Allow customizing PrometheusProperties via PrometheusConfig

gradle/libs.versions.toml

@@ -69,7 +69,7 @@ newrelic-api = "5.14.0"
 # Kotlin 1.7 sample will fail from OkHttp 4.12.0 due to okio dependency being a Kotlin 1.9 module
 okhttp = "4.11.0"
 postgre = "42.7.2"
-prometheus = "1.2.0"
+prometheus = "1.2.1"
 prometheusSimpleClient = "0.16.0"
 reactor = "2022.0.16"
 rest-assured = "5.4.0"

implementations/micrometer-registry-prometheus/build.gradle

@@ -4,12 +4,11 @@ dependencies {
     api project(':micrometer-core')
 
     api('io.prometheus:prometheus-metrics-core') {
-        // We only need SpanContext from prometheus-metrics-tracer-common so we should
-        // exclude(group: 'io.prometheus', module: 'prometheus-metrics-tracer-initializer')
-        // But right now we cannot since ExemplarSampler imports SpanContextSupplier
-        exclude(group: 'io.prometheus', module: 'prometheus-metrics-tracer-otel')
-        exclude(group: 'io.prometheus', module: 'prometheus-metrics-tracer-otel-agent')
+        // We only need SpanContext from prometheus-metrics-tracer-common, we don't need
+        // prometheus-metrics-tracer-initializer nor the dependencies it pulls in
+        exclude(group: 'io.prometheus', module: 'prometheus-metrics-tracer-initializer')
     }
+    api 'io.prometheus:prometheus-metrics-tracer-common'
     implementation 'io.prometheus:prometheus-metrics-exposition-formats'
 
     testImplementation 'io.prometheus:prometheus-metrics-tracer-common'

implementations/micrometer-registry-prometheus/src/main/java/io/micrometer/prometheusmetrics/DefaultExemplarSamplerFactory.java

@@ -16,7 +16,6 @@
 package io.micrometer.prometheusmetrics;
 
 import io.prometheus.metrics.config.ExemplarsProperties;
-import io.prometheus.metrics.config.PrometheusProperties;
 import io.prometheus.metrics.core.exemplars.ExemplarSampler;
 import io.prometheus.metrics.core.exemplars.ExemplarSamplerConfig;
 import io.prometheus.metrics.tracer.common.SpanContext;
@@ -32,30 +31,31 @@
  */
 class DefaultExemplarSamplerFactory implements ExemplarSamplerFactory {
 
-    private final ExemplarsProperties exemplarProperties = PrometheusProperties.get().getExemplarProperties();
+    private final ExemplarsProperties exemplarsProperties;
 
     private final ConcurrentMap<Integer, ExemplarSamplerConfig> exemplarSamplerConfigsByNumberOfExemplars = new ConcurrentHashMap<>();
 
     private final ConcurrentMap<double[], ExemplarSamplerConfig> exemplarSamplerConfigsByHistogramUpperBounds = new ConcurrentHashMap<>();
 
     private final SpanContext spanContext;
 
-    public DefaultExemplarSamplerFactory(SpanContext spanContext) {
+    public DefaultExemplarSamplerFactory(SpanContext spanContext, ExemplarsProperties exemplarsProperties) {
         this.spanContext = spanContext;
+        this.exemplarsProperties = exemplarsProperties;
     }
 
     @Override
     public ExemplarSampler createExemplarSampler(int numberOfExemplars) {
         ExemplarSamplerConfig config = exemplarSamplerConfigsByNumberOfExemplars.computeIfAbsent(numberOfExemplars,
-                key -> new ExemplarSamplerConfig(exemplarProperties, numberOfExemplars));
+                key -> new ExemplarSamplerConfig(exemplarsProperties, numberOfExemplars));
         return new ExemplarSampler(config, spanContext);
     }
 
     @Override
     public ExemplarSampler createExemplarSampler(double[] histogramClassicUpperBounds) {
         ExemplarSamplerConfig config = exemplarSamplerConfigsByHistogramUpperBounds.computeIfAbsent(
                 histogramClassicUpperBounds,
-                key -> new ExemplarSamplerConfig(exemplarProperties, histogramClassicUpperBounds));
+                key -> new ExemplarSamplerConfig(exemplarsProperties, histogramClassicUpperBounds));
         return new ExemplarSampler(config, spanContext);
     }
 

implementations/micrometer-registry-prometheus/src/main/java/io/micrometer/prometheusmetrics/PrometheusConfig.java

@@ -15,10 +15,12 @@
  */
 package io.micrometer.prometheusmetrics;
 
+import io.micrometer.common.lang.Nullable;
 import io.micrometer.core.instrument.config.MeterRegistryConfig;
 import io.micrometer.core.instrument.config.validate.Validated;
 
 import java.time.Duration;
+import java.util.Properties;
 
 import static io.micrometer.core.instrument.config.MeterRegistryConfigValidator.checkAll;
 import static io.micrometer.core.instrument.config.MeterRegistryConfigValidator.checkRequired;
@@ -58,6 +60,19 @@ default Duration step() {
         return getDuration(this, "step").orElse(Duration.ofMinutes(1));
     }
 
+    /**
+     * @return an instance of {@link Properties} that contains Prometheus Java Client
+     * config entries, for example
+     * {@code io.prometheus.exporter.exemplarsOnAllMetricTypes=true}.
+     * @see https://prometheus.github.io/client_java/config/config/
+     */
+    @Nullable
+    default Properties prometheusProperties() {
+        Properties properties = new Properties();
+        properties.setProperty("io.prometheus.exporter.exemplarsOnAllMetricTypes", "true");
+        return properties;
+    }
+
     @Override
     default Validated<?> validate() {
         return checkAll(this, checkRequired("step", PrometheusConfig::step));

implementations/micrometer-registry-prometheus/src/main/java/io/micrometer/prometheusmetrics/PrometheusMeterRegistry.java

