Optimize advice with FilteredAttributes

api/all/src/main/java/io/opentelemetry/api/internal/ImmutableKeyValuePairs.java

@@ -274,4 +274,13 @@ public String toString() {
     sb.append("}");
     return sb.toString();
   }
+
+  /**
+   * Return the backing data array for these attributes. This is only exposed for internal use by
+   * opentelemetry authors. The contents of the array MUST NOT be modified.
+   */
+  @SuppressWarnings("AvoidObjectArrays")
+  public Object[] getData() {
+    return data;
+  }
 }

sdk/metrics/build.gradle.kts

@@ -25,6 +25,7 @@ dependencies {
 
   testImplementation(project(":sdk:testing"))
   testImplementation("com.google.guava:guava")
+  testImplementation("com.google.guava:guava-testlib")
 
   jmh(project(":sdk:trace"))
   jmh(project(":sdk:testing"))

sdk/metrics/src/jmh/java/io/opentelemetry/sdk/metrics/MetricAdviceBenchmark.java

@@ -0,0 +1,273 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.sdk.metrics;
+
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.incubator.metrics.ExtendedLongCounterBuilder;
+import io.opentelemetry.api.metrics.LongCounter;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.sdk.testing.exporter.InMemoryMetricReader;
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Level;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Param;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
+import org.openjdk.jmh.annotations.Threads;
+import org.openjdk.jmh.annotations.Warmup;
+
+@BenchmarkMode({Mode.AverageTime})
+@OutputTimeUnit(TimeUnit.NANOSECONDS)
+@Warmup(iterations = 5, time = 1)
+@Measurement(iterations = 10, time = 1)
+@Fork(1)
+public class MetricAdviceBenchmark {
+
+  static final AttributeKey<String> HTTP_REQUEST_METHOD =
+      AttributeKey.stringKey("http.request.method");
+  static final AttributeKey<String> URL_PATH = AttributeKey.stringKey("url.path");
+  static final AttributeKey<String> URL_SCHEME = AttributeKey.stringKey("url.scheme");
+  static final AttributeKey<Long> HTTP_RESPONSE_STATUS_CODE =
+      AttributeKey.longKey("http.response.status_code");
+  static final AttributeKey<String> HTTP_ROUTE = AttributeKey.stringKey("http.route");
+  static final AttributeKey<String> NETWORK_PROTOCOL_NAME =
+      AttributeKey.stringKey("network.protocol.name");
+  static final AttributeKey<Long> SERVER_PORT = AttributeKey.longKey("server.port");
+  static final AttributeKey<String> URL_QUERY = AttributeKey.stringKey("url.query");
+  static final AttributeKey<String> CLIENT_ADDRESS = AttributeKey.stringKey("client.address");
+  static final AttributeKey<String> NETWORK_PEER_ADDRESS =
+      AttributeKey.stringKey("network.peer.address");
+  static final AttributeKey<Long> NETWORK_PEER_PORT = AttributeKey.longKey("network.peer.port");
+  static final AttributeKey<String> NETWORK_PROTOCOL_VERSION =
+      AttributeKey.stringKey("network.protocol.version");
+  static final AttributeKey<String> SERVER_ADDRESS = AttributeKey.stringKey("server.address");
+  static final AttributeKey<String> USER_AGENT_ORIGINAL =
+      AttributeKey.stringKey("user_agent.original");
+
+  static final List<AttributeKey<?>> httpServerMetricAttributeKeys =
+      Arrays.asList(
+          HTTP_REQUEST_METHOD,
+          URL_SCHEME,
+          HTTP_RESPONSE_STATUS_CODE,
+          HTTP_ROUTE,
+          NETWORK_PROTOCOL_NAME,
+          SERVER_PORT,
+          NETWORK_PROTOCOL_VERSION,
+          SERVER_ADDRESS);
+
+  static Attributes httpServerMetricAttributes() {
+    return Attributes.builder()
+        .put(HTTP_REQUEST_METHOD, "GET")
+        .put(URL_SCHEME, "http")
+        .put(HTTP_RESPONSE_STATUS_CODE, 200)
+        .put(HTTP_ROUTE, "/v1/users/{id}")
+        .put(NETWORK_PROTOCOL_NAME, "http")
+        .put(SERVER_PORT, 8080)
+        .put(NETWORK_PROTOCOL_VERSION, "1.1")
