Java 类com.amazonaws.services.cloudwatch.model.GetMetricStatisticsResult 实例源码

private double getInstanceAverageLoad(AmazonCloudWatchClient cloudWatchClient, String instanceId) {

        long offsetInMilliseconds = 1000 * 60 * 60;
        GetMetricStatisticsRequest request = new GetMetricStatisticsRequest()
                .withStartTime(new Date(new Date().getTime() - offsetInMilliseconds))
                .withNamespace("AWS/EC2")
                .withPeriod(60 * 60)
                .withDimensions(new Dimension().withName("InstanceId").withValue(instanceId))
                .withMetricName("CPUUtilization")
                .withStatistics("Average", "Maximum")
                .withEndTime(new Date());
        GetMetricStatisticsResult getMetricStatisticsResult = cloudWatchClient.getMetricStatistics(request);

        double avgCPUUtilization = 0;
        List dataPoint = getMetricStatisticsResult.getDatapoints();
        for (Object aDataPoint : dataPoint) {
            Datapoint dp = (Datapoint) aDataPoint;
            avgCPUUtilization = dp.getAverage();
        }

        return avgCPUUtilization;
    }

/**
 * Gets total size in bytes of all events that remain in Kinesis stream between specified
 * instants.
 *
 * @return total size in bytes of all Kinesis events after specified instant
 */
public long getBacklogBytes(final String streamName, final Instant countSince,
    final Instant countTo) throws TransientKinesisException {
  return wrapExceptions(new Callable<Long>() {

    @Override
    public Long call() throws Exception {
      Minutes period = Minutes.minutesBetween(countSince, countTo);
      if (period.isLessThan(Minutes.ONE)) {
        return 0L;
      }

      GetMetricStatisticsRequest request = createMetricStatisticsRequest(streamName,
          countSince, countTo, period);

      long totalSizeInBytes = 0;
      GetMetricStatisticsResult result = cloudWatch.getMetricStatistics(request);
      for (Datapoint point : result.getDatapoints()) {
        totalSizeInBytes += point
            .getSum()
            .longValue();
      }
      return totalSizeInBytes;
    }
  });
}

@Test
public void shouldCountBytesWhenSingleDataPointReturned() throws Exception {
  Instant countSince = new Instant("2017-04-06T10:00:00.000Z");
  Instant countTo = new Instant("2017-04-06T11:00:00.000Z");
  Minutes periodTime = Minutes.minutesBetween(countSince, countTo);
  GetMetricStatisticsRequest metricStatisticsRequest =
      underTest.createMetricStatisticsRequest(STREAM, countSince, countTo, periodTime);
  GetMetricStatisticsResult result = new GetMetricStatisticsResult()
      .withDatapoints(new Datapoint().withSum(1.0));

  given(cloudWatch.getMetricStatistics(metricStatisticsRequest)).willReturn(result);

  long backlogBytes = underTest.getBacklogBytes(STREAM, countSince, countTo);

  assertThat(backlogBytes).isEqualTo(1L);
}

@Test
public void shouldCountBytesWhenMultipleDataPointsReturned() throws Exception {
  Instant countSince = new Instant("2017-04-06T10:00:00.000Z");
  Instant countTo = new Instant("2017-04-06T11:00:00.000Z");
  Minutes periodTime = Minutes.minutesBetween(countSince, countTo);
  GetMetricStatisticsRequest metricStatisticsRequest =
      underTest.createMetricStatisticsRequest(STREAM, countSince, countTo, periodTime);
  GetMetricStatisticsResult result = new GetMetricStatisticsResult()
      .withDatapoints(
          new Datapoint().withSum(1.0),
          new Datapoint().withSum(3.0),
          new Datapoint().withSum(2.0)
      );

  given(cloudWatch.getMetricStatistics(metricStatisticsRequest)).willReturn(result);

  long backlogBytes = underTest.getBacklogBytes(STREAM, countSince, countTo);

  assertThat(backlogBytes).isEqualTo(6L);
}

@Test
public void testMetricPeriod() {
  new CloudWatchCollector(
          "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount\n  period_seconds: 100\n  range_seconds: 200\n  delay_seconds: 300", client).register(registry);

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest) anyObject()))
          .thenReturn(new GetMetricStatisticsResult());

  registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance"}, new String[]{"aws_elb", ""});


  Mockito.verify(client).getMetricStatistics((GetMetricStatisticsRequest) argThat(
          new GetMetricStatisticsRequestMatcher()
                  .Namespace("AWS/ELB")
                  .MetricName("RequestCount")
                  .Period(100)
  ));
}

