package io.prometheus.client.dropwizard;
import com.codahale.metrics.*;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.SortedMap;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Collect Dropwizard metrics from a MetricRegistry.
*/
public class DropwizardExports extends io.prometheus.client.Collector implements io.prometheus.client.Collector.Describable {
private MetricRegistry registry;
private static final Logger LOGGER = Logger.getLogger(DropwizardExports.class.getName());
/**
* @param registry a metric registry to export in prometheus.
*/
public DropwizardExports(MetricRegistry registry) {
this.registry = registry;
}
/**
* Export counter as Prometheus <a href="https://prometheus.io/docs/concepts/metric_types/#gauge">Gauge</a>.
*/
List<MetricFamilySamples> fromCounter(String dropwizardName, Counter counter) {
String name = sanitizeMetricName(dropwizardName);
MetricFamilySamples.Sample sample = new MetricFamilySamples.Sample(name, new ArrayList<String>(), new ArrayList<String>(),
new Long(counter.getCount()).doubleValue());
return Arrays.asList(new MetricFamilySamples(name, Type.GAUGE, getHelpMessage(dropwizardName, counter), Arrays.asList(sample)));
}
private static String getHelpMessage(String metricName, Metric metric){
return String.format("Generated from Dropwizard metric import (metric=%s, type=%s)",
metricName, metric.getClass().getName());
}
/**
* Export gauge as a prometheus gauge.
*/
List<MetricFamilySamples> fromGauge(String dropwizardName, Gauge gauge) {
String name = sanitizeMetricName(dropwizardName);
Object obj = gauge.getValue();
double value;
if (obj instanceof Number) {
value = ((Number) obj).doubleValue();
} else if (obj instanceof Boolean) {
value = ((Boolean) obj) ? 1 : 0;
} else {
LOGGER.log(Level.FINE, String.format("Invalid type for Gauge %s: %s", name,
obj.getClass().getName()));
return new ArrayList<MetricFamilySamples>();
}
MetricFamilySamples.Sample sample = new MetricFamilySamples.Sample(name,
new ArrayList<String>(), new ArrayList<String>(), value);
return Arrays.asList(new MetricFamilySamples(name, Type.GAUGE, getHelpMessage(dropwizardName, gauge), Arrays.asList(sample)));
}
/**
* Export a histogram snapshot as a prometheus SUMMARY.
*
* @param dropwizardName metric name.
* @param snapshot the histogram snapshot.
* @param count the total sample count for this snapshot.
* @param factor a factor to apply to histogram values.
*
*/
List<MetricFamilySamples> fromSnapshotAndCount(String dropwizardName, Snapshot snapshot, long count, double factor, String helpMessage) {
String name = sanitizeMetricName(dropwizardName);
List<MetricFamilySamples.Sample> samples = Arrays.asList(
new MetricFamilySamples.Sample(name, Arrays.asList("quantile"), Arrays.asList("0.5"), snapshot.getMedian() * factor),
new MetricFamilySamples.Sample(name, Arrays.asList("quantile"), Arrays.asList("0.75"), snapshot.get75thPercentile() * factor),
new MetricFamilySamples.Sample(name, Arrays.asList("quantile"), Arrays.asList("0.95"), snapshot.get95thPercentile() * factor),
new MetricFamilySamples.Sample(name, Arrays.asList("quantile"), Arrays.asList("0.98"), snapshot.get98thPercentile() * factor),
new MetricFamilySamples.Sample(name, Arrays.asList("quantile"), Arrays.asList("0.99"), snapshot.get99thPercentile() * factor),
new MetricFamilySamples.Sample(name, Arrays.asList("quantile"), Arrays.asList("0.999"), snapshot.get999thPercentile() * factor),
new MetricFamilySamples.Sample(name + "_count", new ArrayList<String>(), new ArrayList<String>(), count)
);
return Arrays.asList(
new MetricFamilySamples(name, Type.SUMMARY, helpMessage, samples)
);
}
/**
* Convert histogram snapshot.
*/
List<MetricFamilySamples> fromHistogram(String dropwizardName, Histogram histogram) {
return fromSnapshotAndCount(dropwizardName, histogram.getSnapshot(), histogram.getCount(), 1.0,
getHelpMessage(dropwizardName, histogram));
}
/**
* Export Dropwizard Timer as a histogram. Use TIME_UNIT as time unit.
*/
List<MetricFamilySamples> fromTimer(String dropwizardName, Timer timer) {
return fromSnapshotAndCount(dropwizardName, timer.getSnapshot(), timer.getCount(),
1.0D / TimeUnit.SECONDS.toNanos(1L), getHelpMessage(dropwizardName, timer));
}
/**
* Export a Meter as as prometheus COUNTER.
*/
List<MetricFamilySamples> fromMeter(String dropwizardName, Meter meter) {
String name = sanitizeMetricName(dropwizardName);
return Arrays.asList(
new MetricFamilySamples(name + "_total", Type.COUNTER, getHelpMessage(dropwizardName, meter),
Arrays.asList(new MetricFamilySamples.Sample(name + "_total",
new ArrayList<String>(),
new ArrayList<String>(),
meter.getCount())))
);
}
/**
* Replace all unsupported chars with '_'.
*
* @param dropwizardName original metric name.
* @return the sanitized metric name.
*/
public static String sanitizeMetricName(String dropwizardName){
return dropwizardName.replaceAll("[^a-zA-Z0-9:_]", "_");
}
@Override
public List<MetricFamilySamples> collect() {
ArrayList<MetricFamilySamples> mfSamples = new ArrayList<MetricFamilySamples>();
for (SortedMap.Entry<String, Gauge> entry : registry.getGauges().entrySet()) {
mfSamples.addAll(fromGauge(entry.getKey(), entry.getValue()));
}
for (SortedMap.Entry<String, Counter> entry : registry.getCounters().entrySet()) {
mfSamples.addAll(fromCounter(entry.getKey(), entry.getValue()));
}
for (SortedMap.Entry<String, Histogram> entry : registry.getHistograms().entrySet()) {
mfSamples.addAll(fromHistogram(entry.getKey(), entry.getValue()));
}
for (SortedMap.Entry<String, Timer> entry : registry.getTimers().entrySet()) {
mfSamples.addAll(fromTimer(entry.getKey(), entry.getValue()));
}
for (SortedMap.Entry<String, Meter> entry : registry.getMeters().entrySet()) {
mfSamples.addAll(fromMeter(entry.getKey(), entry.getValue()));
}
return mfSamples;
}
@Override
public List<MetricFamilySamples> describe() {
return new ArrayList<MetricFamilySamples>();
}
}