Per-component / tag cardinality limits in client-side stats

communication/src/main/java/datadog/communication/ddagent/DDAgentFeaturesDiscovery.java

@@ -138,7 +138,8 @@ protected long getFeaturesDiscoveryMinDelayMillis() {
 
   private synchronized void discoverIfOutdated(final long maxElapsedMs) {
     final long now = System.currentTimeMillis();
-    final long elapsed = now - discoveryState.lastTimeDiscovered;
+    final State previous = discoveryState;
+    final long elapsed = now - previous.lastTimeDiscovered;
     if (elapsed > maxElapsedMs) {
       final State newState = new State();
       doDiscovery(newState);

dd-trace-api/src/main/java/datadog/trace/api/config/GeneralConfig.java

@@ -76,6 +76,8 @@ public final class GeneralConfig {
   public static final String TRACER_METRICS_MAX_PENDING = "trace.tracer.metrics.max.pending";
   public static final String TRACER_METRICS_IGNORED_RESOURCES =
       "trace.tracer.metrics.ignored.resources";
+  public static final String TRACE_STATS_CARDINALITY_LIMITS_ENABLED =
+      "trace.stats.cardinality.limits.enabled";
 
   public static final String AZURE_APP_SERVICES = "azure.app.services";
   public static final String INTERNAL_EXIT_ON_FAILURE = "trace.internal.exit.on.failure";

dd-trace-core/src/jmh/java/datadog/trace/common/metrics/AdversarialMetricsBenchmark.java

@@ -60,7 +60,7 @@
 @Fork(value = 1)
 public class AdversarialMetricsBenchmark {
 
-  private ConflatingMetricsAggregator aggregator;
+  private ClientStatsAggregator aggregator;
   private CountingHealthMetrics health;
 
   @State(Scope.Thread)
@@ -72,13 +72,13 @@ public static class ThreadState {
   public void setup() {
     this.health = new CountingHealthMetrics();
     this.aggregator =
-        new ConflatingMetricsAggregator(
+        new ClientStatsAggregator(
             new WellKnownTags("", "", "", "", "", ""),
             Collections.emptySet(),
-            new ConflatingMetricsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
+            new ClientStatsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
                 Collections.singleton("peer.hostname"), Collections.emptySet()),
             this.health,
-            new ConflatingMetricsAggregatorBenchmark.NullSink(),
+            new ClientStatsAggregatorBenchmark.NullSink(),
             2048,
             2048,
             false);

dd-trace-core/src/jmh/java/datadog/trace/common/metrics/ConflatingMetricsAggregatorBenchmark.java → dd-trace-core/src/jmh/java/datadog/trace/common/metrics/ClientStatsAggregatorBenchmark.java

@@ -34,12 +34,12 @@
 @BenchmarkMode(Mode.AverageTime)
 @OutputTimeUnit(MICROSECONDS)
 @Fork(value = 1)
-public class ConflatingMetricsAggregatorBenchmark {
+public class ClientStatsAggregatorBenchmark {
   private final DDAgentFeaturesDiscovery featuresDiscovery =
       new FixedAgentFeaturesDiscovery(
           Collections.singleton("peer.hostname"), Collections.emptySet());
-  private final ConflatingMetricsAggregator aggregator =
-      new ConflatingMetricsAggregator(
+  private final ClientStatsAggregator aggregator =
+      new ClientStatsAggregator(
           new WellKnownTags("", "", "", "", "", ""),
           Collections.emptySet(),
           featuresDiscovery,

dd-trace-core/src/jmh/java/datadog/trace/common/metrics/ConflatingMetricsAggregatorDDSpanBenchmark.java → dd-trace-core/src/jmh/java/datadog/trace/common/metrics/ClientStatsAggregatorDDSpanBenchmark.java

@@ -28,8 +28,8 @@
 import org.openjdk.jmh.infra.Blackhole;
 
