@Test
  public void testProcessHeartbeat() throws Exception {
    TestGeneratorInputOperator o1 = dag.addOperator("o1", TestGeneratorInputOperator.class);
    dag.setAttribute(
        o1,
        OperatorContext.STATS_LISTENERS,
        Arrays.asList(new StatsListener[] {new PartitioningTest.PartitionLoadWatch()}));
    dag.setAttribute(OperatorContext.STORAGE_AGENT, new MemoryStorageAgent());

    StreamingContainerManager scm = new StreamingContainerManager(dag);
    PhysicalPlan plan = scm.getPhysicalPlan();
    Assert.assertEquals("number required containers", 1, plan.getContainers().size());

    PTOperator o1p1 = plan.getOperators(dag.getMeta(o1)).get(0);

    // assign container
    String containerId = "container1";
    StreamingContainerAgent sca =
        scm.assignContainer(
            new ContainerResource(0, containerId, "localhost", 512, 0, null),
            InetSocketAddress.createUnresolved("localhost", 0));
    Assert.assertNotNull(sca);

    Assert.assertEquals(PTContainer.State.ALLOCATED, o1p1.getContainer().getState());
    Assert.assertEquals(PTOperator.State.PENDING_DEPLOY, o1p1.getState());

    ContainerStats cstats = new ContainerStats(containerId);
    ContainerHeartbeat hb = new ContainerHeartbeat();
    hb.setContainerStats(cstats);

    ContainerHeartbeatResponse chr = scm.processHeartbeat(hb); // get deploy request
    Assert.assertNotNull(chr.deployRequest);
    Assert.assertEquals("" + chr.deployRequest, 1, chr.deployRequest.size());
    Assert.assertEquals(PTContainer.State.ACTIVE, o1p1.getContainer().getState());
    Assert.assertEquals("state " + o1p1, PTOperator.State.PENDING_DEPLOY, o1p1.getState());

    // first operator heartbeat
    OperatorHeartbeat ohb = new OperatorHeartbeat();
    ohb.setNodeId(o1p1.getId());
    ohb.setState(OperatorHeartbeat.DeployState.ACTIVE);
    OperatorStats stats = new OperatorStats();
    stats.checkpoint = new Checkpoint(2, 0, 0);
    stats.windowId = 3;

    stats.outputPorts = Lists.newArrayList();
    PortStats ps = new PortStats(TestGeneratorInputOperator.OUTPUT_PORT);
    ps.bufferServerBytes = 101;
    ps.tupleCount = 1;
    stats.outputPorts.add(ps);

    ohb.windowStats = Lists.newArrayList(stats);
    cstats.operators.add(ohb);
    scm.processHeartbeat(hb); // activate operator

    Assert.assertEquals(PTContainer.State.ACTIVE, o1p1.getContainer().getState());
    Assert.assertEquals("state " + o1p1, PTOperator.State.ACTIVE, o1p1.getState());

    Assert.assertEquals("tuples " + o1p1, 1, o1p1.stats.totalTuplesEmitted.get());
    Assert.assertEquals("tuples " + o1p1, 0, o1p1.stats.totalTuplesProcessed.get());
    Assert.assertEquals("window " + o1p1, 3, o1p1.stats.currentWindowId.get());

    Assert.assertEquals("port stats", 1, o1p1.stats.outputPortStatusList.size());
    PortStatus o1p1ps = o1p1.stats.outputPortStatusList.get(TestGeneratorInputOperator.OUTPUT_PORT);
    Assert.assertNotNull("port stats", o1p1ps);
    Assert.assertEquals("port stats", 1, o1p1ps.totalTuples);

    // second operator heartbeat
    stats = new OperatorStats();
    stats.checkpoint = new Checkpoint(2, 0, 0);
    stats.windowId = 4;

    stats.outputPorts = Lists.newArrayList();
    ps = new PortStats(TestGeneratorInputOperator.OUTPUT_PORT);
    ps.bufferServerBytes = 1;
    ps.tupleCount = 1;
    stats.outputPorts.add(ps);

    ohb.windowStats = Lists.newArrayList(stats);
    cstats.operators.clear();
    cstats.operators.add(ohb);
    scm.processHeartbeat(hb);

    Assert.assertEquals("tuples " + o1p1, 2, o1p1.stats.totalTuplesEmitted.get());
    Assert.assertEquals("window " + o1p1, 4, o1p1.stats.currentWindowId.get());
    Assert.assertEquals("statsQueue " + o1p1, 2, o1p1.stats.listenerStats.size());

    scm.processEvents();
    Assert.assertEquals("statsQueue " + o1p1, 0, o1p1.stats.listenerStats.size());
    Assert.assertEquals("lastStats " + o1p1, 2, o1p1.stats.lastWindowedStats.size());
  }