@@ -26,6 +26,7 @@
 import io.micrometer.core.instrument.internal.DefaultGauge;
 import io.micrometer.core.instrument.internal.DefaultMeter;
 import io.micrometer.core.instrument.util.TimeUtils;
+import io.prometheus.metrics.config.PrometheusProperties;
 import io.prometheus.metrics.config.PrometheusPropertiesLoader;
 import io.prometheus.metrics.expositionformats.ExpositionFormats;
 import io.prometheus.metrics.model.registry.PrometheusRegistry;
@@ -66,13 +67,12 @@
  */
 public class PrometheusMeterRegistry extends MeterRegistry {
 
-    private final ExpositionFormats expositionFormats = ExpositionFormats
-        .init(PrometheusPropertiesLoader.load().getExporterProperties());
-
     private final PrometheusConfig prometheusConfig;
 
     private final PrometheusRegistry registry;
 
+    private final ExpositionFormats expositionFormats;
+
     private final ConcurrentMap<String, MicrometerCollector> collectorMap = new ConcurrentHashMap<>();
 
     @Nullable
@@ -101,7 +101,11 @@ public PrometheusMeterRegistry(PrometheusConfig config, PrometheusRegistry regis
 
         this.prometheusConfig = config;
         this.registry = registry;
-        this.exemplarSamplerFactory = spanContext != null ? new DefaultExemplarSamplerFactory(spanContext) : null;
+        PrometheusProperties prometheusProperties = config.prometheusProperties() != null
+                ? PrometheusPropertiesLoader.load(config.prometheusProperties()) : PrometheusPropertiesLoader.load();
+        this.expositionFormats = ExpositionFormats.init(prometheusProperties.getExporterProperties());
+        this.exemplarSamplerFactory = spanContext != null
+                ? new DefaultExemplarSamplerFactory(spanContext, prometheusProperties.getExemplarProperties()) : null;
 
         config().namingConvention(new PrometheusNamingConvention());
         config().onMeterRemoved(this::onMeterRemoved);

implementations/micrometer-registry-prometheus/src/test/java/io/micrometer/prometheusmetrics/PrometheusMeterRegistryTest.java

@@ -17,6 +17,7 @@
 
 import io.micrometer.core.Issue;
 import io.micrometer.core.instrument.*;
+import io.micrometer.core.instrument.Timer;
 import io.micrometer.core.instrument.binder.BaseUnits;
 import io.micrometer.core.instrument.binder.jvm.JvmInfoMetrics;
 import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
@@ -30,10 +31,7 @@
 import org.junit.jupiter.api.Test;
 
 import java.time.Duration;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.List;
+import java.util.*;
 import java.util.concurrent.*;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
@@ -638,8 +636,23 @@ void openMetricsScrape() {
 
     @Test
     void openMetricsScrapeWithExemplars() throws InterruptedException {
-        PrometheusMeterRegistry registry = new PrometheusMeterRegistry(PrometheusConfig.DEFAULT, prometheusRegistry,
-                clock, new TestSpanContex());
+        PrometheusConfig prometheusConfig = new PrometheusConfig() {
+            @Override
+            public String get(String key) {
+                return null;
+            }
+
+            @Override
+            public Properties prometheusProperties() {
+                Properties properties = new Properties();
+                properties.putAll(PrometheusConfig.super.prometheusProperties());
+                properties.setProperty("io.prometheus.exemplars.sampleIntervalMilliseconds", "1");
+                return properties;
+            }
+        };
+
+        PrometheusMeterRegistry registry = new PrometheusMeterRegistry(prometheusConfig, prometheusRegistry, clock,
+                new TestSpanContex());
 
         Counter counter = Counter.builder("my.counter").register(registry);
         counter.increment();
@@ -651,18 +664,18 @@ void openMetricsScrapeWithExemplars() throws InterruptedException {
 
         Timer timerWithHistogram = Timer.builder("timer.withHistogram").publishPercentileHistogram().register(registry);
         timerWithHistogram.record(15, TimeUnit.MILLISECONDS);
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         timerWithHistogram.record(150, TimeUnit.MILLISECONDS);
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         timerWithHistogram.record(60, TimeUnit.SECONDS);
 
         Timer timerWithSlos = Timer.builder("timer.withSlos")
             .serviceLevelObjectives(Duration.ofMillis(100), Duration.ofMillis(200), Duration.ofMillis(300))
             .register(registry);
         timerWithSlos.record(Duration.ofMillis(15));
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         timerWithSlos.record(Duration.ofMillis(1_500));
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         timerWithSlos.record(Duration.ofMillis(150));
 
         DistributionSummary summary = DistributionSummary.builder("summary.noHistogram").register(registry);
@@ -674,18 +687,18 @@ void openMetricsScrapeWithExemplars() throws InterruptedException {
             .publishPercentileHistogram()
             .register(registry);
         summaryWithHistogram.record(0.15);
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         summaryWithHistogram.record(5E18);
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         summaryWithHistogram.record(15);
 
         DistributionSummary slos = DistributionSummary.builder("summary.withSlos")
             .serviceLevelObjectives(100, 200, 300)
             .register(registry);
         slos.record(10);
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         slos.record(1_000);
-        Thread.sleep(100); // sleeping 100ms since the sample interval limit is 90ms
+        Thread.sleep(5); // sleeping 5ms since the sample interval limit is 1ms
         slos.record(250);
 
         String scraped = registry.scrape("application/openmetrics-text");