Use http.route in HttpServerMetrics (#5266)

* Use http.route in HttpServerMetrics

* remove http.target fallback

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/http/HttpRouteHolder.java

@@ -146,7 +146,6 @@ private boolean isBetterRoute(String name) {
  return name.length() > routeLength;
  }
 
- // TODO: use that in HttpServerMetrics
  /**
  * Returns the {@code http.route} attribute value that's stored in the passed {@code context}, or
  * null if it was not set before.

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/http/HttpServerMetrics.java

@@ -18,7 +18,9 @@
 import io.opentelemetry.instrumentation.api.annotations.UnstableApi;
 import io.opentelemetry.instrumentation.api.instrumenter.RequestListener;
 import io.opentelemetry.instrumentation.api.instrumenter.RequestMetrics;
+import io.opentelemetry.semconv.trace.attributes.SemanticAttributes;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -49,8 +51,14 @@ public static RequestMetrics get() {
 
  private final LongUpDownCounter activeRequests;
  private final DoubleHistogram duration;
+ private final Function<Context, String> httpRouteHolderGetter;
 
  private HttpServerMetrics(Meter meter) {
+ this(meter, HttpRouteHolder::getRoute);
+ }
+
+ // visible for tests
+ HttpServerMetrics(Meter meter, Function<Context, String> httpRouteHolderGetter) {
  activeRequests =
  meter
  .upDownCounterBuilder("http.server.active_requests")
@@ -64,6 +72,8 @@ private HttpServerMetrics(Meter meter) {
  .setUnit("ms")
  .setDescription("The duration of the inbound HTTP request")
  .build();
+
+ this.httpRouteHolderGetter = httpRouteHolderGetter;
  }
 
  @Override
@@ -86,10 +96,19 @@ public void end(Context context, Attributes endAttributes, long endNanos) {
  activeRequests.add(-1, applyActiveRequestsView(state.startAttributes()));
  duration.record(
  (endNanos - state.startTimeNanos()) / NANOS_PER_MS,
- applyServerDurationView(state.startAttributes(), endAttributes),
+ applyServerDurationView(state.startAttributes(), addHttpRoute(context, endAttributes)),
  context);
  }
 
+ // TODO: the http.route should be extracted by the AttributesExtractor, HttpServerMetrics should
+ // not access the context to get it
+ private Attributes addHttpRoute(Context context, Attributes endAttributes) {
+ String route = httpRouteHolderGetter.apply(context);
+ return route == null
+ ? endAttributes
+ : endAttributes.toBuilder().put(SemanticAttributes.HTTP_ROUTE, route).build();
+ }
+
  @AutoValue
  abstract static class State {
 

instrumentation-api/src/main/java/io/opentelemetry/instrumentation/api/instrumenter/http/TemporaryMetricsView.java

@@ -8,7 +8,6 @@
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
 import io.opentelemetry.api.common.AttributesBuilder;
-import io.opentelemetry.instrumentation.api.config.Config;
 import io.opentelemetry.semconv.trace.attributes.SemanticAttributes;
 import java.util.HashSet;
 import java.util.Set;
@@ -19,19 +18,9 @@
 @SuppressWarnings("rawtypes")
 final class TemporaryMetricsView {
 
- // TODO (trask) remove this once http.route is captured consistently
- //
- // this is not enabled by default because it falls back to http.target (which can be high
- // cardinality) when http.route is not available
- private static final boolean USE_HTTP_TARGET_FALLBACK =
- Config.get()
- .getBoolean("otel.instrumentation.metrics.experimental.use-http-target-fallback", false);
-
  private static final Set<AttributeKey> durationAlwaysInclude = buildDurationAlwaysInclude();
  private static final Set<AttributeKey> durationClientView = buildDurationClientView();
  private static final Set<AttributeKey> durationServerView = buildDurationServerView();
- private static final Set<AttributeKey> durationServerFallbackView =
- buildDurationServerFallbackView();
  private static final Set<AttributeKey> activeRequestsView = buildActiveRequestsView();
 
  private static Set<AttributeKey> buildDurationAlwaysInclude() {
@@ -65,19 +54,6 @@ private static Set<AttributeKey> buildDurationServerView() {
  return view;
  }
 
- private static Set<AttributeKey> buildDurationServerFallbackView() {
- // We pull identifying attributes according to:
- // https:/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/semantic_conventions/http-metrics.md#attribute-alternatives
- // With the following caveat:
- // - we always rely on http.route + http.host in this repository.
- // - we prefer http.route (which is scrubbed) over http.target (which is not scrubbed).
- Set<AttributeKey> view = new HashSet<>(durationAlwaysInclude);
- view.add(SemanticAttributes.HTTP_SCHEME);
- view.add(SemanticAttributes.HTTP_HOST);
- view.add(SemanticAttributes.HTTP_TARGET);
- return view;
- }
-
  private static Set<AttributeKey> buildActiveRequestsView() {
  // the list of included metrics is from
  // https:/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/semantic_conventions/http-metrics.md#attributes
@@ -97,21 +73,10 @@ static Attributes applyClientDurationView(Attributes startAttributes, Attributes
  return filtered.build();
  }
 