@Test
public void testDefaultPeriod() {
  new CloudWatchCollector(
                  "---\nregion: reg\nperiod_seconds: 100\nrange_seconds: 200\ndelay_seconds: 300\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount", client).register(registry);

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest) anyObject()))
          .thenReturn(new GetMetricStatisticsResult());

  registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance"}, new String[]{"aws_elb", ""});


  Mockito.verify(client).getMetricStatistics((GetMetricStatisticsRequest) argThat(
          new GetMetricStatisticsRequestMatcher()
                  .Namespace("AWS/ELB")
                  .MetricName("RequestCount")
                  .Period(100)
  ));
}

@Test
public void testAllStatistics() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount", client).register(registry);

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(1.0)
              .withMaximum(2.0).withMinimum(3.0).withSampleCount(4.0).withSum(5.0)));

  assertEquals(1.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_maximum", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
  assertEquals(3.0, registry.getSampleValue("aws_elb_request_count_minimum", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
  assertEquals(4.0, registry.getSampleValue("aws_elb_request_count_sample_count", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
  assertEquals(5.0, registry.getSampleValue("aws_elb_request_count_sum", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
}

@Test
public void testDimensions() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount\n  aws_dimensions:\n  - AvailabilityZone\n  - LoadBalancerName", client).register(registry);

  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimensions("AvailabilityZone", "LoadBalancerName"))))
      .thenReturn(new ListMetricsResult().withMetrics(
        new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myLB")),
        new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myLB"), new Dimension().withName("ThisExtraDimensionIsIgnored").withValue("dummy")),
        new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("b"), new Dimension().withName("LoadBalancerName").withValue("myOtherLB"))));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "a").Dimension("LoadBalancerName", "myLB"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(2.0)));
  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "b").Dimension("LoadBalancerName", "myOtherLB"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(3.0)));

  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "a", "myLB"}), .01);
  assertEquals(3.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "b", "myOtherLB"}), .01);
  assertNull(registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name", "this_extra_dimension_is_ignored"}, new String[]{"aws_elb", "", "a", "myLB", "dummy"}));
}

@Test
public void testDimensionSelect() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount\n  aws_dimensions:\n  - AvailabilityZone\n  - LoadBalancerName\n  aws_dimension_select:\n    LoadBalancerName:\n    - myLB", client).register(registry);
  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimensions("AvailabilityZone", "LoadBalancerName"))))
      .thenReturn(new ListMetricsResult().withMetrics(
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myLB")),
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("b"), new Dimension().withName("LoadBalancerName").withValue("myLB")),
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myOtherLB"))));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "a").Dimension("LoadBalancerName", "myLB"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(2.0)));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "b").Dimension("LoadBalancerName", "myLB"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(2.0)));

  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "a", "myLB"}), .01);
  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "b", "myLB"}), .01);
  assertNull(registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "a", "myOtherLB"}));
}

@Test
public void testDimensionSelectRegex() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount\n  aws_dimensions:\n  - AvailabilityZone\n  - LoadBalancerName\n  aws_dimension_select_regex:\n    LoadBalancerName:\n    - myLB(.*)", client).register(registry);

  Mockito.when(client.listMetrics((ListMetricsRequest) argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimensions("AvailabilityZone", "LoadBalancerName"))))
      .thenReturn(new ListMetricsResult().withMetrics(
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myLB1")),
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("b"), new Dimension().withName("LoadBalancerName").withValue("myLB2")),
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myOtherLB"))));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest) argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "a").Dimension("LoadBalancerName", "myLB1"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(2.0)));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest) argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "b").Dimension("LoadBalancerName", "myLB2"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(2.0)));

  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "a", "myLB1"}), .01);
  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "b", "myLB2"}), .01);
  assertNull(registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "a", "myOtherLB"}));
}

@Test
public void testGetDimensionsUsesNextToken() throws Exception {
  new CloudWatchCollector(
          "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount\n  aws_dimensions:\n  - AvailabilityZone\n  - LoadBalancerName\n  aws_dimension_select:\n    LoadBalancerName:\n    - myLB", client).register(registry);

  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimensions("AvailabilityZone", "LoadBalancerName"))))
      .thenReturn(new ListMetricsResult().withNextToken("ABC"));
  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimensions("AvailabilityZone", "LoadBalancerName").NextToken("ABC"))))
      .thenReturn(new ListMetricsResult().withMetrics(
          new Metric().withDimensions(new Dimension().withName("AvailabilityZone").withValue("a"), new Dimension().withName("LoadBalancerName").withValue("myLB"))));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount").Dimension("AvailabilityZone", "a").Dimension("LoadBalancerName", "myLB"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withAverage(2.0)));

  assertEquals(2.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance", "availability_zone", "load_balancer_name"}, new String[]{"aws_elb", "", "a", "myLB"}), .01);
}

