io.prometheus.metrics.expositionformats.OpenMetricsTextFormatWriter Maven / Gradle / Ivy
package io.prometheus.metrics.expositionformats;
import io.prometheus.metrics.model.snapshots.ClassicHistogramBuckets;
import io.prometheus.metrics.model.snapshots.CounterSnapshot;
import io.prometheus.metrics.model.snapshots.DataPointSnapshot;
import io.prometheus.metrics.model.snapshots.DistributionDataPointSnapshot;
import io.prometheus.metrics.model.snapshots.Exemplar;
import io.prometheus.metrics.model.snapshots.Exemplars;
import io.prometheus.metrics.model.snapshots.GaugeSnapshot;
import io.prometheus.metrics.model.snapshots.HistogramSnapshot;
import io.prometheus.metrics.model.snapshots.InfoSnapshot;
import io.prometheus.metrics.model.snapshots.Labels;
import io.prometheus.metrics.model.snapshots.MetricMetadata;
import io.prometheus.metrics.model.snapshots.MetricSnapshot;
import io.prometheus.metrics.model.snapshots.MetricSnapshots;
import io.prometheus.metrics.model.snapshots.Quantile;
import io.prometheus.metrics.model.snapshots.StateSetSnapshot;
import io.prometheus.metrics.model.snapshots.SummarySnapshot;
import io.prometheus.metrics.model.snapshots.UnknownSnapshot;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.util.List;
import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeDouble;
import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeEscapedLabelValue;
import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeLabels;
import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeLong;
import static io.prometheus.metrics.expositionformats.TextFormatUtil.writeTimestamp;
/**
* Write the OpenMetrics text format as defined on https://openmetrics.io.
*/
public class OpenMetricsTextFormatWriter implements ExpositionFormatWriter {
public static final String CONTENT_TYPE = "application/openmetrics-text; version=1.0.0; charset=utf-8";
private final boolean createdTimestampsEnabled;
private final boolean exemplarsOnAllMetricTypesEnabled;
/**
* @param createdTimestampsEnabled defines if {@code _created} timestamps should be included in the output or not.
*/
public OpenMetricsTextFormatWriter(boolean createdTimestampsEnabled, boolean exemplarsOnAllMetricTypesEnabled) {
this.createdTimestampsEnabled = createdTimestampsEnabled;
this.exemplarsOnAllMetricTypesEnabled = exemplarsOnAllMetricTypesEnabled;
}
@Override
public boolean accepts(String acceptHeader) {
if (acceptHeader == null) {
return false;
}
return acceptHeader.contains("application/openmetrics-text");
}
@Override
public String getContentType() {
return CONTENT_TYPE;
}
public void write(OutputStream out, MetricSnapshots metricSnapshots) throws IOException {
OutputStreamWriter writer = new OutputStreamWriter(out, StandardCharsets.UTF_8);
for (MetricSnapshot snapshot : metricSnapshots) {
if (snapshot.getData().size() > 0) {
if (snapshot instanceof CounterSnapshot) {
writeCounter(writer, (CounterSnapshot) snapshot);
} else if (snapshot instanceof GaugeSnapshot) {
writeGauge(writer, (GaugeSnapshot) snapshot);
} else if (snapshot instanceof HistogramSnapshot) {
writeHistogram(writer, (HistogramSnapshot) snapshot);
} else if (snapshot instanceof SummarySnapshot) {
writeSummary(writer, (SummarySnapshot) snapshot);
} else if (snapshot instanceof InfoSnapshot) {
writeInfo(writer, (InfoSnapshot) snapshot);
} else if (snapshot instanceof StateSetSnapshot) {
writeStateSet(writer, (StateSetSnapshot) snapshot);
} else if (snapshot instanceof UnknownSnapshot) {
writeUnknown(writer, (UnknownSnapshot) snapshot);
}
}
}
writer.write("# EOF\n");
writer.flush();
}
private void writeCounter(OutputStreamWriter writer, CounterSnapshot snapshot) throws IOException {
MetricMetadata metadata = snapshot.getMetadata();
writeMetadata(writer, "counter", metadata);
for (CounterSnapshot.CounterDataPointSnapshot data : snapshot.getData()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), "_total", data.getLabels());
writeDouble(writer, data.getValue());
