add option to skip scope_info metric

Author: zeitlinger

exporters/prometheus/src/main/java/io/opentelemetry/exporter/prometheus/Otel2PrometheusConverter.java

@@ -82,7 +82,7 @@ final class Otel2PrometheusConverter {
   private static final long NANOS_PER_MILLISECOND = TimeUnit.MILLISECONDS.toNanos(1);
   static final int MAX_CACHE_SIZE = 10;
 
-  private final boolean otelScopeEnabled;
+  private final OtelScopeMode otelScopeMode;
   @Nullable private final Predicate<String> allowedResourceAttributesFilter;
 
   /**
@@ -94,14 +94,14 @@ final class Otel2PrometheusConverter {
   /**
    * Constructor with feature flag parameter.
    *
-   * @param otelScopeEnabled enable generation of the OpenTelemetry instrumentation scope info
+   * @param otelScopeMode enable generation of the OpenTelemetry instrumentation scope info
    *     metric and labels.
    * @param allowedResourceAttributesFilter if not {@code null}, resource attributes with keys
    *     matching this predicate will be added as labels on each exported metric
    */
   Otel2PrometheusConverter(
-      boolean otelScopeEnabled, @Nullable Predicate<String> allowedResourceAttributesFilter) {
-    this.otelScopeEnabled = otelScopeEnabled;
+      OtelScopeMode otelScopeMode, @Nullable Predicate<String> allowedResourceAttributesFilter) {
+    this.otelScopeMode = otelScopeMode;
     this.allowedResourceAttributesFilter = allowedResourceAttributesFilter;
     this.resourceAttributesToAllowedKeysCache =
         allowedResourceAttributesFilter != null
@@ -125,14 +125,14 @@ MetricSnapshots convert(@Nullable Collection<MetricData> metricDataCollection) {
       if (resource == null) {
         resource = metricData.getResource();
       }
-      if (otelScopeEnabled && !metricData.getInstrumentationScopeInfo().getAttributes().isEmpty()) {
+      if (otelScopeMode.isEnabled() && !metricData.getInstrumentationScopeInfo().getAttributes().isEmpty()) {
         scopes.add(metricData.getInstrumentationScopeInfo());
       }
     }
     if (resource != null) {
       putOrMerge(snapshotsByName, makeTargetInfo(resource));
     }
-    if (otelScopeEnabled && !scopes.isEmpty()) {
+    if (otelScopeMode.isScopeInfoEnabled() && !scopes.isEmpty()) {
       putOrMerge(snapshotsByName, makeScopeInfo(scopes));
     }
     return new MetricSnapshots(snapshotsByName.values());
@@ -457,8 +457,8 @@ private InfoSnapshot makeScopeInfo(Set<InstrumentationScopeInfo> scopes) {
    * Convert OpenTelemetry attributes to Prometheus labels.
    *
    * @param resource optional resource (attributes) to be converted.
-   * @param scope will be converted to {@code otel_scope_*} labels if {@code otelScopeEnabled} is
-   *     {@code true}.
+   * @param scope will be converted to {@code otel_scope_*} labels if {@code otelScopeMode} is
+   *     {@link  OtelScopeMode#isEnabled()}.
    * @param attributes the attributes to be converted.
    * @param additionalAttributes optional list of key/value pairs, may be empty.
    */
@@ -485,7 +485,7 @@ private Labels convertAttributes(
           requireNonNull(additionalAttributes[i]), additionalAttributes[i + 1]);
     }
 
-    if (otelScopeEnabled && scope != null) {
+    if (otelScopeMode.isEnabled() && scope != null) {
       labelNameToValue.putIfAbsent(OTEL_SCOPE_NAME, scope.getName());
       if (scope.getVersion() != null) {
         labelNameToValue.putIfAbsent(OTEL_SCOPE_VERSION, scope.getVersion());

exporters/prometheus/src/main/java/io/opentelemetry/exporter/prometheus/OtelScopeMode.java

@@ -0,0 +1,26 @@
+package io.opentelemetry.exporter.prometheus;
+
+public enum OtelScopeMode {
+  /** No scope information is exported. */
+  DISABLED,
+  /**
+   * Only the labels of the metrics are exported, but not the scope_info info metrics.
+   *
+   * <p>This will eventually be the default mode, but is opt-in for now.
+   */
+  LABELS_ONLY,
+  /**
+   * Both labels and scope_info are exported.
+   *
+   * <p>This is the default mode.
+   */
+  LABELS_AND_SCOPE_INFO;
+
+  boolean isEnabled() {
+    return this != DISABLED;
+  }
+
+  boolean isScopeInfoEnabled() {
+    return this == LABELS_AND_SCOPE_INFO;
+  }
+}

exporters/prometheus/src/main/java/io/opentelemetry/exporter/prometheus/PrometheusHttpServer.java