+        .put(SERVER_ADDRESS, "localhost")
+        .build();
+  }
+
+  static Attributes httpServerSpanAttributes() {
+    return Attributes.builder()
+        .put(HTTP_REQUEST_METHOD, "GET")
+        .put(URL_PATH, "/v1/users/123")
+        .put(URL_SCHEME, "http")
+        .put(HTTP_RESPONSE_STATUS_CODE, 200)
+        .put(HTTP_ROUTE, "/v1/users/{id}")
+        .put(NETWORK_PROTOCOL_NAME, "http")
+        .put(SERVER_PORT, 8080)
+        .put(URL_QUERY, "with=email")
+        .put(CLIENT_ADDRESS, "192.168.0.17")
+        .put(NETWORK_PEER_ADDRESS, "192.168.0.17")
+        .put(NETWORK_PEER_PORT, 11265)
+        .put(NETWORK_PROTOCOL_VERSION, "1.1")
+        .put(SERVER_ADDRESS, "localhost")
+        .put(USER_AGENT_ORIGINAL, "okhttp/1.27.2")
+        .build();
+  }
+
+  static final Attributes CACHED_HTTP_SERVER_SPAN_ATTRIBUTES = httpServerSpanAttributes();
+
+  @State(Scope.Benchmark)
+  public static class ThreadState {
+
+    @Param InstrumentParam instrumentParam;
+
+    SdkMeterProvider meterProvider;
+
+    @Setup(Level.Iteration)
+    public void setup() {
+      meterProvider =
+          SdkMeterProvider.builder()
+              .registerMetricReader(InMemoryMetricReader.createDelta())
+              .build();
+      Meter meter = meterProvider.get("meter");
+      instrumentParam.instrument().setup(meter);
+    }
+
+    @TearDown
+    public void tearDown() {
+      meterProvider.shutdown().join(10, TimeUnit.SECONDS);
+    }
+  }
+
+  @Benchmark
+  @Threads(1)
+  public void record(ThreadState threadState) {
+    threadState.instrumentParam.instrument().record(1);
+  }
+
+  @SuppressWarnings("ImmutableEnumChecker")
+  public enum InstrumentParam {
+    /**
+     * Record HTTP span attributes without advice. This baseline shows the CPU and memory allocation
+     * independent of advice.
+     */
+    NO_ADVICE_ALL_ATTRIBUTES(
+        new Instrument() {
+          private LongCounter counter;
+
+          @Override
+          void setup(Meter meter) {
+            counter = ((ExtendedLongCounterBuilder) meter.counterBuilder("counter")).build();
+          }
+
+          @Override
+          void record(long value) {
+            counter.add(value, httpServerSpanAttributes());
+          }
+        }),
+    /**
+     * Record HTTP metric attributes without advice. This baseline shows the lower bound if
+     * attribute filtering was done in instrumentation instead of the metrics SDK with advice. It's
+     * not quite fair though because instrumentation would have to separately allocate attributes
+     * for spans and metrics, whereas with advice, we can manage to only allocate span attributes
+     * and a lightweight metrics attributes view derived from span attributes.
+     */
+    NO_ADVICE_FILTERED_ATTRIBUTES(
+        new Instrument() {
+          private LongCounter counter;
+
+          @Override
+          void setup(Meter meter) {
+            counter = ((ExtendedLongCounterBuilder) meter.counterBuilder("counter")).build();
+          }
+
+          @Override
+          void record(long value) {
+            counter.add(value, httpServerMetricAttributes());
+          }
+        }),
+    /**
+     * Record cached HTTP span attributes without advice. This baseline helps isolate the CPU and
+     * memory allocation for recording vs. creating attributes.
+     */
+    NO_ADVICE_ALL_ATTRIBUTES_CACHED(
+        new Instrument() {
+          private LongCounter counter;
+
+          @Override
+          void setup(Meter meter) {
+            counter = ((ExtendedLongCounterBuilder) meter.counterBuilder("counter")).build();
+          }
+
+          @Override
+          void record(long value) {
+            counter.add(value, CACHED_HTTP_SERVER_SPAN_ATTRIBUTES);
+          }
+        }),
+    /**