writeScrapeTimestampAndExemplar(writer, data, data.getExemplar());
writeCreated(writer, metadata, data);
}
}
private void writeGauge(OutputStreamWriter writer, GaugeSnapshot snapshot) throws IOException {
MetricMetadata metadata = snapshot.getMetadata();
writeMetadata(writer, "gauge", metadata);
for (GaugeSnapshot.GaugeDataPointSnapshot data : snapshot.getData()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels());
writeDouble(writer, data.getValue());
if (exemplarsOnAllMetricTypesEnabled) {
writeScrapeTimestampAndExemplar(writer, data, data.getExemplar());
} else {
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
}
private void writeHistogram(OutputStreamWriter writer, HistogramSnapshot snapshot) throws IOException {
MetricMetadata metadata = snapshot.getMetadata();
if (snapshot.isGaugeHistogram()) {
writeMetadata(writer, "gaugehistogram", metadata);
writeClassicHistogramBuckets(writer, metadata, "_gcount", "_gsum", snapshot.getData());
} else {
writeMetadata(writer, "histogram", metadata);
writeClassicHistogramBuckets(writer, metadata, "_count", "_sum", snapshot.getData());
}
}
private void writeClassicHistogramBuckets(OutputStreamWriter writer, MetricMetadata metadata, String countSuffix, String sumSuffix, List dataList) throws IOException {
for (HistogramSnapshot.HistogramDataPointSnapshot data : dataList) {
ClassicHistogramBuckets buckets = getClassicBuckets(data);
Exemplars exemplars = data.getExemplars();
long cumulativeCount = 0;
for (int i = 0; i < buckets.size(); i++) {
cumulativeCount += buckets.getCount(i);
writeNameAndLabels(writer, metadata.getPrometheusName(), "_bucket", data.getLabels(), "le", buckets.getUpperBound(i));
writeLong(writer, cumulativeCount);
Exemplar exemplar;
if (i == 0) {
exemplar = exemplars.get(Double.NEGATIVE_INFINITY, buckets.getUpperBound(i));
} else {
exemplar = exemplars.get(buckets.getUpperBound(i - 1), buckets.getUpperBound(i));
}
writeScrapeTimestampAndExemplar(writer, data, exemplar);
}
if (data.hasCount() && data.hasSum()) {
// In OpenMetrics format, histogram _count and _sum are either both present or both absent.
// While Prometheus allows Exemplars for histogram's _count and _sum now, we don't
// use Exemplars here to be backwards compatible with previous behavior.
writeCountAndSum(writer, metadata, data, countSuffix, sumSuffix, Exemplars.EMPTY);
}
writeCreated(writer, metadata, data);
}
}
private ClassicHistogramBuckets getClassicBuckets(HistogramSnapshot.HistogramDataPointSnapshot data) {
if (data.getClassicBuckets().isEmpty()) {
return ClassicHistogramBuckets.of(
new double[]{Double.POSITIVE_INFINITY},
new long[]{data.getCount()}
);
} else {
return data.getClassicBuckets();
}
}
private void writeSummary(OutputStreamWriter writer, SummarySnapshot snapshot) throws IOException {
boolean metadataWritten = false;
MetricMetadata metadata = snapshot.getMetadata();
for (SummarySnapshot.SummaryDataPointSnapshot data : snapshot.getData()) {
if (data.getQuantiles().size() == 0 && !data.hasCount() && !data.hasSum()) {
continue;
}
if (!metadataWritten) {
writeMetadata(writer, "summary", metadata);
metadataWritten = true;
}
Exemplars exemplars = data.getExemplars();
// Exemplars for summaries are new, and there's no best practice yet which Exemplars to choose for which
// time series. We select exemplars[0] for _count, exemplars[1] for _sum, and exemplars[2...] for the
// quantiles, all indexes modulo exemplars.length.
int exemplarIndex = 1;
for (Quantile quantile : data.getQuantiles()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels(), "quantile", quantile.getQuantile());
writeDouble(writer, quantile.getValue());
if (exemplars.size() > 0 && exemplarsOnAllMetricTypesEnabled) {
exemplarIndex = (exemplarIndex + 1) % exemplars.size();
writeScrapeTimestampAndExemplar(writer, data, exemplars.get(exemplarIndex));
} else {
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
// Unlike histograms, summaries can have only a count or only a sum according to OpenMetrics.