@Test
public void testExtendedStatistics() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: Latency\n  aws_extended_statistics:\n  - p95\n  - p99.99", client).register(registry);

  HashMap<String, Double> extendedStatistics = new HashMap<String, Double>();
  extendedStatistics.put("p95", 1.0);
  extendedStatistics.put("p99.99", 2.0);

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("Latency"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withExtendedStatistics(extendedStatistics)));

  assertEquals(1.0, registry.getSampleValue("aws_elb_latency_p95", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
  assertEquals(2.0, registry.getSampleValue("aws_elb_latency_p99_99", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
}

public void monitorCPUUsage() {
    AmazonCloudWatchClient cloudClient = new AmazonCloudWatchClient(
            getAwsCredentials());
    GetMetricStatisticsRequest request = new GetMetricStatisticsRequest();
    Calendar cal = Calendar.getInstance();
    request.setEndTime(cal.getTime());
    cal.add(Calendar.MINUTE, -5);
    request.setStartTime(cal.getTime());
    request.setNamespace("AWS/EC2");
    List<String> statistics = new ArrayList<String>();
    statistics.add("Maximium");
    statistics.add("Average");
    request.setStatistics(statistics);
    request.setMetricName("CPUUtilization");
    request.setPeriod(300);
    Dimension dimension = new Dimension();
    dimension.setName("InstanceId");
    dimension.setValue("i-d93fa2a4");
    List<Dimension> dimensions = new ArrayList<Dimension>();
    dimensions.add(dimension);
    request.setDimensions(dimensions);
    GetMetricStatisticsResult result = cloudClient
            .getMetricStatistics(request);
    List<Datapoint> dataPoints = result.getDatapoints();
    for (Datapoint dataPoint : dataPoints) {
        System.out.println(dataPoint.getAverage());
    }

}

/**
 * GetMetricStaticticsTest to get the data points
 *
 * @return Datapoint
 */
protected final Datapoint getMetricStaticticsTest(String metricName) {
    Datapoint dataPoint = null;
    GetMetricStatisticsRequest request = new GetMetricStatisticsRequest();
    request.setStartTime(new DateTime().plusHours(HOURS).toDate());
    request.withNamespace(NAMESPACE);
    request.withPeriod(60 * 60);
    request.withMetricName(metricName);
    request.withStatistics("Average", "SampleCount");
    request.withEndTime(new Date());
    GetMetricStatisticsResult result = amazonCloudWatchClient.getMetricStatistics(request);
    if (result != null && !result.getDatapoints().isEmpty()) {
        dataPoint = result.getDatapoints().get(0);
    }

    return dataPoint;
}

public GetMetricStatisticsResult getCpuUtilization(String name) {
    Dimension instanceDimension = new Dimension();

    if (namespace.endsWith("EC2")) {
        instanceDimension.setName("InstanceId");
    } else {
        instanceDimension.setName("DBInstanceIdentifier");
    }
    instanceDimension.setValue(name);

    Calendar startCal = Calendar.getInstance();
    Calendar endCal = Calendar.getInstance();

    startCal.add(Calendar.MINUTE, -10);
    startCal.set(Calendar.SECOND, 0);

    GetMetricStatisticsRequest request = new GetMetricStatisticsRequest()
            .withStartTime(startCal.getTime())
            .withEndTime(endCal.getTime())
            .withNamespace(namespace)
            .withPeriod(60)
            .withMetricName("CPUUtilization")
            .withStatistics("Average")
            .withStatistics("Maximum")
            .withDimensions(Arrays.asList(instanceDimension));

    GetMetricStatisticsResult result = sort(cloudWatch.getMetricStatistics(request).getDatapoints());

    if (logger.isDebugEnabled()) {
        if (result.getDatapoints() != null && result.getDatapoints().size() > 0) {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            logger.debug("[{}:{}] {}, {} ~ {}", new Object[] {namespace, pulse.getId(), result, sdf.format(startCal.getTime()), sdf.format(endCal.getTime())});
        }
    }

    return result;
}

public GetMetricStatisticsResult getRequestCount(String name) {
    Dimension instanceDimension = new Dimension();

    String ns = null;
    if (pulse.getType().equals("application")) {
            ns = "AWS/ApplicationELB";
        instanceDimension.setName("LoadBalancer");
    } else {
            ns = "AWS/ELB";
        instanceDimension.setName("LoadBalancerName");
    }

    instanceDimension.setValue(name);

