title: JMeter to ignore warmup period
body: <p>Contrary to <a href="https://stackoverflow.com/questions/32237837/how-to-exclude-warmup-time-from-jmeter-summary">How to exclude warmup time from JMeter summary?</a>, as I don't want to spin up 20 threads all at once. Instead,</p>
  <p>I want to ignore a certain warmup period (or a certain iterations), to exclude the initial visit outliers, illustrated clearly in the following chart:</p>
  <p><a href="https://i.stack.imgur.com/r4Uuu.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/r4Uuu.png" alt="enter image description here" /></a></p>
  <p>Very close to <a href="https://stackoverflow.com/questions/54782334/jmeter-structure-warmup">JMeter structure warmup</a>, however, not specifically to <em>&quot;a child of the request you want to ignore&quot;</em>. I.e., I want to apply to all samplers/requests for all threads.</p>
  <p>So instead of &quot;Add JSR223 PostProcessor as a child of the request you want to ignore&quot;, I need to add a generic JSR223 PostProcessor at thread group level to control all samplers/requests. Is that possile? If so, how should I do? I remember that the JSR223 code should mention <code>parent()</code> or something like that.</p>