title: Java.net.SocketException connection reset error in .net application
body: <p>We have a n-tier (.net) web application where we have a Web tier -> App tier -> Database. </p>
  
  <p>Everything worked fine until we went for load testing (using jmeter). <strong>When we simulated 100 concurrent users, after 3 -4 min. jmeter started logging SocketException, connection reset</strong>. When we checked application logs (we logs all the exceptions inside application) and system events, we could not find anything.</p>
  
  <p>We have not taken any special measures for performance on web tier. But on App tier which is a wcf application, we have used per-call/multiple concurrency. We have used following configuration on app tier:</p>
  
  <pre><code>        &lt;serviceThrottling
             maxConcurrentCalls     = "200"
             maxConcurrentSessions  = "200"
             maxConcurrentInstances = "200"/&gt;
  </code></pre>
  
  <p>.
  .
  .</p>
  
  <pre><code>    &lt;binding name="defaultNetTcpBinding" closeTimeout="00:10:00" sendTimeout="00:10:00" receiveTimeout="00:10:00" openTimeout="00:10:00" maxReceivedMessageSize="2147483647" maxBufferPoolSize="2147483647"
               maxConnections="200" listenBacklog="200"&gt;
  </code></pre>
  
  <p><strong>Apart from this issue, our App tier usage is also on higher side (50-60%). Following are the configuration of our 3 VMs (one for each tier)</strong></p>
  
  <p><strong>Web Server (Quantity = 1)</strong>   Processor   Intel Xeon CPU X5675 @3.07 GHz  2.19 GHz</p>
  
  <pre><code>Number of Cores (Virtual)   8
  
  RAM 8GB
  
  Operating System    Windows Sever 2012 Standard
  
  Processor Type  64 Bit
  
  Softwares Installed NET Framework 4.5
  </code></pre>
  
  <p><strong>App Server (Quantity = 1)</strong>
      Processor   Intel Xeon CPU X5675 @3.07 GHz  3.07 GHz</p>
  
  <pre><code>Number of Cores (Virtual)   8
  
  RAM 8GB
  
  Operating System    Windows Sever 2012 Standard
  
  Processor Type  64 Bit
  
  Softwares Installed NET Framework 4.5
  </code></pre>
  
  <p><strong>DB Server (Quantity =1)</strong> 
  Processor   Intel Xeon CPU E7-4830v2  @ 2.20 GHz  2.19 GHz</p>
  
  <pre><code>Number of Cores (Virtual)   8
  
  RAM 8GB
  
  Operating System    Windows Sever 2012 Standard
  
  Processor Type  64 Bit
  
  Softwares Installed Microsoft SQL Sever 2014
  </code></pre>