Почему HttpServer обрабатывает только 4 запроса одновременно? - PullRequest
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Почему HttpServer обрабатывает только 4 запроса одновременно?

0 голосов
/ 15 апреля 2019

Я новичок в программировании на Java. HttpRequest может обрабатывать только <= 4 запросов одновременно, даже если для <code>newFixedThreadPool установлено значение 28.

  • Я пытался использовать newCachedThreadPool, но даже это обрабатывает 4 запроса одновременно.
  • Если я установлю newFixedThreadPool на 3, это будет хорошо. 
server = HttpServer.create(new InetSocketAddress(port), 0);
server.createContext("/", new MyHandler());
server.setExecutor(Executors.newFixedThreadPool(28)); // creates a default executor
ThreadPoolExecutor t = (ThreadPoolExecutor)server.getExecutor();
LOG.info("Pool size " + t.getPoolSize() + " Max Pool size " + t.getMaximumPoolSize() + " Largest pool size " + t.getLargestPoolSize() + " Core pool size " + t.getCorePoolSize() + " actively executing threads " + t.getActiveCount() + " Completed task count " + t.getCompletedTaskCount() + " task count " + t.getTaskCount());
server.start();

  static class MyHandler implements HttpHandler {
      public void handle(HttpExchange t) throws IOException {
        try{
          long threadId = Thread.currentThread().getId();
          ThreadPoolExecutor t1 = (ThreadPoolExecutor)server.getExecutor();
          LOG.info("Thread #" + threadId + " before : Pool size " + t1.getPoolSize() + " Max Pool size " + t1.getMaximumPoolSize() + " Largest pool size " + t1.getLargestPoolSize() + " Core pool size " + t1.getCorePoolSize() + " actively executing threads " + t1.getActiveCount() + " Completed task count " + t1.getCompletedTaskCount() + " task count " + t1.getTaskCount());
          LOG.info("Received request on thread #" + threadId);
          String response = h.processRequest(t.getRequestURI().toString());
          t.sendResponseHeaders(200, response.length());
          OutputStream os = t.getResponseBody();
          os.write(response.getBytes());
          os.close();
          LOG.info("Request processed on thread #" + threadId);
          LOG.info("Thread #" + threadId + " after : Pool size " + t1.getPoolSize() + " Max Pool size " + t1.getMaximumPoolSize() + " Largest pool size " + t1.getLargestPoolSize() + " Core pool size " + t1.getCorePoolSize() + " actively executing threads " + t1.getActiveCount() + " Completed task count " + t1.getCompletedTaskCount() + " task count " + t1.getTaskCount());
        } catch (Exception e) {
          LOG.warn("Exception. ", e);
        }
      }
  }

public String processRequest(String req)
{
   Thread.sleep(5000);
}

Выход журнала 

19/04/15 16:26:07 : Thread #99 before : Pool size 21 Max Pool size 28 Largest pool size 21 Core pool size 28 actively executing threads 1 Completed task count 20 task count 21
19/04/15 16:26:07 : Received request on thread #99
19/04/15 16:26:07 : Inside Handler Sr. No [1]
19/04/15 16:26:07 : Thread #100 before : Pool size 22 Max Pool size 28 Largest pool size 22 Core pool size 28 actively executing threads 2 Completed task count 20 task count 22
19/04/15 16:26:07 : Received request on thread #100
19/04/15 16:26:07 : Inside Handler Sr. No [2]
19/04/15 16:26:08 : Thread #101 before : Pool size 23 Max Pool size 28 Largest pool size 23 Core pool size 28 actively executing threads 3 Completed task count 20 task count 23
19/04/15 16:26:08 : Received request on thread #101
19/04/15 16:26:08 : Inside Handler Sr. No [3]
19/04/15 16:26:08 : Thread #102 before : Pool size 24 Max Pool size 28 Largest pool size 24 Core pool size 28 actively executing threads 4 Completed task count 20 task count 24
19/04/15 16:26:08 : Received request on thread #102
19/04/15 16:26:08 : Inside Handler Sr. No [4]
19/04/15 16:26:12 : Request processed on thread #99
19/04/15 16:26:12 : Thread #99 after : Pool size 24 Max Pool size 28 Largest pool size 24 Core pool size 28 actively executing threads 4 Completed task count 20 task count 24
19/04/15 16:26:12 : Thread #103 before : Pool size 25 Max Pool size 28 Largest pool size 25 Core pool size 28 actively executing threads 4 Completed task count 21 task count 25
19/04/15 16:26:12 : Received request on thread #103
19/04/15 16:26:12 : Inside Handler Sr. No [5]
19/04/15 16:26:12 : Request processed on thread #100
19/04/15 16:26:12 : Thread #100 after : Pool size 25 Max Pool size 28 Largest pool size 25 Core pool size 28 actively executing threads 4 Completed task count 21 task count 25
19/04/15 16:26:12 : Thread #104 before : Pool size 26 Max Pool size 28 Largest pool size 26 Core pool size 28 actively executing threads 4 Completed task count 22 task count 26
19/04/15 16:26:12 : Received request on thread #104
19/04/15 16:26:12 : Inside Handler Sr. No [6]
19/04/15 16:26:13 : Request processed on thread #101
19/04/15 16:26:13 : Thread #101 after : Pool size 26 Max Pool size 28 Largest pool size 26 Core pool size 28 actively executing threads 4 Completed task count 22 task count 26
19/04/15 16:26:13 : Thread #105 before : Pool size 27 Max Pool size 28 Largest pool size 27 Core pool size 28 actively executing threads 4 Completed task count 23 task count 27
19/04/15 16:26:13 : Received request on thread #105
19/04/15 16:26:13 : Inside Handler Sr. No [7]
19/04/15 16:26:13 : Request processed on thread #102
19/04/15 16:26:13 : Thread #102 after : Pool size 27 Max Pool size 28 Largest pool size 27 Core pool size 28 actively executing threads 4 Completed task count 23 task count 27
19/04/15 16:26:13 : Thread #106 before : Pool size 28 Max Pool size 28 Largest pool size 28 Core pool size 28 actively executing threads 4 Completed task count 24 task count 28
19/04/15 16:26:13 : Received request on thread #106
19/04/15 16:26:13 : Inside Handler Sr. No [8]
19/04/15 16:26:17 : Request processed on thread #103
19/04/15 16:26:17 : Thread #103 after : Pool size 28 Max Pool size 28 Largest pool size 28 Core pool size 28 actively executing threads 4 Completed task count 24 task count 28
19/04/15 16:26:17 : Thread #24 before : Pool size 28 Max Pool size 28 Largest pool size 28 Core pool size 28 actively executing threads 4 Completed task count 25 task count 29
19/04/15 16:26:17 : Received request on thread #24
19/04/15 16:26:17 : Inside Handler Sr. No [9]
19/04/15 16:26:17 : Request processed on thread #104
19/04/15 16:26:17 : Thread #104 after : Pool size 28 Max Pool size 28 Largest pool size 28 Core pool size 28 actively executing threads 4 Completed task count 25 task count 29

Почему он обрабатывает только 4 запроса одновременно? Я что-то не так делаю?

Спасибо

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