    Calendar startCal = Calendar.getInstance();
    Calendar endCal = Calendar.getInstance();

    startCal.add(Calendar.MINUTE, -10);
    startCal.set(Calendar.SECOND, 0);

    GetMetricStatisticsRequest request = new GetMetricStatisticsRequest()
            .withStartTime(startCal.getTime())
            .withEndTime(endCal.getTime())
            .withNamespace(ns)
            .withPeriod(60)
            .withMetricName("RequestCount")
            .withStatistics("Sum")
            .withDimensions(Arrays.asList(instanceDimension));

    GetMetricStatisticsResult result = sort(cloudWatch.getMetricStatistics(request).getDatapoints());

    if (logger.isDebugEnabled()) {
        if (result.getDatapoints() != null && result.getDatapoints().size() > 0) {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            logger.debug("[{}:{}] {}, {} ~ {}", new Object[] {namespace, pulse.getId(), result, sdf.format(startCal.getTime()), sdf.format(endCal.getTime())});
        }
    }

    return result;
}

private GetMetricStatisticsResult sort(List<Datapoint> resultSet) {
    Collections.sort(resultSet, new Comparator<Datapoint>() {
        @Override
        public int compare(Datapoint o1, Datapoint o2) {
            return o1.getTimestamp().compareTo(o2.getTimestamp());
        }
    });

    return new GetMetricStatisticsResult().withDatapoints(resultSet);
}

@Override
public void onSuccess(GetMetricStatisticsRequest request,
        GetMetricStatisticsResult result) {
    try {
        OperationContext.restoreOperationContext(this.opContext);
        List<ServiceStat> statDatapoints = new ArrayList<>();
        List<Datapoint> dpList = result.getDatapoints();
        if (dpList != null && dpList.size() != 0) {
            for (Datapoint dp : dpList) {
                ServiceStat stat = new ServiceStat();
                stat.latestValue = dp.getAverage();
                stat.unit = AWSStatsNormalizer.getNormalizedUnitValue(dp.getUnit());
                stat.sourceTimeMicrosUtc = TimeUnit.MILLISECONDS
                        .toMicros(dp.getTimestamp().getTime());
                statDatapoints.add(stat);
            }

            this.statsData.statsResponse.statValues
                    .put(AWSStatsNormalizer.getNormalizedStatKeyValue(result.getLabel()),
                            statDatapoints);
        }

        if (this.statsData.numResponses.incrementAndGet() == this.numOfMetrics) {
            sendStats(this.statsData);
        }
    } catch (Exception e) {
        this.statsData.taskManager.patchTaskToFailure(e);
    }
}

public void lookupAndSaveMetricData( CloudWatchMetric metric, String dimensionValue, String type ) throws CandlestackAWSException, CandlestackException {

        String datapointDateMapKey = getDatapointDateMapKey( metric, dimensionValue );

        // Determine the last time we fetched datapoints for this metric and dimension
        Date lastDatapointDate = lastDatapointDateMap.get( datapointDateMapKey );
        if ( lastDatapointDate == null ) {
            lastDatapointDate = metricsReaderWriter.readMostRecentMetricDate( type, dimensionValue, metric.getName() );
        }

        // Build the request and execute it
        GetMetricStatisticsRequest request = cloudWatchRequest( metric, dimensionValue, lastDatapointDate );
        GetMetricStatisticsResult result = cloudWatchClient.getMetricStatistics( request );

        // Sort the datapoints in chronological order
        List<Datapoint> datapoints = result.getDatapoints();
        datapoints.sort( new DatapointComparator() );

        // Write the data points
        for ( Datapoint datapoint : datapoints ) {

            // Only care about data points that have happened after the last one
            if ( lastDatapointDate == null || datapoint.getTimestamp().after( lastDatapointDate ) ) {
                lastDatapointDate = datapoint.getTimestamp();
                metricsReaderWriter.writeMetric( type, dimensionValue, datapoint.getTimestamp(), metric.getName(), metric.getStatistic().getValueFromDatapoint( datapoint ) );
            }

        }

        // Update the date map
        lastDatapointDateMap.put( datapointDateMapKey, lastDatapointDate );

    }

public static List<Datum> getMetric(String metricName, Dimension dim, String namespace, Date startTime, int period, Statistic statistic, StandardUnit unit) {
    connect();

    GetMetricStatisticsRequest req = new GetMetricStatisticsRequest();

    req.setMetricName(metricName);