writeCountAndSum(writer, metadata, data, "_count", "_sum", exemplars);
writeCreated(writer, metadata, data);
}
}
private void writeInfo(OutputStreamWriter writer, InfoSnapshot snapshot) throws IOException {
MetricMetadata metadata = snapshot.getMetadata();
writeMetadata(writer, "info", metadata);
for (InfoSnapshot.InfoDataPointSnapshot data : snapshot.getData()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), "_info", data.getLabels());
writer.write("1");
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
private void writeStateSet(OutputStreamWriter writer, StateSetSnapshot snapshot) throws IOException {
MetricMetadata metadata = snapshot.getMetadata();
writeMetadata(writer, "stateset", metadata);
for (StateSetSnapshot.StateSetDataPointSnapshot data : snapshot.getData()) {
for (int i = 0; i < data.size(); i++) {
writer.write(metadata.getPrometheusName());
writer.write('{');
for (int j = 0; j < data.getLabels().size(); j++) {
if (j > 0) {
writer.write(",");
}
writer.write(data.getLabels().getPrometheusName(j));
writer.write("=\"");
writeEscapedLabelValue(writer, data.getLabels().getValue(j));
writer.write("\"");
}
if (!data.getLabels().isEmpty()) {
writer.write(",");
}
writer.write(metadata.getPrometheusName());
writer.write("=\"");
writeEscapedLabelValue(writer, data.getName(i));
writer.write("\"} ");
if (data.isTrue(i)) {
writer.write("1");
} else {
writer.write("0");
}
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
}
private void writeUnknown(OutputStreamWriter writer, UnknownSnapshot snapshot) throws IOException {
MetricMetadata metadata = snapshot.getMetadata();
writeMetadata(writer, "unknown", metadata);
for (UnknownSnapshot.UnknownDataPointSnapshot data : snapshot.getData()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), null, data.getLabels());
writeDouble(writer, data.getValue());
if (exemplarsOnAllMetricTypesEnabled) {
writeScrapeTimestampAndExemplar(writer, data, data.getExemplar());
} else {
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
}
private void writeCountAndSum(OutputStreamWriter writer, MetricMetadata metadata, DistributionDataPointSnapshot data, String countSuffix, String sumSuffix, Exemplars exemplars) throws IOException {
int exemplarIndex = 0;
if (data.hasCount()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), countSuffix, data.getLabels());
writeLong(writer, data.getCount());
if (exemplars.size() > 0) {
writeScrapeTimestampAndExemplar(writer, data, exemplars.get(exemplarIndex));
exemplarIndex = exemplarIndex + 1 % exemplars.size();
} else {
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
if (data.hasSum()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), sumSuffix, data.getLabels());
writeDouble(writer, data.getSum());
if (exemplars.size() > 0) {
writeScrapeTimestampAndExemplar(writer, data, exemplars.get(exemplarIndex));
} else {
writeScrapeTimestampAndExemplar(writer, data, null);
}
}
}
private void writeCreated(OutputStreamWriter writer, MetricMetadata metadata, DataPointSnapshot data) throws IOException {
if (createdTimestampsEnabled && data.hasCreatedTimestamp()) {
writeNameAndLabels(writer, metadata.getPrometheusName(), "_created", data.getLabels());
writeTimestamp(writer, data.getCreatedTimestampMillis());
if (data.hasScrapeTimestamp()) {
writer.write(' ');
writeTimestamp(writer, data.getScrapeTimestampMillis());
}
writer.write('\n');
}
}
private void writeNameAndLabels(OutputStreamWriter writer, String name, String suffix, Labels labels) throws IOException {
writeNameAndLabels(writer, name, suffix, labels, null, 0.0);
}
private void writeNameAndLabels(OutputStreamWriter writer, String name, String suffix, Labels labels,
String additionalLabelName, double additionalLabelValue) throws IOException {
writer.write(name);
if (suffix != null) {
writer.write(suffix);
}
if (!labels.isEmpty() || additionalLabelName != null) {
writeLabels(writer, labels, additionalLabelName, additionalLabelValue);
}
writer.write(' ');
}
private void writeScrapeTimestampAndExemplar(OutputStreamWriter writer, DataPointSnapshot data, Exemplar exemplar) throws IOException {
if (data.hasScrapeTimestamp()) {
writer.write(' ');
writeTimestamp(writer, data.getScrapeTimestampMillis());
}
if (exemplar != null) {
writer.write(" # ");
writeLabels(writer, exemplar.getLabels(), null, 0);
writer.write(' ');
writeDouble(writer, exemplar.getValue());
if (exemplar.hasTimestamp()) {
writer.write(' ');
writeTimestamp(writer, exemplar.getTimestampMillis());
}
}
writer.write('\n');
}
private void writeMetadata(OutputStreamWriter writer, String typeName, MetricMetadata metadata) throws IOException {
writer.write("# TYPE ");
writer.write(metadata.getPrometheusName());
writer.write(' ');
writer.write(typeName);
writer.write('\n');
if (metadata.getUnit() != null) {
writer.write("# UNIT ");
writer.write(metadata.getPrometheusName());
writer.write(' ');
writeEscapedLabelValue(writer, metadata.getUnit().toString());
writer.write('\n');
}
if (metadata.getHelp() != null && !metadata.getHelp().isEmpty()) {
writer.write("# HELP ");
writer.write(metadata.getPrometheusName());
writer.write(' ');
writeEscapedLabelValue(writer, metadata.getHelp());
writer.write('\n');
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy