@Test
  public void testNormalOperation() throws Exception {
    int conns = 5;

    // create connections
    ArrayList<String> connectionIds = new ArrayList<String>();
    for (int i = 0; i < conns; i++) {
      connectionIds.add(blockingSSLConnect(DEFAULT_SOCKET_BUF_SIZE));
    }

    // send echo requests and receive responses
    int responseCount = 0;
    List<NetworkSend> sends = new ArrayList<NetworkSend>();
    for (int i = 0; i < conns; i++) {
      String connectionId = connectionIds.get(i);
      sends.add(SelectorTest.createSend(connectionId, connectionId + "&" + 0));
    }

    // loop until we complete all requests
    while (responseCount < conns) {
      // do the i/o
      selector.poll(0L, sends);
      Thread.sleep(100);

      assertEquals("No disconnects should have occurred.", 0, selector.disconnected().size());

      // handle any responses we may have gotten
      for (NetworkReceive receive : selector.completedReceives()) {
        ByteBuf payload = receive.getReceivedBytes().content();
        String[] pieces = SelectorTest.asString(payload).split("&");
        assertEquals("Should be in the form 'conn-counter'", 2, pieces.length);
        assertEquals("Check the source", receive.getConnectionId(), pieces[0]);
        assertTrue("Received connectionId is as expected ", connectionIds.contains(receive.getConnectionId()));
        assertEquals("Check the request counter", 0, Integer.parseInt(pieces[1]));
        responseCount++;
        receive.getReceivedBytes().release();
      }

      // prepare new sends for the next round
      sends.clear();
      for (NetworkSend send : selector.completedSends()) {
        String dest = send.getConnectionId();
        sends.add(SelectorTest.createSend(dest, dest + "&" + 0));
      }
    }
  }
Send multiple requests to several connections in parallel. Validate that responses are received in the order that
requests were sent.
ambry-network/src/test/java/com/github/ambry/network/SSLSelectorTest.java