    List<Dimension> dimensions = new ArrayList<Dimension>();
    dimensions.add(dim);
    req.setDimensions(dimensions);

    req.setNamespace(namespace);

    req.setStartTime(startTime);
    req.setEndTime(new Date());

    if (period % 60 != 0)
        period = (period / 60) * 60;
    req.setPeriod(period);

    if (unit != null)
        req.setUnit(unit);

    if (statistic == null)
        statistic = Statistic.Average;
    List<String> statistics = new ArrayList<String>();
    statistics.add(statistic.name());
    req.setStatistics(statistics);

    GetMetricStatisticsResult res = client.getMetricStatistics(req);
    return Datum.getAllData(res.getDatapoints(), metricName, statistic);
}

@Test
public void testUsesNewestDatapoint() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/ELB\n  aws_metric_name: RequestCount", client).register(registry);

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/ELB").MetricName("RequestCount"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date(1)).withAverage(1.0),
          new Datapoint().withTimestamp(new Date(3)).withAverage(3.0),
          new Datapoint().withTimestamp(new Date(2)).withAverage(2.0)));

  assertEquals(3.0, registry.getSampleValue("aws_elb_request_count_average", new String[]{"job", "instance"}, new String[]{"aws_elb", ""}), .01);
}

@Test
public void testDynamoIndexDimensions() throws Exception {
  new CloudWatchCollector(
      "---\nregion: reg\nmetrics:\n- aws_namespace: AWS/DynamoDB\n  aws_metric_name: ConsumedReadCapacityUnits\n  aws_dimensions:\n  - TableName\n  - GlobalSecondaryIndexName\n- aws_namespace: AWS/DynamoDB\n  aws_metric_name: OnlineIndexConsumedWriteCapacity\n  aws_dimensions:\n  - TableName\n  - GlobalSecondaryIndexName\n- aws_namespace: AWS/DynamoDB\n  aws_metric_name: ConsumedReadCapacityUnits\n  aws_dimensions:\n  - TableName", client).register(registry);
  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/DynamoDB").MetricName("ConsumedReadCapacityUnits").Dimensions("TableName", "GlobalSecondaryIndexName"))))
      .thenReturn(new ListMetricsResult().withMetrics(
        new Metric().withDimensions(new Dimension().withName("TableName").withValue("myTable"), new Dimension().withName("GlobalSecondaryIndexName").withValue("myIndex"))));
  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/DynamoDB").MetricName("OnlineIndexConsumedWriteCapacity").Dimensions("TableName", "GlobalSecondaryIndexName"))))
      .thenReturn(new ListMetricsResult().withMetrics(
        new Metric().withDimensions(new Dimension().withName("TableName").withValue("myTable"), new Dimension().withName("GlobalSecondaryIndexName").withValue("myIndex"))));
  Mockito.when(client.listMetrics((ListMetricsRequest)argThat(
      new ListMetricsRequestMatcher().Namespace("AWS/DynamoDB").MetricName("ConsumedReadCapacityUnits").Dimensions("TableName"))))
      .thenReturn(new ListMetricsResult().withMetrics(
        new Metric().withDimensions(new Dimension().withName("TableName").withValue("myTable"))));

  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/DynamoDB").MetricName("ConsumedReadCapacityUnits").Dimension("TableName", "myTable").Dimension("GlobalSecondaryIndexName", "myIndex"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withSum(1.0)));
  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/DynamoDB").MetricName("OnlineIndexConsumedWriteCapacity").Dimension("TableName", "myTable").Dimension("GlobalSecondaryIndexName", "myIndex"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withSum(2.0)));
  Mockito.when(client.getMetricStatistics((GetMetricStatisticsRequest)argThat(
      new GetMetricStatisticsRequestMatcher().Namespace("AWS/DynamoDB").MetricName("ConsumedReadCapacityUnits").Dimension("TableName", "myTable"))))
      .thenReturn(new GetMetricStatisticsResult().withDatapoints(
          new Datapoint().withTimestamp(new Date()).withSum(3.0)));

  assertEquals(1.0, registry.getSampleValue("aws_dynamodb_consumed_read_capacity_units_index_sum", new String[]{"job", "instance", "table_name", "global_secondary_index_name"}, new String[]{"aws_dynamodb", "", "myTable", "myIndex"}), .01);
  assertEquals(2.0, registry.getSampleValue("aws_dynamodb_online_index_consumed_write_capacity_sum", new String[]{"job", "instance", "table_name", "global_secondary_index_name"}, new String[]{"aws_dynamodb", "", "myTable", "myIndex"}), .01);
  assertEquals(3.0, registry.getSampleValue("aws_dynamodb_consumed_read_capacity_units_sum", new String[]{"job", "instance", "table_name"}, new String[]{"aws_dynamodb", "", "myTable"}), .01);
}

public GetMetricStatisticsResult getMemoryUtilization(String name) {
    Dimension instanceDimension = new Dimension();