 /**
- * Parallels {@link ConflatingMetricsAggregatorBenchmark} but uses real {@link DDSpan} instances
- * instead of the lightweight {@code SimpleSpan} mock, so the JIT exercises the production {@link
+ * Parallels {@link ClientStatsAggregatorBenchmark} but uses real {@link DDSpan} instances instead
+ * of the lightweight {@code SimpleSpan} mock, so the JIT exercises the production {@link
  * CoreSpan#isKind} path (cached span.kind ordinal + bit-test) rather than the groovy mock's
  * dispatch.
  *
@@ -50,21 +50,21 @@
 @BenchmarkMode(Mode.AverageTime)
 @OutputTimeUnit(MICROSECONDS)
 @Fork(value = 1)
-public class ConflatingMetricsAggregatorDDSpanBenchmark {
+public class ClientStatsAggregatorDDSpanBenchmark {
 
   private static final CoreTracer TRACER =
       CoreTracer.builder().writer(new NoopWriter()).strictTraceWrites(false).build();
 
   private final DDAgentFeaturesDiscovery featuresDiscovery =
-      new ConflatingMetricsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
+      new ClientStatsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
           Collections.singleton("peer.hostname"), Collections.emptySet());
-  private final ConflatingMetricsAggregator aggregator =
-      new ConflatingMetricsAggregator(
+  private final ClientStatsAggregator aggregator =
+      new ClientStatsAggregator(
           new WellKnownTags("", "", "", "", "", ""),
           Collections.emptySet(),
           featuresDiscovery,
           HealthMetrics.NO_OP,
-          new ConflatingMetricsAggregatorBenchmark.NullSink(),
+          new ClientStatsAggregatorBenchmark.NullSink(),
           2048,
           2048,
           false);

dd-trace-core/src/jmh/java/datadog/trace/common/metrics/HighCardinalityPeerMetricsBenchmark.java

@@ -50,7 +50,7 @@
 @Fork(value = 1)
 public class HighCardinalityPeerMetricsBenchmark {
 
-  private ConflatingMetricsAggregator aggregator;
+  private ClientStatsAggregator aggregator;
   private CountingHealthMetrics health;
 
   @State(Scope.Thread)
@@ -62,13 +62,13 @@ public static class ThreadState {
   public void setup() {
     this.health = new CountingHealthMetrics();
     this.aggregator =
-        new ConflatingMetricsAggregator(
+        new ClientStatsAggregator(
             new WellKnownTags("", "", "", "", "", ""),
             Collections.emptySet(),
-            new ConflatingMetricsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
+            new ClientStatsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
                 Collections.singleton("peer.hostname"), Collections.emptySet()),
             this.health,
-            new ConflatingMetricsAggregatorBenchmark.NullSink(),
+            new ClientStatsAggregatorBenchmark.NullSink(),
             2048,
             2048,
             false);

dd-trace-core/src/jmh/java/datadog/trace/common/metrics/HighCardinalityResourceMetricsBenchmark.java

@@ -46,7 +46,7 @@
 @Fork(value = 1)
 public class HighCardinalityResourceMetricsBenchmark {
 
-  private ConflatingMetricsAggregator aggregator;
+  private ClientStatsAggregator aggregator;
   private CountingHealthMetrics health;
 
   @State(Scope.Thread)
@@ -58,13 +58,13 @@ public static class ThreadState {
   public void setup() {
     this.health = new CountingHealthMetrics();
     this.aggregator =
-        new ConflatingMetricsAggregator(
+        new ClientStatsAggregator(
             new WellKnownTags("", "", "", "", "", ""),
             Collections.emptySet(),
-            new ConflatingMetricsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
+            new ClientStatsAggregatorBenchmark.FixedAgentFeaturesDiscovery(
                 Collections.singleton("peer.hostname"), Collections.emptySet()),
             this.health,
-            new ConflatingMetricsAggregatorBenchmark.NullSink(),
+            new ClientStatsAggregatorBenchmark.NullSink(),
             2048,
             2048,
             false);