title: jmeter give an error No buffer space available (maximum connections reached?): connect
body: <pre><code>Number of threads = 20 
  Ramp-up period = 10 
  Loop count = 200
  </code></pre>
  
  <p>gives an error after some time: </p>
  
  <pre><code>java.net.SocketException: No buffer space available (maximum connections reached?): connect
      at java.net.PlainSocketImpl.socketConnect(Native Method)
      at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
      at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
      at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
      at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
      at java.net.Socket.connect(Socket.java:529)
      at java.net.Socket.connect(Socket.java:478)
      at sun.net.NetworkClient.doConnect(NetworkClient.java:163)
      at sun.net.www.http.HttpClient.openServer(HttpClient.java:395)
      at sun.net.www.http.HttpClient.openServer(HttpClient.java:530)
      at sun.net.www.http.HttpClient.&lt;init&gt;(HttpClient.java:234)
      at sun.net.www.http.HttpClient.New(HttpClient.java:307)
      at sun.net.www.http.HttpClient.New(HttpClient.java:324)
      at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:970)
      at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:911)
      at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:836)
      at org.apache.jmeter.protocol.http.sampler.HTTPJavaImpl.sample(HTTPJavaImpl.java:483)
      at org.apache.jmeter.protocol.http.sampler.HTTPSamplerProxy.sample(HTTPSamplerProxy.java:62)
      at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1018)
      at org.apache.jmeter.protocol.http.sampler.HTTPSamplerBase.sample(HTTPSamplerBase.java:1004)
      at org.apache.jmeter.threads.JMeterThread.process_sampler(JMeterThread.java:411)
      at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:297)
      at java.lang.Thread.run(Thread.java:662)
  </code></pre>