    String ns = null;
    String metric = null;
    if (namespace.endsWith("EC2")) {
            ns = "System/Linux";
        instanceDimension.setName("InstanceId");
        metric = "MemoryUtilization";
    } else {
            ns = namespace;
        instanceDimension.setName("DBInstanceIdentifier");
        metric = "FreeableMemory";
    }
    instanceDimension.setValue(name);

    Calendar startCal = Calendar.getInstance();
    Calendar endCal = Calendar.getInstance();

    startCal.add(Calendar.MINUTE, -10);
    startCal.set(Calendar.SECOND, 0);

    GetMetricStatisticsRequest request = new GetMetricStatisticsRequest()
            .withStartTime(startCal.getTime())
            .withEndTime(endCal.getTime())
            .withNamespace(ns)
            .withPeriod(60)
            .withMetricName(metric)
            .withStatistics("Average")
            .withStatistics("Maximum")
            .withDimensions(Arrays.asList(instanceDimension));

    GetMetricStatisticsResult result = sort(cloudWatch.getMetricStatistics(request).getDatapoints());

    if (logger.isDebugEnabled()) {
        if (result.getDatapoints() != null && result.getDatapoints().size() > 0) {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            logger.debug("[{}:{}] {}, {} ~ {}", new Object[] {namespace, pulse.getId(), result, sdf.format(startCal.getTime()), sdf.format(endCal.getTime())});
        }
    }

    return result;
}

/**
 * Gets EC2 statistics.
 *
 * @param statsData The context object for stats.
 * @param metricNames The metrics names to gather stats for.
 * @param isAggregateStats Indicates where we are interested in aggregate stats or not.
 */
private void getEC2Stats(AWSStatsDataHolder statsData, String[] metricNames,
        boolean isAggregateStats) {
    if (getAWSAsyncStatsClient(statsData) == null) {
        return;
    }
    Long collectionPeriod = Long.getLong(AWS_COLLECTION_PERIOD_SECONDS, DEFAULT_AWS_COLLECTION_PERIOD_SECONDS);
    for (String metricName : metricNames) {
        GetMetricStatisticsRequest metricRequest = new GetMetricStatisticsRequest();
        // get datapoint for the for the passed in time window.
        try {
            setRequestCollectionWindow(
                    TimeUnit.MINUTES.toMicros(MAX_METRIC_COLLECTION_WINDOW_IN_MINUTES),
                    statsData.statsRequest.lastCollectionTimeMicrosUtc,
                    collectionPeriod,
                    metricRequest);
        } catch (IllegalStateException e) {
            // no data to process. notify parent
            statsData.taskManager.finishTask();
            return;
        }
        metricRequest.setPeriod(collectionPeriod.intValue());
        metricRequest.setStatistics(Arrays.asList(STATISTICS));
        metricRequest.setNamespace(NAMESPACE);

        // Provide instance id dimension only if it is not aggregate stats.
        if (!isAggregateStats) {
            List<Dimension> dimensions = new ArrayList<>();
            Dimension dimension = new Dimension();
            dimension.setName(DIMENSION_INSTANCE_ID);
            String instanceId = statsData.computeDesc.id;
            dimension.setValue(instanceId);
            dimensions.add(dimension);
            metricRequest.setDimensions(dimensions);
        }

        metricRequest.setMetricName(metricName);

        logFine(() -> String.format("Retrieving %s metric from AWS", metricName));
        AsyncHandler<GetMetricStatisticsRequest, GetMetricStatisticsResult> resultHandler = new AWSStatsHandler(
                statsData, metricNames.length, isAggregateStats);
        statsData.statsClient.getMetricStatisticsAsync(metricRequest, resultHandler);
    }
}

private void getBillingStats(AWSStatsDataHolder statsData) {
    if (getAWSAsyncBillingClient(statsData) == null) {
        return;
    }
    Dimension dimension = new Dimension();
    dimension.setName(DIMENSION_CURRENCY);
    dimension.setValue(DIMENSION_CURRENCY_VALUE);
    GetMetricStatisticsRequest request = new GetMetricStatisticsRequest();
    // AWS pushes billing metrics every 4 hours. However the timeseries returned does not have
    // static time stamps associated with the data points. The timestamps range from
    // (currentTime - 4 hrs) and are spaced at 4 hrs.
    // Get all 14 days worth of estimated charges data by default when last collection time is not set.
    // Otherwise set the window to lastCollectionTime - 4 hrs.
    Long lastCollectionTimeForEstimatedCharges = null;
    Long collectionPeriod = Long.getLong(AWS_COLLECTION_PERIOD_SECONDS, DEFAULT_AWS_COLLECTION_PERIOD_SECONDS);
    if (statsData.statsRequest.lastCollectionTimeMicrosUtc != null) {
        lastCollectionTimeForEstimatedCharges =
                statsData.statsRequest.lastCollectionTimeMicrosUtc
                        - TimeUnit.HOURS.toMicros(COST_COLLECTION_PERIOD_IN_HOURS);

