/*
* Copyright 2010-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package com.amazonaws.metrics.internal.cloudwatch;
import static com.amazonaws.metrics.internal.cloudwatch.CloudWatchMetricConfig.NAMESPACE_DELIMITER;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import com.amazonaws.metrics.AwsSdkMetrics;
import com.amazonaws.metrics.RequestMetricCollector;
import com.amazonaws.services.cloudwatch.model.Dimension;
import com.amazonaws.services.cloudwatch.model.MetricDatum;
import com.amazonaws.services.cloudwatch.model.PutMetricDataRequest;
import com.amazonaws.services.cloudwatch.model.StatisticSet;
import com.amazonaws.util.AwsHostNameUtils;
import com.amazonaws.util.json.Jackson;
/**
* An internal builder used to retrieve the next batch of requests to be sent to
* Amazon CloudWatch. Calling method {@link #nextUploadUnits()} blocks as
* necessary.
*/
class BlockingRequestBuilder {
private static final String OS_METRIC_NAME = MachineMetric.getOSMetricName();
private final MachineMetricFactory machineMetricFactory = new MachineMetricFactory();
private final BlockingQueue<MetricDatum> queue;
private final long timeoutNano;
BlockingRequestBuilder(CloudWatchMetricConfig config, BlockingQueue<MetricDatum> queue) {
this.queue = queue;
this.timeoutNano = TimeUnit.MILLISECONDS.toNanos(config.getQueuePollTimeoutMilli());
}
/**
* Returns the next batch of {@link PutMetricDataRequest} to be sent to
* Amazon CloudWatch, blocking as necessary to gather and accumulate the
* necessary statistics. If there is no metrics data, this call blocks
* indefinitely. If there is metrics data, this call will block up to about
* {@link CloudWatchMetricConfig#getQueuePollTimeoutMilli()} number of
* milliseconds.
*/
Iterable<PutMetricDataRequest> nextUploadUnits() throws InterruptedException {
final Map<String,MetricDatum> uniqueMetrics = new HashMap<String,MetricDatum>();
long startNano = System.nanoTime();
while(true) {
final long elapsedNano = System.nanoTime() - startNano;
if (elapsedNano >= timeoutNano) {
return toPutMetricDataRequests(uniqueMetrics);
}
MetricDatum datum = queue.poll(timeoutNano - elapsedNano, TimeUnit.NANOSECONDS);
if (datum == null) {
// timed out
if (uniqueMetrics.size() > 0) {
// return whatever we have so far
return toPutMetricDataRequests(uniqueMetrics);
}
// zero AWS related metrics
if (AwsSdkMetrics.isMachineMetricExcluded()) {
// Short note: nothing to do, so just wait indefinitely.
// (Long note: There exists a pedagogical case where the
// next statement is executed followed by no subsequent AWS
// traffic whatsoever, and then the machine metric is enabled
// via JMX.
// In such case, we require the metric generation to be
// disabled and then re-enabled (eg via JMX).
// So why not always wake up periodically instead of going
// into long wait ?
// I (hchar@) think we should optimize for the most typical
// cases instead of the edge cases. Going into long wait has
// the benefit of relatively less runtime footprint.)
datum = queue.take();
startNano = System.nanoTime();
}
}
// Note at this point datum is null if and only if there is no
// pending AWS related metrics but machine metrics is enabled
if (datum != null)
summarize(datum, uniqueMetrics);
}
}
/**
* Summarizes the given datum into the statistics of the respective unique metric.