@@ -72,7 +72,7 @@ public static PrometheusHttpServerBuilder builder() {
       int port,
       @Nullable ExecutorService executor,
       PrometheusRegistry prometheusRegistry,
-      boolean otelScopeEnabled,
+      OtelScopeMode otelScopeMode,
       @Nullable Predicate<String> allowedResourceAttributesFilter,
       MemoryMode memoryMode,
       @Nullable HttpHandler defaultHandler,
@@ -86,7 +86,7 @@ public static PrometheusHttpServerBuilder builder() {
     this.defaultAggregationSelector = defaultAggregationSelector;
     this.builder = builder;
     this.prometheusMetricReader =
-        new PrometheusMetricReader(otelScopeEnabled, allowedResourceAttributesFilter);
+        new PrometheusMetricReader(otelScopeMode, allowedResourceAttributesFilter);
     this.prometheusRegistry = prometheusRegistry;
     prometheusRegistry.register(prometheusMetricReader);
     // When memory mode is REUSABLE_DATA, concurrent reads lead to data corruption. To prevent this,

exporters/prometheus/src/main/java/io/opentelemetry/exporter/prometheus/PrometheusHttpServerBuilder.java

@@ -30,7 +30,7 @@ public final class PrometheusHttpServerBuilder {
   private String host = DEFAULT_HOST;
   private int port = DEFAULT_PORT;
   private PrometheusRegistry prometheusRegistry = new PrometheusRegistry();
-  private boolean otelScopeEnabled = true;
+  private OtelScopeMode otelScopeMode = OtelScopeMode.LABELS_AND_SCOPE_INFO;
   @Nullable private Predicate<String> allowedResourceAttributesFilter;
   @Nullable private ExecutorService executor;
   private MemoryMode memoryMode = DEFAULT_MEMORY_MODE;
@@ -45,7 +45,7 @@ public final class PrometheusHttpServerBuilder {
     this.host = builder.host;
     this.port = builder.port;
     this.prometheusRegistry = builder.prometheusRegistry;
-    this.otelScopeEnabled = builder.otelScopeEnabled;
+    this.otelScopeMode = builder.otelScopeMode;
     this.allowedResourceAttributesFilter = builder.allowedResourceAttributesFilter;
     this.executor = builder.executor;
     this.memoryMode = builder.memoryMode;
@@ -85,8 +85,8 @@ public PrometheusHttpServerBuilder setPrometheusRegistry(PrometheusRegistry prom
 
   /** Set if the {@code otel_scope_*} attributes are generated. Default is {@code true}. */
   @SuppressWarnings("UnusedReturnValue")
-  public PrometheusHttpServerBuilder setOtelScopeEnabled(boolean otelScopeEnabled) {
-    this.otelScopeEnabled = otelScopeEnabled;
+  public PrometheusHttpServerBuilder setOtelScopeMode(OtelScopeMode otelScopeMode) {
+    this.otelScopeMode = otelScopeMode;
     return this;
   }
 
@@ -176,7 +176,7 @@ public PrometheusHttpServer build() {
         port,
         executor,
         prometheusRegistry,
-        otelScopeEnabled,
+        otelScopeMode,
         allowedResourceAttributesFilter,
         memoryMode,
         defaultHandler,

exporters/prometheus/src/main/java/io/opentelemetry/exporter/prometheus/PrometheusMetricReader.java

@@ -29,11 +29,11 @@ public class PrometheusMetricReader implements MetricReader, MultiCollector {
   private final Otel2PrometheusConverter converter;
 
   // TODO: refactor to public static create or builder pattern to align with project style
-  /** See {@link Otel2PrometheusConverter#Otel2PrometheusConverter(boolean, Predicate)}. */
+  /** See {@link Otel2PrometheusConverter#Otel2PrometheusConverter(OtelScopeMode, Predicate)}. */
   public PrometheusMetricReader(
-      boolean otelScopeEnabled, @Nullable Predicate<String> allowedResourceAttributesFilter) {
+      OtelScopeMode otelScopeMode, @Nullable Predicate<String> allowedResourceAttributesFilter) {
     this.converter =
-        new Otel2PrometheusConverter(otelScopeEnabled, allowedResourceAttributesFilter);
+        new Otel2PrometheusConverter(otelScopeMode, allowedResourceAttributesFilter);
   }
 
   @Override

exporters/prometheus/src/test/java/io/opentelemetry/exporter/prometheus/Otel2PrometheusConverterTest.java

@@ -71,7 +71,7 @@ class Otel2PrometheusConverterTest {
   private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
 
   private final Otel2PrometheusConverter converter =
-      new Otel2PrometheusConverter(true, /* allowedResourceAttributesFilter= */ null);
+      new Otel2PrometheusConverter(OtelScopeMode.LABELS_AND_SCOPE_INFO, /* allowedResourceAttributesFilter= */ null);
 
