diff --git a/dd-trace-api/src/main/java/datadog/trace/api/config/GeneralConfig.java b/dd-trace-api/src/main/java/datadog/trace/api/config/GeneralConfig.java
index c9963516f1a..79d3861d8ab 100644
--- a/dd-trace-api/src/main/java/datadog/trace/api/config/GeneralConfig.java
+++ b/dd-trace-api/src/main/java/datadog/trace/api/config/GeneralConfig.java
@@ -79,6 +79,7 @@ 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 AZURE_APP_SERVICES = "azure.app.services";
public static final String INTERNAL_EXIT_ON_FAILURE = "trace.internal.exit.on.failure";
diff --git a/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateEntry.java b/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateEntry.java
index f325ac4816b..b5e253331b7 100644
--- a/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateEntry.java
+++ b/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateEntry.java
@@ -1,6 +1,7 @@
package datadog.trace.common.metrics;
import datadog.metrics.api.Histogram;
+import datadog.trace.api.Config;
import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString;
import datadog.trace.core.monitor.HealthMetrics;
import datadog.trace.util.Hashtable;
@@ -33,36 +34,54 @@ final class AggregateEntry extends Hashtable.Entry {
private static final UTF8BytesString[] EMPTY_TAGS = new UTF8BytesString[0];
- // Sentinel substitution is disabled until per-component config is wired in a follow-up PR.
- // Tests that need sentinel mode should pass useBlockedSentinel=true explicitly.
- static final boolean LIMITS_ENABLED = false;
-
- // Per-field cardinality handlers. Limits live on MetricCardinalityLimits -- see that class for
- // per-field rationale.
+ // Per-field cardinality handlers. Limits are tunable via DD_TRACE_STATS_{field}_CARDINALITY_LIMIT
+ // (e.g. DD_TRACE_STATS_RESOURCE_CARDINALITY_LIMIT). Defaults live on MetricCardinalityLimits.
+ // Frozen at first class-load from Config.
static final PropertyCardinalityHandler RESOURCE_HANDLER =
- new PropertyCardinalityHandler("resource", MetricCardinalityLimits.RESOURCE, LIMITS_ENABLED);
+ new PropertyCardinalityHandler(
+ "resource",
+ Config.get().getTraceStatsCardinalityLimit("resource", MetricCardinalityLimits.RESOURCE));
static final PropertyCardinalityHandler SERVICE_HANDLER =
- new PropertyCardinalityHandler("service", MetricCardinalityLimits.SERVICE, LIMITS_ENABLED);
+ new PropertyCardinalityHandler(
+ "service",
+ Config.get().getTraceStatsCardinalityLimit("service", MetricCardinalityLimits.SERVICE));
static final PropertyCardinalityHandler OPERATION_HANDLER =
new PropertyCardinalityHandler(
- "operation", MetricCardinalityLimits.OPERATION, LIMITS_ENABLED);
+ "operation",
+ Config.get()
+ .getTraceStatsCardinalityLimit("operation", MetricCardinalityLimits.OPERATION));
static final PropertyCardinalityHandler SERVICE_SOURCE_HANDLER =
new PropertyCardinalityHandler(
- "service_source", MetricCardinalityLimits.SERVICE_SOURCE, LIMITS_ENABLED);
+ "service_source",
+ Config.get()
+ .getTraceStatsCardinalityLimit(
+ "service_source", MetricCardinalityLimits.SERVICE_SOURCE));
static final PropertyCardinalityHandler TYPE_HANDLER =
- new PropertyCardinalityHandler("type", MetricCardinalityLimits.TYPE, LIMITS_ENABLED);
+ new PropertyCardinalityHandler(
+ "type",
+ Config.get().getTraceStatsCardinalityLimit("type", MetricCardinalityLimits.TYPE));
static final PropertyCardinalityHandler SPAN_KIND_HANDLER =
new PropertyCardinalityHandler(
- "span_kind", MetricCardinalityLimits.SPAN_KIND, LIMITS_ENABLED);
+ "span_kind",
+ Config.get()
+ .getTraceStatsCardinalityLimit("span_kind", MetricCardinalityLimits.SPAN_KIND));
static final PropertyCardinalityHandler HTTP_METHOD_HANDLER =
new PropertyCardinalityHandler(
- "http_method", MetricCardinalityLimits.HTTP_METHOD, LIMITS_ENABLED);
+ "http_method",
+ Config.get()
+ .getTraceStatsCardinalityLimit("http_method", MetricCardinalityLimits.HTTP_METHOD));
static final PropertyCardinalityHandler HTTP_ENDPOINT_HANDLER =
new PropertyCardinalityHandler(
- "http_endpoint", MetricCardinalityLimits.HTTP_ENDPOINT, LIMITS_ENABLED);
+ "http_endpoint",
+ Config.get()
+ .getTraceStatsCardinalityLimit(
+ "http_endpoint", MetricCardinalityLimits.HTTP_ENDPOINT));
static final PropertyCardinalityHandler GRPC_STATUS_CODE_HANDLER =
new PropertyCardinalityHandler(
- "grpc_status_code", MetricCardinalityLimits.GRPC_STATUS_CODE, LIMITS_ENABLED);
+ "grpc_status_code",
+ Config.get()
+ .getTraceStatsCardinalityLimit(
+ "grpc_status_code", MetricCardinalityLimits.GRPC_STATUS_CODE));
// Single authoritative list used by resetCardinalityHandlers(). populateFrom() and hashOf() keep
// named access for readability and to avoid per-span iteration overhead; this array ensures the
diff --git a/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateTable.java b/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateTable.java
index fcd6c5fcdb4..6010fb18a5c 100644
--- a/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateTable.java
+++ b/dd-trace-core/src/main/java/datadog/trace/common/metrics/AggregateTable.java
@@ -83,10 +83,10 @@ AggregateEntry findOrInsert(SpanSnapshot snapshot) {
* {@code onStatsAggregateDropped}) rather than evicting an established one. Cap is sized to the
* steady-state working set, so eviction is rare in the common case.
