3

I need to read file once and its result to be processed further in sampler. My strategy is ThreadGroup--> BeanShell Preprocessor + BeanShell Sampler

My preprocessor should read file once for whole Thread Group and result to be used in Sampler for specific no. of thread.(i do not want to read file for each thread)

I wrote file reader code in preprocessor, now need to use the result in sampler.

usman
  • 1,351
  • 5
  • 23
  • 47

2 Answers2

3
  1. Don't use the Beanshell PreProcessor as it will be executed by each thread. Use a separate Thread Group with 1 thread to read the values.
  2. Don't use Beanshell Samplers to create the actual load, in case of more or less severe load it will become a bottleneck.
  3. Use JSR223 Test Elements and "groovy" language for scripting - this way you'll be able to get maximum performance from your code.

Now answers:

int number = ctx.getThread().getThreadNum(); // get current thread number

props.put("value_for_thread_" + number, "foo"); // store some value specific for the specific thread

String value = props.get("value_for_thread_5"); // get value for thread 5

Where:

  • ctx - is a shorthand for JMeterContext
  • props - stands for JMeter Properties, an instance of java.util.Properties deriving all the methods and fields, global for the whole JVM instance.

See JavaDocs for aforementioned objects to see what else can be done and Beanshell vs JSR223 vs Java JMeter Scripting: The Performance-Off You've Been Waiting For! guide for instructions on installing groovy scripting engine, scripting best practices and benchmark of Beanshell, JSR223+groovy and Java code.

Dmitri T
  • 159,985
  • 5
  • 83
  • 133
1

Use Jmeter variables to store the values you've read, and then use them in subsequent steps. Please note that the pre-processor will run every time your thread loop is executed.

In your beanshell preprocessor, you can store a variable like this:

vars.put("name","value")

and then access it later either as 

vars.get("name")

in beanshell, or as ${name} in fields of any other sampler.

Please note that if your preprocessor is part of your main thread group, it will be run every time your thread loops. If this is an expensive operation or values do not change during the run, you might want to use a setup thread group.

RaGe
  • 22,696
  • 11
  • 72
  • 104