   @ParameterizedTest
   @MethodSource("metricMetadataArgs")
@@ -201,7 +201,7 @@ void resourceAttributesAddition(
       throws IOException {
 
     Otel2PrometheusConverter converter =
-        new Otel2PrometheusConverter(true, allowedResourceAttributesFilter);
+        new Otel2PrometheusConverter(OtelScopeMode.LABELS_AND_SCOPE_INFO, allowedResourceAttributesFilter);
 
     ByteArrayOutputStream out = new ByteArrayOutputStream();
     MetricSnapshots snapshots = converter.convert(Collections.singletonList(metricData));
@@ -501,7 +501,7 @@ void validateCacheIsBounded() {
         };
 
     Otel2PrometheusConverter otel2PrometheusConverter =
-        new Otel2PrometheusConverter(true, /* allowedResourceAttributesFilter= */ countPredicate);
+        new Otel2PrometheusConverter(OtelScopeMode.LABELS_AND_SCOPE_INFO, /* allowedResourceAttributesFilter= */ countPredicate);
 
     // Create 20 different metric data objects with 2 different resource attributes;
     Resource resource1 = Resource.builder().put("cluster", "cluster1").build();

exporters/prometheus/src/test/java/io/opentelemetry/exporter/prometheus/PrometheusHttpServerTest.java

@@ -528,7 +528,7 @@ void toBuilder() {
     PrometheusHttpServerBuilder builder = PrometheusHttpServer.builder();
     builder.setHost("localhost");
     builder.setPort(1234);
-    builder.setOtelScopeEnabled(false);
+    builder.setOtelScopeMode(OtelScopeMode.DISABLED);
 
     Predicate<String> resourceAttributesFilter = s -> false;
     builder.setAllowedResourceAttributesFilter(resourceAttributesFilter);
@@ -555,7 +555,7 @@ public Result authenticate(HttpExchange exchange) {
         .isInstanceOf(PrometheusHttpServerBuilder.class)
         .hasFieldOrPropertyWithValue("host", "localhost")
         .hasFieldOrPropertyWithValue("port", 1234)
-        .hasFieldOrPropertyWithValue("otelScopeEnabled", false)
+        .hasFieldOrPropertyWithValue("otelScopeMode", OtelScopeMode.DISABLED)
         .hasFieldOrPropertyWithValue("allowedResourceAttributesFilter", resourceAttributesFilter)
         .hasFieldOrPropertyWithValue("executor", executor)
         .hasFieldOrPropertyWithValue("prometheusRegistry", prometheusRegistry)

exporters/prometheus/src/test/java/io/opentelemetry/exporter/prometheus/PrometheusMetricReaderTest.java

@@ -61,7 +61,7 @@ class PrometheusMetricReaderTest {
   void setUp() {
     this.testClock.setTime(Instant.ofEpochMilli((System.currentTimeMillis() / 100) * 100));
     this.createdTimestamp = convertTimestamp(testClock.now());
-    this.reader = new PrometheusMetricReader(true, /* allowedResourceAttributesFilter= */ null);
+    this.reader = new PrometheusMetricReader(OtelScopeMode.LABELS_AND_SCOPE_INFO, /* allowedResourceAttributesFilter= */ null);
     this.meter =
         SdkMeterProvider.builder()
             .setClock(testClock)
@@ -776,7 +776,7 @@ void exponentialHistogramBucketConversion() {
       int otelScale = random.nextInt(24) - 4;
       int prometheusScale = Math.min(otelScale, 8);
       PrometheusMetricReader reader =
-          new PrometheusMetricReader(true, /* allowedResourceAttributesFilter= */ null);
+          new PrometheusMetricReader(OtelScopeMode.LABELS_AND_SCOPE_INFO, /* allowedResourceAttributesFilter= */ null);
       Meter meter =
           SdkMeterProvider.builder()
               .registerMetricReader(reader)
@@ -1029,7 +1029,7 @@ void otelScopeComplete() throws IOException {
   @Test
   void otelScopeDisabled() throws IOException {
     PrometheusMetricReader reader =
-        new PrometheusMetricReader(false, /* allowedResourceAttributesFilter= */ null);
+        new PrometheusMetricReader(OtelScopeMode.DISABLED, /* allowedResourceAttributesFilter= */ null);
     Meter meter =
         SdkMeterProvider.builder()
             .setClock(testClock)
@@ -1060,7 +1060,7 @@ void otelScopeDisabled() throws IOException {
   void addResourceAttributesWorks() throws IOException {
     PrometheusMetricReader reader =
         new PrometheusMetricReader(
-            true, /* allowedResourceAttributesFilter= */ Predicates.is("cluster"));
+            OtelScopeMode.LABELS_AND_SCOPE_INFO, /* allowedResourceAttributesFilter= */ Predicates.is("cluster"));
     Meter meter =
         SdkMeterProvider.builder()
             .setClock(testClock)