title: com.sun.HttpServer socket backlog
body: <p>What does socket backlog mean?</p>
  
  <p>for example I have web service </p>
  
  <pre><code>@WebService
  public class Calculator {
  public int sum(int a, int b) {
      try {
          Thread.sleep(1000);
      } catch (InterruptedException e) {
          e.printStackTrace();
      }
      return a + b;
  }
  
  public static final int threadCount = 10;
  
  public static void main(String[] args) throws IOException {
      Executor manyThreads = Executors.newFixedThreadPool(threadCount);
      HttpServer server = HttpServer.create(new InetSocketAddress(8989), threadCount);
      server.setExecutor(manyThreads);
      server.start();
  
      Endpoint ep = Endpoint.create(new Calculator());
      HttpContext context = server.createContext("/calc");
      ep.publish(context);
  }
  }
  </code></pre>
  
  <p>and webservice client</p>
  
  <pre><code> public static void main(String[] args) throws IOException {
      CalculatorService service = new CalculatorService();
      final Calculator calc = service.getCalculatorPort();
  
      Executor executor = Executors.newFixedThreadPool(100);
  
      for (int i = 0; i &lt; 1000000; ++i) {
          executor.execute(new Runnable() {
              public void run() {
                  try {
                      int currentThreads = runningThreads.incrementAndGet();
                      int res = calc.sum(10, 10);
                      System.out.println("Running threads: " + currentThreads + " Result: " + res);
                  } catch (ClientTransportException e) {
                      System.out.println("connection refused");
                  } finally {
                      runningThreads.decrementAndGet();
                  }
              }
          });
      }
  
      System.in.read();
  }
  </code></pre>
  
  <p>on the server only 10 working threads and backlog is set to 10, so there can be 10 accepted connections and 10 connections that are waiting in backlog and any other connection will be refused, am I right?</p>
  
  <p>May be not as I don't get ClientTransportException.</p>
  
  <p>Could you give me explanation what is happening with connections and why there is no ClientTransportException.</p>