/*
* 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 java.util.Set;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.annotation.ThreadSafe;
import com.amazonaws.metrics.AwsSdkMetrics;
import com.amazonaws.metrics.ByteThroughputProvider;
import com.amazonaws.metrics.MetricType;
import com.amazonaws.metrics.RequestMetricCollector;
import com.amazonaws.metrics.ServiceLatencyProvider;
import com.amazonaws.metrics.ServiceMetricCollector;
import com.amazonaws.metrics.ServiceMetricType;
import com.amazonaws.metrics.ThroughputMetricType;
import com.amazonaws.metrics.internal.cloudwatch.spi.Dimensions;
import com.amazonaws.services.cloudwatch.model.Dimension;
import com.amazonaws.services.cloudwatch.model.MetricDatum;
import com.amazonaws.services.cloudwatch.model.StandardUnit;
/**
* This is the default implementation of an AWS SDK service metric collection
* system.
*
* @see RequestMetricCollector
*/
@ThreadSafe
public class ServiceMetricCollectorSupport extends ServiceMetricCollector
{
static final double NANO_PER_SEC = TimeUnit.SECONDS.toNanos(1);
protected final static Log log = LogFactory.getLog(ServiceMetricCollectorSupport.class);
private final BlockingQueue<MetricDatum> queue;
protected ServiceMetricCollectorSupport(BlockingQueue<MetricDatum> queue) {
this.queue = queue;
}
@Override
public void collectByteThroughput(ByteThroughputProvider provider) {
try {
collectByteThroughput0(provider);
} catch(Exception ex) { // defensive code
if (log.isDebugEnabled()) {
log.debug("Ignoring unexpected failure", ex);
}
}
}
/**
* Returns the number of bytes per second, given the byte count and
* duration in nano seconds. Duration of zero nanosecond will be treated
* as 1 nanosecond.
*/
double bytesPerSecond(double byteCount, double durationNano) {
if (byteCount < 0 || durationNano < 0)
throw new IllegalArgumentException();
if (durationNano == 0) {
durationNano = 1.0; // defend against division by zero
if (log.isDebugEnabled()) {
log.debug("Set zero to one to avoid division by zero; but should never get here!");
}
}
double bytesPerSec = (byteCount / durationNano) * NANO_PER_SEC;
if (bytesPerSec == 0) {
if (log.isDebugEnabled()) {
log.debug("zero bytes per sec. Really ?");
}
}
return bytesPerSec;
}
private void collectByteThroughput0(ByteThroughputProvider provider) {
final ThroughputMetricType throughputType = provider.getThroughputMetricType();
final ServiceMetricType byteCountType = throughputType.getByteCountMetricType();
final Set<MetricType> metrics = AwsSdkMetrics.getPredefinedMetrics();
final double byteCount = provider.getByteCount();
double durationNano = provider.getDurationNano();
double bytesPerSec = bytesPerSecond(byteCount, durationNano);
if (metrics.contains(throughputType)) {
// Throughput metric
final Dimension throughputDimension = new Dimension()
.withName(Dimensions.MetricType.name())
.withValue(throughputType.name());
final MetricDatum throughputDatum = new MetricDatum()
.withMetricName(throughputType.getServiceName())
.withDimensions(throughputDimension)
.withUnit(StandardUnit.BytesSecond)
.withValue(bytesPerSec);
safeAddMetricsToQueue(throughputDatum);
}
if (metrics.contains(byteCountType)) {
// Byte count metric
final Dimension byteCountDimension = new Dimension()
.withName(Dimensions.MetricType.name())
.withValue(byteCountType.name());
final MetricDatum byteCountDatum = new MetricDatum()
.withMetricName(byteCountType.getServiceName())
.withDimensions(byteCountDimension)
.withUnit(StandardUnit.Bytes)
.withValue(byteCount);
safeAddMetricsToQueue(byteCountDatum);
}
}
@Override
public void collectLatency(ServiceLatencyProvider provider) {
final ServiceMetricType type = provider.getServiceMetricType();
final Set<MetricType> metrics = AwsSdkMetrics.getPredefinedMetrics();
if (metrics.contains(type)) {
final Dimension dim = new Dimension()
.withName(Dimensions.MetricType.name())
.withValue(type.name());
final MetricDatum datum = new MetricDatum()
.withMetricName(type.getServiceName())
.withDimensions(dim)
.withUnit(StandardUnit.Milliseconds)
.withValue(provider.getDurationMilli());
safeAddMetricsToQueue(datum);
}
}
private void safeAddMetricsToQueue(MetricDatum metric) {
try {
if (!addMetricsToQueue(metric)) {
if (log.isDebugEnabled()) {
log.debug("Failed to add to the metrics queue (due to no space available) for "
+ metric.getMetricName());
}
}
} catch (RuntimeException ex) {
log.warn("Failed to add to the metrics queue for metric: " + metric,
ex);
}
}
/**
* Adds the given metric to the queue, returning true if successful or false
* if no space available.
*/
protected boolean addMetricsToQueue(MetricDatum metric) {
return queue.offer(metric);
}
}