1 files changed, 76 insertions, 0 deletions
diff --git a/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusUtil.java b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusUtil.java
new file mode 100644
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+++ b/metrics-proxy/src/main/java/ai/vespa/metricsproxy/metric/model/prometheus/PrometheusUtil.java
@@ -0,0 +1,76 @@
+/*
+ * Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+ */
+
+package ai.vespa.metricsproxy.metric.model.prometheus;
+
+import ai.vespa.metricsproxy.metric.model.MetricsPacket;
+import ai.vespa.metricsproxy.metric.model.ServiceId;
+import io.prometheus.client.Collector;
+import io.prometheus.client.Collector.MetricFamilySamples;
+import io.prometheus.client.Collector.MetricFamilySamples.Sample;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+
+/**
+ * @author yj-jtakagi
+ * @author gjoranv
+ */
+public class PrometheusUtil {
+
+    public static PrometheusModel toPrometheusModel(List<MetricsPacket> metricsPackets) {
+        Map<ServiceId, List<MetricsPacket>> packetsByService = metricsPackets.stream()
+                .collect(Collectors.groupingBy(packet -> packet.service));
+
+        List<MetricFamilySamples> metricFamilySamples = new ArrayList<>(packetsByService.size());
+
+        packetsByService.forEach(((serviceId, packets) -> {
+            Map<String, List<Sample>> samples = new HashMap<>();
+
+            var serviceName = Collector.sanitizeMetricName(serviceId.id);
+            for (var packet : packets) {
+                var dimensions = packet.dimensions();
+                List<String> labels = new ArrayList<>(dimensions.size());
+                List<String> labelValues = new ArrayList<>(dimensions.size());
+                for (var entry : dimensions.entrySet()) {
+                    var labelName = Collector.sanitizeMetricName(entry.getKey().id);
+                    labels.add(labelName);
+                    labelValues.add(entry.getValue());
+                }
+
+                for (var metric : packet.metrics().entrySet()) {
+                    var metricName = serviceName + "_" + Collector.sanitizeMetricName(metric.getKey().id);
+                    List<Sample> sampleList;
+                    if (samples.containsKey(metricName)) {
+                        sampleList = samples.get(metricName);
+                    } else {
+                        sampleList = new ArrayList<>();
+                        samples.put(metricName, sampleList);
+                        metricFamilySamples.add(new MetricFamilySamples(metricName, Collector.Type.UNTYPED, "", sampleList));
+                    }
+                    sampleList.add(new Sample(metricName, labels, labelValues, metric.getValue().doubleValue(), packet.timestamp * 1000));
+                }
+            }
+            // convert status message to 0,1 metric
+            var firstPacket = packets.get(0);
+            String statusMetricName = serviceName + "_status";
+            // MetricsPacket status 0 means OK, but it's the opposite in Prometheus.
+            double statusMetricValue = (firstPacket.statusCode == 0) ? 1.0 : 0.0;
+            List<Sample> sampleList = singletonList(new Sample(statusMetricName, emptyList(), emptyList(),
+                                                               statusMetricValue, firstPacket.timestamp * 1000));
+            metricFamilySamples.add(new MetricFamilySamples(statusMetricName, Collector.Type.UNTYPED, "status of service", sampleList));
+        }));
+
+        return new PrometheusModel(metricFamilySamples);
+    }
+
+}