    }

    // defaulting to fetch 14 days of estimated charges data
    try {
        setRequestCollectionWindow(
                TimeUnit.DAYS.toMicros(COST_COLLECTION_WINDOW_IN_DAYS),
                lastCollectionTimeForEstimatedCharges,
                collectionPeriod,
                request);
    } catch (IllegalStateException e) {
        // no data to process. notify parent
        statsData.taskManager.finishTask();
        return;
    }

    request.setPeriod(COST_COLLECTION_PERIOD_IN_SECONDS);
    request.setStatistics(Arrays.asList(STATISTICS));
    request.setNamespace(BILLING_NAMESPACE);
    request.setDimensions(Collections.singletonList(dimension));
    request.setMetricName(AWSConstants.ESTIMATED_CHARGES);

    logFine(() -> String.format("Retrieving %s metric from AWS",
            AWSConstants.ESTIMATED_CHARGES));
    AsyncHandler<GetMetricStatisticsRequest, GetMetricStatisticsResult> resultHandler = new AWSBillingStatsHandler(
            statsData, lastCollectionTimeForEstimatedCharges);
    statsData.billingClient.getMetricStatisticsAsync(request, resultHandler);
}

@Override
public void onSuccess(GetMetricStatisticsRequest request,
        GetMetricStatisticsResult result) {
    try {
        OperationContext.restoreOperationContext(this.opContext);
        List<Datapoint> dpList = result.getDatapoints();
        // Sort the data points in increasing order of timestamp to calculate Burn rate
        Collections
                .sort(dpList, (o1, o2) -> o1.getTimestamp().compareTo(o2.getTimestamp()));

        List<ServiceStat> estimatedChargesDatapoints = new ArrayList<>();
        if (dpList != null && dpList.size() != 0) {
            for (Datapoint dp : dpList) {
                // If the datapoint collected is older than the last collection time, skip it.
                if (this.lastCollectionTimeMicrosUtc != null &&
                        TimeUnit.MILLISECONDS.toMicros(dp.getTimestamp()
                                .getTime())
                                <= this.lastCollectionTimeMicrosUtc) {
                    continue;
                }

                // If there is no lastCollectionTime or the datapoint collected in newer
                // than the lastCollectionTime, push it.
                ServiceStat stat = new ServiceStat();
                stat.latestValue = dp.getAverage();
                stat.unit = AWSStatsNormalizer
                        .getNormalizedUnitValue(DIMENSION_CURRENCY_VALUE);
                stat.sourceTimeMicrosUtc = TimeUnit.MILLISECONDS
                        .toMicros(dp.getTimestamp().getTime());
                estimatedChargesDatapoints.add(stat);
            }

            this.statsData.statsResponse.statValues.put(
                    AWSStatsNormalizer.getNormalizedStatKeyValue(result.getLabel()),
                    estimatedChargesDatapoints);

            // Calculate average burn rate only if there is more than 1 datapoint available.
            // This will ensure that NaN errors will not occur.
            if (dpList.size() > 1) {
                ServiceStat averageBurnRate = new ServiceStat();
                averageBurnRate.latestValue = AWSUtils.calculateAverageBurnRate(dpList);
                averageBurnRate.unit = AWSStatsNormalizer
                        .getNormalizedUnitValue(DIMENSION_CURRENCY_VALUE);
                averageBurnRate.sourceTimeMicrosUtc = Utils.getSystemNowMicrosUtc();
                this.statsData.statsResponse.statValues.put(
                        AWSStatsNormalizer
                                .getNormalizedStatKeyValue(AWSConstants.AVERAGE_BURN_RATE),
                        Collections.singletonList(averageBurnRate));
            }

            // Calculate current burn rate only if there is more than 1 day worth of data available.
            if (dpList.size() > NUM_OF_COST_DATAPOINTS_IN_A_DAY) {
                ServiceStat currentBurnRate = new ServiceStat();
                currentBurnRate.latestValue = AWSUtils.calculateCurrentBurnRate(dpList);
                currentBurnRate.unit = AWSStatsNormalizer
                        .getNormalizedUnitValue(DIMENSION_CURRENCY_VALUE);
                currentBurnRate.sourceTimeMicrosUtc = Utils.getSystemNowMicrosUtc();
                this.statsData.statsResponse.statValues.put(
                        AWSStatsNormalizer
                                .getNormalizedStatKeyValue(AWSConstants.CURRENT_BURN_RATE),
                        Collections.singletonList(currentBurnRate));
            }
        }
        sendStats(this.statsData);
    } catch (Exception e) {
        this.statsData.taskManager.patchTaskToFailure(e);
    }
}

