title: Jmeter http requests get 400 response code in some random thread
body: <p>I wrote an test plan by using JMeter. it's structured like this: </p>
  
  <p>Thread Group </p>
  
  <ul>
  <li>HTTP Cache Manager</li>
  <li>HTTP Cookie Manager</li>
  <li>CSV Data Set Config</li>
  <li>CSV Data Set Config</li>
  <li>Index Page
  <ul>
  <li>a few Http requests</li>
  </ul></li>
  <li>Random Order Controller
  <ul>
  <li>a few Http requests</li>
  </ul></li>
  <li>login page
  <ul>
  <li>a few Http requests</li>
  <li>Random Order Controller</li>
  <li>a few Http requests</li>
  <li>Throughput Controller</li>
  <li>a few Http requests</li>
  </ul></li>
  <li>Simple Controller
  <ul>
  <li>a few Http requests</li>
  </ul></li>
  <li>View Results Tree</li>
  </ul>
  
  <p>I run 50 threads, however, some random http request fails with "Response code:400" in a thread, but it's successful for in other threads. </p>
  
  <p>So I'm don't know how to investigate on this, as it works fine sometimes but it fails once or twice. </p>
  
  <p>Can anyone give me some suggestions? I will really appreciate with your help.</p>