log stack trace when HTTP request return error in Jmeter

Question

I want to log all error message for failed HTTP request. I am going to run the thread group for 1B users and I don't want to use the View Result Tree because it logs everything and log file will bloat.
Currently I am using Beanshell Assertion as below.

if (Boolean.valueOf(vars.get("DEBUG"))) {

  if (ResponseCode.equals("200") == false) {
     log.info(SampleResult.getResponseMessage());
  log.info("There was some problem");
  }
}

But in this case it just prints the error message but I am interested to log the stack trace returned by the server.

I also used this method as mention in this thread

for (a: SampleResult.getAssertionResults()) {
   if (a.isError() || a.isFailure()) {
     log.error(Thread.currentThread().getName()+": "+SampleLabel+": Assertion failed for response: " + new String((byte[]) ResponseData));
   }
}

But in this case I don't get an object out of SampleResult.getAssertionResults() method and it doesn't display anything in case of HTTP request failure.

Any idea how to get the stacK trace?

Answer 1

I figured it out. SampleResult has one more method called getResponseDataAsString(). This method returns the response message. In case of error it contains the error message.