/**
 * Retrieves the total number of requests that were made to the load
 * balancer during the given time interval in the past
 *
 * @param loadBalancerName
 * @param region
 * @param timeInterval     in seconds which must be multiple of 60
 * @return number of requests made
 */
public int getRequestCount(String loadBalancerName, String region,
                           int timeInterval) {
    int count = 0;

    try {
        GetMetricStatisticsRequest request = new GetMetricStatisticsRequest();
        request.setMetricName(Constants.REQUEST_COUNT_METRIC_NAME);
        request.setNamespace(Constants.CLOUD_WATCH_NAMESPACE_NAME);

        Date currentTime = new DateTime(DateTimeZone.UTC).toDate();
        Date pastTime = new DateTime(DateTimeZone.UTC).minusSeconds(
                timeInterval).toDate();

        request.setStartTime(pastTime);
        request.setEndTime(currentTime);

        request.setPeriod(timeInterval);

        HashSet<String> statistics = new HashSet<String>();
        statistics.add(Constants.SUM_STATISTICS_NAME);
        request.setStatistics(statistics);

        HashSet<Dimension> dimensions = new HashSet<Dimension>();
        Dimension loadBalancerDimension = new Dimension();
        loadBalancerDimension
                .setName(Constants.LOAD_BALANCER_DIMENTION_NAME);
        loadBalancerDimension.setValue(loadBalancerName);
        dimensions.add(loadBalancerDimension);
        request.setDimensions(dimensions);

        cloudWatchClient.setEndpoint(String.format(
                Constants.CLOUD_WATCH_ENDPOINT_URL_FORMAT, region));

        GetMetricStatisticsResult result = cloudWatchClient
                .getMetricStatistics(request);

        List<Datapoint> dataPoints = result.getDatapoints();

        if (dataPoints != null && dataPoints.size() > 0) {
            count = dataPoints.get(0).getSum().intValue();
        }

    } catch (AmazonClientException e) {
        log.error(
                "Could not get request count statistics of load balancer "
                        + loadBalancerName, e);
    }

    return count;
}

/**
 * Retrieves the number of responses generated for a particular response
 * code like 2XX, 3XX, 4XX, 5XX
 *
 * @param loadBalancerName
 * @param region
 * @param metricName       which is one among HTTPCode_Backend_2XX or
 *                         HTTPCode_Backend_3XX or HTTPCode_Backend_4XX or
 *                         HTTPCode_Backend_5XX
 * @param startTime        of the window to be scanned
 * @param endTime          of the window to be scanned
 * @param timeInterval     in seconds
 * @return number for response for this metric
 */
public int getResponseCountForMetric(String loadBalancerName,
                                     String region, String metricName, Date startTime, Date endTime,
                                     int timeInterval) {
    int count = 0;

    try {
        GetMetricStatisticsRequest request = new GetMetricStatisticsRequest();
        request.setMetricName(metricName);
        request.setNamespace(Constants.CLOUD_WATCH_NAMESPACE_NAME);

        request.setStartTime(startTime);
        request.setEndTime(endTime);

        request.setPeriod(timeInterval);

        HashSet<String> statistics = new HashSet<String>();
        statistics.add(Constants.SUM_STATISTICS_NAME);
        request.setStatistics(statistics);

        HashSet<Dimension> dimensions = new HashSet<Dimension>();
        Dimension loadBalancerDimension = new Dimension();
        loadBalancerDimension
                .setName(Constants.LOAD_BALANCER_DIMENTION_NAME);
        loadBalancerDimension.setValue(loadBalancerName);
        dimensions.add(loadBalancerDimension);
        request.setDimensions(dimensions);

        cloudWatchClient.setEndpoint(String.format(
                Constants.CLOUD_WATCH_ENDPOINT_URL_FORMAT, region));

        GetMetricStatisticsResult result = cloudWatchClient
                .getMetricStatistics(request);

        List<Datapoint> dataPoints = result.getDatapoints();

        if (dataPoints != null && dataPoints.size() > 0) {
            count = dataPoints.get(0).getSum().intValue();
        }

    } catch (AmazonClientException e) {
        log.error("Could not get the statistics for metric " + metricName
                + " of load balancer " + loadBalancerName, e);
    }

    return count;
}