- private static <T> boolean containsAttribute(
- AttributeKey<T> key, Attributes startAttributes, Attributes endAttributes) {
- return startAttributes.get(key) != null || endAttributes.get(key) != null;
- }
-
  static Attributes applyServerDurationView(Attributes startAttributes, Attributes endAttributes) {
- Set<AttributeKey> fullSet = durationServerView;
- // Use http.target when http.route is not available.
- if (USE_HTTP_TARGET_FALLBACK
- && !containsAttribute(SemanticAttributes.HTTP_ROUTE, startAttributes, endAttributes)) {
- fullSet = durationServerFallbackView;
- }
  AttributesBuilder filtered = Attributes.builder();
- applyView(filtered, startAttributes, fullSet);
- applyView(filtered, endAttributes, fullSet);
+ applyView(filtered, startAttributes, durationServerView);
+ applyView(filtered, endAttributes, durationServerView);
  return filtered.build();
  }
 

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/instrumenter/http/HttpServerMetricsTest.java

@@ -156,6 +156,49 @@ void collectsMetrics() {
  .satisfiesExactly(point -> assertThat(point).hasSum(300 /* millis */)));
  }
 
+ @Test
+ void collectsHttpRouteFromContext() {
+ // given
+ InMemoryMetricReader metricReader = InMemoryMetricReader.create();
+ SdkMeterProvider meterProvider =
+ SdkMeterProvider.builder()
+ .registerMetricReader(metricReader)
+ .setMinimumCollectionInterval(Duration.ZERO)
+ .build();
+
+ RequestListener listener = new HttpServerMetrics(meterProvider.get("test"), c -> "/test/{id}");
+
+ Attributes requestAttributes =
+ Attributes.builder().put("http.host", "host").put("http.scheme", "https").build();
+
+ Attributes responseAttributes = Attributes.empty();
+
+ Context parentContext = Context.root();
+
+ // when
+ Context context = listener.start(parentContext, requestAttributes, nanos(100));
+ listener.end(context, responseAttributes, nanos(200));
+
+ // then
+ assertThat(metricReader.collectAllMetrics())
+ .anySatisfy(
+ metric ->
+ assertThat(metric)
+ .hasName("http.server.duration")
+ .hasUnit("ms")
+ .hasDoubleHistogram()
+ .points()
+ .satisfiesExactly(
+ point ->
+ assertThat(point)
+ .hasSum(100 /* millis */)
+ .attributes()
+ .containsOnly(
+ attributeEntry("http.scheme", "https"),
+ attributeEntry("http.host", "host"),
+ attributeEntry("http.route", "/test/{id}"))));
+ }
+
  private static long nanos(int millis) {
  return TimeUnit.MILLISECONDS.toNanos(millis);
  }

instrumentation-api/src/test/java/io/opentelemetry/instrumentation/api/instrumenter/http/TemporaryMetricsViewTest.java

@@ -109,37 +109,6 @@ public void shouldApplyServerDurationView_withRoute() {
  attributeEntry(SemanticAttributes.HTTP_STATUS_CODE.getKey(), 500));
  }
 
- @Test
- public void shouldApplyServerDurationView_withTarget() {
- Attributes startAttributes =
- Attributes.builder()
- .put(SemanticAttributes.HTTP_METHOD, "GET")
- .put(SemanticAttributes.HTTP_URL, "https://somehost/high/cardinality/12345")
- .put(SemanticAttributes.HTTP_SCHEME, "https")
- .put(SemanticAttributes.HTTP_HOST, "somehost")
- .put(SemanticAttributes.HTTP_SERVER_NAME, "somehost")
- .put(
- SemanticAttributes.HTTP_TARGET, "/somehost/high/cardinality/12345;jsessionId=12145")
- .put(SemanticAttributes.NET_HOST_NAME, "somehost")
- .put(SemanticAttributes.NET_HOST_PORT, 443)
- .build();
-
- Attributes endAttributes =
- Attributes.builder()
- .put(SemanticAttributes.HTTP_STATUS_CODE, 500)
- .put(SemanticAttributes.NET_PEER_NAME, "somehost2")
- .put(SemanticAttributes.NET_PEER_IP, "127.0.0.1")
- .put(SemanticAttributes.NET_PEER_PORT, 443)
- .build();
-
- OpenTelemetryAssertions.assertThat(applyServerDurationView(startAttributes, endAttributes))
- .containsOnly(
- attributeEntry(SemanticAttributes.HTTP_SCHEME.getKey(), "https"),
- attributeEntry(SemanticAttributes.HTTP_HOST.getKey(), "somehost"),
- attributeEntry(SemanticAttributes.HTTP_METHOD.getKey(), "GET"),
- attributeEntry(SemanticAttributes.HTTP_STATUS_CODE.getKey(), 500));
- }
-
  @Test
  public void shouldApplyActiveRequestsView() {
  Attributes attributes =