. Basic theme is to ensure minimal memory footprint. Ideally, a newbie should be able to understand the script without presence of any extensive comments. One method is to have one script corresponding to a single business process. This can become cumbersome when the number of business processes is more resulting in huge number of scripts. On the other hand if there a complex business process, it does make sense to break it down into multiple scripts.

  • Pointers

How we love them when we understand them! In an ideal scenario, pointers should help in reducing the memory footprint. However, memory management is manual in C and we are never sure how the memory is being allocated. Best way of using a pointer is to avoid them as far as possible.

  • Custom Code and Custom Functions

All our programming lives, we have been taught to make things automated so that we create an abstract layer that user understands and hide the complex code beneath it. Moreover, reusability has always been drummed into us from the time we started printing “Hello World!” Yet when we are load testing, each line of custom code or custom function adds precious CPU cycles to your load testing.  Avoid them as far as possible.

  • LoadRunner extended library & Parametrization feature

LoadRunner has extended C library in a big way. Use of these functions is recommended as these functions have been tested for speed and is reliable to a large extent. These functions help in reducing the custom code and thus help in reducing complex coding.

Parametrization – Like most tools, LoadRunner has extensive options for parameterization and if used creatively can result in very simple solutions for some complex problems that are generally faced.

  • Reuse Variables

Try reusing the defined variables again and again. Loop counters are a prime example for this. The more variables defined, the more memory it will consume.   Keeping variables local as far as possible can also help in minimizing the memory footprint. When declaring arrays, ensure the size is optimal. For example, if a name is supposed to take 20 characters, having an array of 30 characters will not impact much. However, if array size is set for 100 characters for the same, then it becomes a problem.

This is primarily for testing of web applications using loadrunner. Do share your thoughts and other options of improving the scripts in the comment section! Will be all ears for it or should I say eyes for it:)

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