+     * Record HTTP span attributes with advice filtering to HTTP metric attributes. This is meant to
+     * realistically demonstrate a typical HTTP server instrumentation scenario.
+     */
+    ADVICE_ALL_ATTRIBUTES(
+        new Instrument() {
+          private LongCounter counter;
+
+          @Override
+          void setup(Meter meter) {
+            counter =
+                ((ExtendedLongCounterBuilder) meter.counterBuilder("counter"))
+                    .setAttributesAdvice(httpServerMetricAttributeKeys)
+                    .build();
+          }
+
+          @Override
+          void record(long value) {
+            counter.add(value, httpServerSpanAttributes());
+          }
+        }),
+    /**
+     * Record HTTP metric attributes with advice filtering to HTTP metric attributes. This
+     * demonstrates the overhead of advice when no attributes are filtered.
+     */
+    ADVICE_FILTERED_ATTRIBUTES(
+        new Instrument() {
+          private LongCounter counter;
+
+          @Override
+          void setup(Meter meter) {
+            counter =
+                ((ExtendedLongCounterBuilder) meter.counterBuilder("counter"))
+                    .setAttributesAdvice(httpServerMetricAttributeKeys)
+                    .build();
+          }
+
+          @Override
+          void record(long value) {
+            counter.add(value, httpServerMetricAttributes());
+          }
+        }),
+    /**
+     * Record cached HTTP span attributes with advice filtering to HTTP metric attributes. This
+     * isolates the CPU and memory allocation for applying advice vs. creating attributes.
+     */
+    ADVICE_ALL_ATTRIBUTES_CACHED(
+        new Instrument() {
+          private LongCounter counter;
+
+          @Override
+          void setup(Meter meter) {
+            counter =
+                ((ExtendedLongCounterBuilder) meter.counterBuilder("counter"))
+                    .setAttributesAdvice(httpServerMetricAttributeKeys)
+                    .build();
+          }
+
+          @Override
+          void record(long value) {
+            counter.add(value, CACHED_HTTP_SERVER_SPAN_ATTRIBUTES);
+          }
+        });
+
+    private final Instrument instrument;
+
+    InstrumentParam(Instrument instrument) {
+      this.instrument = instrument;
+    }
+
+    Instrument instrument() {
+      return instrument;
+    }
+  }
+
+  private abstract static class Instrument {
+    abstract void setup(Meter meter);
+
+    abstract void record(long value);
+  }
+}

sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/internal/view/AdviceAttributesProcessor.java

@@ -7,7 +7,6 @@
 
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.common.Attributes;
-import io.opentelemetry.api.common.AttributesBuilder;
 import io.opentelemetry.context.Context;
 import java.util.HashSet;
 import java.util.List;
@@ -23,26 +22,7 @@ final class AdviceAttributesProcessor extends AttributesProcessor {
 
   @Override
   public Attributes process(Attributes incoming, Context context) {
-    // Exit early to avoid allocations if the incoming attributes do not have extra keys to be
-    // filtered
-    if (!hasExtraKeys(incoming)) {
-      return incoming;
-    }
-    AttributesBuilder builder = incoming.toBuilder();
-    builder.removeIf(key -> !attributeKeys.contains(key));
-    return builder.build();
-  }
-
-  /** Returns true if {@code attributes} has keys not contained in {@link #attributeKeys}. */
-  private boolean hasExtraKeys(Attributes attributes) {
-    boolean[] result = {false};
-    attributes.forEach(
-        (key, value) -> {
-          if (!result[0] && !attributeKeys.contains(key)) {
-            result[0] = true;
-          }
-        });
-    return result[0];
+    return FilteredAttributes.create(incoming, attributeKeys);
   }
 
   @Override