/**
* Copyright 2013 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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.netflix.servo.publish.cloudwatch;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSCredentialsProvider;
import com.amazonaws.services.cloudwatch.AmazonCloudWatch;
import com.amazonaws.services.cloudwatch.AmazonCloudWatchClient;
import com.amazonaws.services.cloudwatch.model.Dimension;
import com.amazonaws.services.cloudwatch.model.MetricDatum;
import com.amazonaws.services.cloudwatch.model.PutMetricDataRequest;
import com.google.common.base.Preconditions;
import com.netflix.servo.Metric;
import com.netflix.servo.aws.AwsServiceClients;
import com.netflix.servo.publish.BaseMetricObserver;
import com.netflix.servo.tag.Tag;
import com.netflix.servo.tag.TagList;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
/**
* Writes observations to Amazon's CloudWatch.
*/
public class CloudWatchMetricObserver extends BaseMetricObserver {
private static final Logger LOG = LoggerFactory.getLogger(CloudWatchMetricObserver.class);
/**
* Experimentally derived value for the largest exponent that can be sent to cloudwatch
* without triggering an InvalidParameterValue exception. See CloudWatchValueTest for the test
* program that was used.
*/
private static final int MAX_EXPONENT = 360;
/**
* Experimentally derived value for the smallest exponent that can be sent to cloudwatch
* without triggering an InvalidParameterValue exception. See CloudWatchValueTest for the test
* program that was used.
*/
private static final int MIN_EXPONENT = -360;
/**
* Maximum value that can be represented in cloudwatch.
*/
static final double MAX_VALUE = java.lang.Math.pow(2.0, MAX_EXPONENT);
private int batchSize;
private boolean truncateEnabled = false;
private final AmazonCloudWatch cloudWatch;
private final String cloudWatchNamespace;
/**
* @param name Unique name of the observer.
* @param namespace Namespace to use in CloudWatch.
* @param credentials Amazon credentials.
* @deprecated use equivalent constructor that accepts an AWSCredentialsProvider.
*/
@Deprecated
public CloudWatchMetricObserver(String name, String namespace, AWSCredentials credentials) {
this(name, namespace, new AmazonCloudWatchClient(credentials));
}
/**
* @param name Unique name of the observer.
* @param namespace Namespace to use in CloudWatch.
* @param credentials Amazon credentials.
* @param batchSize Batch size to send to Amazon. They currently enforce a max of 20.
* @deprecated use equivalent constructor that accepts an AWSCredentialsProvider.
*/
@Deprecated
public CloudWatchMetricObserver(String name, String namespace, AWSCredentials credentials,
int batchSize) {
this(name, namespace, credentials);
this.batchSize = batchSize;
}
/**
* @param name Unique name of the observer.
* @param namespace Namespace to use in CloudWatch.
* @param provider Amazon credentials provider
*/
public CloudWatchMetricObserver(String name, String namespace,
AWSCredentialsProvider provider) {
this(name, namespace, AwsServiceClients.cloudWatch(provider));
}
/**
* @param name Unique name of the observer.
* @param namespace Namespace to use in CloudWatch.
* @param provider Amazon credentials provider.
* @param batchSize Batch size to send to Amazon. They currently enforce a max of 20.
*/
public CloudWatchMetricObserver(String name, String namespace,
AWSCredentialsProvider provider, int batchSize) {
this(name, namespace, provider);
this.batchSize = batchSize;
}
/**
* @param name Unique name of the observer.
* @param namespace Namespace to use in CloudWatch.
* @param cloudWatch AWS cloudwatch.
*/
public CloudWatchMetricObserver(String name, String namespace, AmazonCloudWatch cloudWatch) {
super(name);
this.cloudWatch = cloudWatch;
this.cloudWatchNamespace = namespace;
batchSize = 20;
}
/**
* @param name Unique name of the observer.
* @param namespace Namespace to use in CloudWatch.
* @param cloudWatch AWS cloudwatch.
* @param batchSize Batch size to send to Amazon. They currently enforce a max of 20.
*/
public CloudWatchMetricObserver(String name, String namespace, AmazonCloudWatch cloudWatch,
int batchSize) {
this(name, namespace, cloudWatch);
this.batchSize = batchSize;
}
/**
* @param metrics The list of metrics you want to send to CloudWatch
*/
public void updateImpl(List<Metric> metrics) {
Preconditions.checkNotNull(metrics);
List<Metric> batch = new ArrayList<Metric>(batchSize);
int batchCount = 1;
while (metrics.size() > 0) {
Metric m = metrics.remove(0);
if (m.hasNumberValue()) {
batch.add(m);
if (batchCount++ % batchSize == 0) {
putMetricData(batch);
batch.clear();
}
}
}
if (!batch.isEmpty()) {
putMetricData(batch);
}
}
private void putMetricData(List<Metric> batch) {
try {
cloudWatch.putMetricData(createPutRequest(batch));
} catch (Exception e) {
LOG.error("Error while submitting data for metrics : " + batch, e);
}
}
PutMetricDataRequest createPutRequest(List<Metric> batch) {
List<MetricDatum> datumList = new ArrayList<MetricDatum>(batch.size());
for (Metric m : batch) {
datumList.add(createMetricDatum(m));
}
return new PutMetricDataRequest().withNamespace(cloudWatchNamespace)
.withMetricData(datumList);
}
MetricDatum createMetricDatum(Metric metric) {
MetricDatum metricDatum = new MetricDatum();
return metricDatum.withMetricName(metric.getConfig().getName())
.withDimensions(createDimensions(metric.getConfig().getTags()))
.withUnit("None")//DataSourceTypeToAwsUnit.getUnit(metric.))
.withTimestamp(new Date(metric.getTimestamp()))
.withValue(truncate(metric.getNumberValue()));
//TODO Need to convert into reasonable units based on DataType
}
/**
* Adjust a double value so it can be successfully written to cloudwatch. This involves capping
* values with large exponents to an experimentally determined max value and converting values
* with large negative exponents to 0. In addition, NaN values will be converted to 0.
*/
Double truncate(Number numberValue) {
// http://docs.amazonwebservices.com/AmazonCloudWatch/latest/APIReference/API_MetricDatum.html
double doubleValue = numberValue.doubleValue();
if (truncateEnabled) {
final int exponent = Math.getExponent(doubleValue);
if (Double.isNaN(doubleValue)) {
doubleValue = 0.0;
} else if (exponent >= MAX_EXPONENT) {
doubleValue = (doubleValue < 0.0) ? -MAX_VALUE : MAX_VALUE;
} else if (exponent <= MIN_EXPONENT) {
doubleValue = 0.0;
}
}
return Double.valueOf(doubleValue);
}
List<Dimension> createDimensions(TagList tags) {
List<Dimension> dimensionList = new ArrayList<Dimension>(tags.size());
for (Tag tag : tags) {
dimensionList.add(new Dimension().withName(tag.getKey()).withValue(tag.getValue()));
}
return dimensionList;
}
public CloudWatchMetricObserver withTruncateEnabled(boolean truncateEnabled) {
this.truncateEnabled = truncateEnabled;
return this;
}
}