title: get NoHttpResponseException for load testing
body: <p>I'm running load tests for my application. I have two servers: one with my application and a dummy-server that is responsible to get me responses.</p>
  
  <p>In my dummy server I have the following jsp code:</p>
  
  <pre><code>&lt;%@ page import="java.util.Random" %&gt;
  &lt;%@ page language="java" %&gt;
  &lt;%@ page session="false" %&gt;
  &lt;%
     String retVal = "some json string";
     Thread.sleep(50);
  %&gt;
  </code></pre>
  
     
  
  <p>I'm running the application with tomcat7. My server.xml connection pool (in both servers) looks like:</p>
  
  <pre><code>&lt;Executor name="tomcatThreadPool" namePrefix="catalina-exec-" maxThreads="1500" minSpareThreads="1000" prestartminSpareThreads="true" /&gt; 
  &lt;Connector port="9031" protocol="HTTP/1.1" 
             connectionTimeout="20000" 
             maxConnections="4000"
             executor="tomcatThreadPool"
             redirectPort="8443" /&gt;
  </code></pre>
  
  <p>The java code I'm running from the servers is:</p>
  
  <pre><code> HttpPost post = new HttpPost(bidderUrl);
   post.setHeader("Content-Type", "application/json");    
   // I'm using http client with ThreadSafeClientConnManager
   // total conn = 500,  max conn per route = 100, timeout=500millis
   HttpClient httpClient = httpClientFactory.getHttpClient();
      try {
          post.setEntity(new StringEntity(jsobBidRequest));
          HttpResponse response = httpClient.execute(post);
          ...
      catch (NoHttpResponseException e){
          log.error(e);
      }
  </code></pre>
  
  <p>I'm running Jmetter with 50 concurrent threads (without a loop) and get a lot of exceptions like this:</p>
  
  <pre><code>org.apache.http.NoHttpResponseException The target server failed to respond 
  </code></pre>
  
  <p>While I'm running just 5 or 10 concurrent threads everything works ok. </p>
  
  <p>Could you please advice me what could be wrong in my setup? For my understanding, I don't see any errors for the 50 concurrent thread requests.</p>