*/
private void summarize(MetricDatum datum, Map<String, MetricDatum> uniqueMetrics) {
Double value = datum.getValue();
if (value == null) {
return;
}
List<Dimension> dims = datum.getDimensions();
Collections.sort(dims, DimensionComparator.INSTANCE);
String metricName = datum.getMetricName();
String key = metricName + Jackson.toJsonString(dims);
MetricDatum statDatum = uniqueMetrics.get(key);
if (statDatum == null) {
statDatum = new MetricDatum()
.withDimensions(datum.getDimensions())
.withMetricName(metricName)
.withUnit(datum.getUnit())
.withStatisticValues(new StatisticSet()
.withMaximum(value)
.withMinimum(value)
.withSampleCount(0.0)
.withSum(0.0))
;
uniqueMetrics.put(key, statDatum);
}
StatisticSet stat = statDatum.getStatisticValues();
stat.setSampleCount(stat.getSampleCount() + 1.0);
stat.setSum(stat.getSum() + value);
if (value > stat.getMaximum()) {
stat.setMaximum(value);
} else if (value < stat.getMinimum()) {
stat.setMinimum(value);
}
}
/**
* Consolidates the input metrics into a list of PutMetricDataRequest, each
* within the maximum size limit imposed by CloudWatch.
*/
private Iterable<PutMetricDataRequest> toPutMetricDataRequests(Map<String, MetricDatum> uniqueMetrics) {
// Opportunistically generates some machine metrics whenever there
// is metrics consolidation
for (MetricDatum datum: machineMetricFactory.generateMetrics()) {
summarize(datum, uniqueMetrics);
}
List<PutMetricDataRequest> list = new ArrayList<PutMetricDataRequest>();
List<MetricDatum> data = new ArrayList<MetricDatum>();
for (MetricDatum m: uniqueMetrics.values()) {
data.add(m);
if (data.size() == CloudWatchMetricConfig.MAX_METRICS_DATUM_SIZE) {
list.addAll(newPutMetricDataRequests(data));
data.clear();
}
}
if (data.size() > 0) {
list.addAll(newPutMetricDataRequests(data));
}
return list;
}
private List<PutMetricDataRequest> newPutMetricDataRequests(Collection<MetricDatum> data) {
List<PutMetricDataRequest> list = new ArrayList<PutMetricDataRequest>();
final String ns = AwsSdkMetrics.getMetricNameSpace();
PutMetricDataRequest req = newPutMetricDataRequest(data, ns);
list.add(req);
String perHostNameSpace = null;
final boolean perHost = AwsSdkMetrics.isPerHostMetricEnabled();
if (perHost) {
String hostName = AwsSdkMetrics.getHostMetricName();
hostName = hostName == null ? "" : hostName.trim();
if (hostName.length() == 0)
hostName = AwsHostNameUtils.localHostName();
perHostNameSpace = ns + NAMESPACE_DELIMITER + hostName;
req = newPutMetricDataRequest(data, perHostNameSpace);
list.add(req);
}
String jvmMetricName = AwsSdkMetrics.getJvmMetricName();
if (jvmMetricName != null) {
jvmMetricName = jvmMetricName.trim();
if (jvmMetricName.length() > 0) {
String perJvmNameSpace = perHostNameSpace == null
? ns + NAMESPACE_DELIMITER + jvmMetricName
: perHostNameSpace + NAMESPACE_DELIMITER + jvmMetricName
;
// If OS metrics are already included at the per host level,
// there is little reason, if any, to include them at the
// JVM level. Hence the filtering.
req = newPutMetricDataRequest
(perHost ? filterOSMetrics(data) : data, perJvmNameSpace);
list.add(req);
}
}
return list;
}
/**
* Return a collection of metrics almost the same as the input except with
* all OS metrics removed.
*/
private Collection<MetricDatum> filterOSMetrics(Collection<MetricDatum> data) {
Collection<MetricDatum> output = new ArrayList<MetricDatum>(data.size());
for (MetricDatum datum: data) {
if (!OS_METRIC_NAME.equals(datum.getMetricName()))
output.add(datum);
}
return output;
}
private PutMetricDataRequest newPutMetricDataRequest(
Collection<MetricDatum> data, String namespace) {
return new PutMetricDataRequest()
.withNamespace(namespace)
.withMetricData(data)
.withRequestMetricCollector(RequestMetricCollector.NONE)
;
}
}