Exemplo n.º 1
0
    private void sendAck() {
      // Send results back
      DTask dt, origDt = _dt; // _dt can go null the instant it is send over wire
      assert origDt != null; // Freed after completion
      while ((dt = _dt) != null) { // Retry loop for broken TCP sends
        AutoBuffer ab = null;
        try {
          // Start the ACK with results back to client.  If the client is
          // asking for a class/id mapping (or any job running at FETCH_ACK
          // priority) then return a udp.fetchack byte instead of a udp.ack.
          // The receiver thread then knows to handle the mapping at the higher
          // priority.

          UDP.udp udp = dt.priority() == H2O.FETCH_ACK_PRIORITY ? UDP.udp.fetchack : UDP.udp.ack;
          ab = new AutoBuffer(_client, udp._prior).putTask(udp, _tsknum).put1(SERVER_UDP_SEND);
          assert ab.position() == 1 + 2 + 4 + 1;
          dt.write(ab); // Write the DTask - could be very large write
          dt._repliedTcp = ab.hasTCP(); // Resends do not need to repeat TCP result
          ab.close(); // Then close; send final byte
          _computedAndReplied = true; // After the final handshake, set computed+replied bit
          break; // Break out of retry loop
        } catch (AutoBuffer.AutoBufferException e) {
          if (!_client._heartbeat._client) // Report on servers only; clients allowed to be flaky
          Log.info(
                "IOException during ACK, "
                    + e._ioe.getMessage()
                    + ", t#"
                    + _tsknum
                    + " AB="
                    + ab
                    + ", waiting and retrying...");
          ab.drainClose();
          if (_client._heartbeat._client) // Dead client will not accept a TCP ACK response?
          this.CAS_DT(dt, null); // cancel the ACK
          try {
            Thread.sleep(100);
          } catch (InterruptedException ignore) {
          }
        } catch (Exception e) { // Custom serializer just barfed?
          Log.err(e); // Log custom serializer exception
          ab.drainClose();
        }
      } // end of while(true)
      if (dt == null)
        Log.info(
            "Cancelled remote task#"
                + _tsknum
                + " "
                + origDt.getClass()
                + " to "
                + _client
                + " has been cancelled by remote");
      else {
        if (dt instanceof MRTask && dt.logVerbose())
          Log.debug("Done remote task#" + _tsknum + " " + dt.getClass() + " to " + _client);
        _client.record_task_answer(this); // Setup for retrying Ack & AckAck, if not canceled
      }
    }
Exemplo n.º 2
0
  // Handle TCP traffic, from a client to this server asking for work to be
  // done.  This is called on the TCP reader thread, not a Fork/Join worker
  // thread.  We want to do the bulk TCP read in the TCP reader thread.
  static void tcp_exec(final AutoBuffer ab) {
    final int ctrl = ab.getCtrl();
    final int task = ab.getTask();
    final int flag = ab.getFlag();
    assert flag == CLIENT_UDP_SEND; // Client sent a request to be executed?
    // Act "as if" called from the UDP packet code, by recording the task just
    // like the packet we will be receiving (eventually).  The presence of this
    // packet is used to stop dup-actions on dup-sends.  Racily inserted, keep
    // only the last one.
    DTask dt1 = ab._h2o.record_task(task);
    assert dt1 == null || dt1 instanceof NOPTask
        : "#"
            + task
            + " "
            + dt1.getClass(); // For TCP, no repeats, so 1st send is only send (except for UDP
    // timeout retries)

    // Make a remote instance of this dude from the stream, but only if the
    // racing UDP packet did not already make one.  Start the bulk TCP read.
    final DTask dt = ab.get(DTask.class);

    // Here I want to execute on this, but not block for completion in the
    // TCP reader thread.  Jam the task on some F/J thread.
    UDP.udp
        .UDPS[ctrl]
        .pool()
        .execute(
            new CountedCompleter() {
              public void compute() {
                remexec(dt, ab._h2o, task, ab).close();
                tryComplete();
              }

              public boolean onExceptionalCompletion(Throwable ex, CountedCompleter caller) {
                ex.printStackTrace();
                return true;
              }
            });
    // All done for the TCP thread!  Work continues in the FJ thread...
  }
Exemplo n.º 3
0
 // Re-send strictly the ack, because we're missing an AckAck
 final void resend_ack() {
   assert _computedAndReplied : "Found RPCCall not computed " + _tsknum;
   DTask dt = _dt;
   if (dt == null) return; // Received ACKACK already
   UDP.udp udp = dt.priority() == H2O.FETCH_ACK_PRIORITY ? UDP.udp.fetchack : UDP.udp.ack;
   AutoBuffer rab = new AutoBuffer(_client, dt.priority()).putTask(udp, _tsknum);
   boolean wasTCP = dt._repliedTcp;
   if (wasTCP) rab.put1(RPC.SERVER_TCP_SEND); // Original reply sent via TCP
   else {
     rab.put1(RPC.SERVER_UDP_SEND); // Original reply sent via UDP
     assert rab.position() == 1 + 2 + 4 + 1;
     dt.write(rab);
   }
   assert sz_check(rab)
       : "Resend of " + _dt.getClass() + " changes size from " + _size + " to " + rab.size();
   assert dt._repliedTcp == wasTCP;
   rab.close();
   dt._repliedTcp = wasTCP;
   // Double retry until we exceed existing age.  This is the time to delay
   // until we try again.  Note that we come here immediately on creation,
   // so the first doubling happens before anybody does any waiting.  Also
   // note the generous 5sec cap: ping at least every 5 sec.
   _retry += (_retry < MAX_TIMEOUT) ? _retry : MAX_TIMEOUT;
 }