*
- * How often this fires depends on {@link AggregateEntry#LIMITS_ENABLED}. With limits enabled,
- * over-cap values for a given field collapse into a shared {@code blocked_by_tracer} bucket, so
- * the table itself rarely reaches {@code maxAggregates}. With limits disabled (the default),
- * over-cap values flow to distinct buckets and {@code maxAggregates} becomes the load-bearing
+ *
With per-field cardinality limits enabled, over-cap values for a given field collapse into a
+ * shared {@code tracer_blocked_value} bucket, so the table itself rarely reaches {@code
+ * maxAggregates}. Without per-field limits, over-cap values flow to distinct buckets and {@code
+ * maxAggregates} becomes the load-bearing
* backstop -- the cursor-resumed scan was added specifically for this regime.
*/
private boolean evictOneStale() {
diff --git a/dd-trace-core/src/main/java/datadog/trace/common/metrics/MetricCardinalityLimits.java b/dd-trace-core/src/main/java/datadog/trace/common/metrics/MetricCardinalityLimits.java
index 58dcd3a70a1..1917f6add57 100644
--- a/dd-trace-core/src/main/java/datadog/trace/common/metrics/MetricCardinalityLimits.java
+++ b/dd-trace-core/src/main/java/datadog/trace/common/metrics/MetricCardinalityLimits.java
@@ -14,9 +14,10 @@ private MetricCardinalityLimits() {}
/**
* Distinct {@code resource.name} values per cycle. Highest-cardinality field by far: DB-query
- * obfuscations, HTTP route templates, custom resources. Typical service: 30-200 unique.
+ * obfuscations, HTTP route templates, custom resources. Typical service: 30-200 unique; 1024
+ * leaves headroom for high-cardinality SQL/HTTP workloads without risking premature collapse.
*/
- static final int RESOURCE = 256;
+ static final int RESOURCE = 1024;
/**
* Distinct {@code service.name} values per cycle. Local service plus downstream peer-service
diff --git a/dd-trace-core/src/main/java/datadog/trace/common/metrics/PeerTagSchema.java b/dd-trace-core/src/main/java/datadog/trace/common/metrics/PeerTagSchema.java
index e9eb7a6b823..5b9f66542cd 100644
--- a/dd-trace-core/src/main/java/datadog/trace/common/metrics/PeerTagSchema.java
+++ b/dd-trace-core/src/main/java/datadog/trace/common/metrics/PeerTagSchema.java
@@ -3,6 +3,7 @@
import static datadog.trace.api.DDTags.BASE_SERVICE;
import datadog.communication.ddagent.DDAgentFeaturesDiscovery;
+import datadog.trace.api.Config;
import datadog.trace.bootstrap.instrumentation.api.UTF8BytesString;
import datadog.trace.core.monitor.HealthMetrics;
import java.util.Set;
@@ -79,7 +80,10 @@ static PeerTagSchema of(Set names, String state) {
for (int i = 0; i < names.length; i++) {
this.handlers[i] =
new TagCardinalityHandler(
- names[i], MetricCardinalityLimits.PEER_TAG_VALUE, AggregateEntry.LIMITS_ENABLED);
+ names[i],
+ Config.get()
+ .getTraceStatsCardinalityLimit(
+ "peer_tag", MetricCardinalityLimits.PEER_TAG_VALUE));
}
}
diff --git a/internal-api/src/main/java/datadog/trace/api/Config.java b/internal-api/src/main/java/datadog/trace/api/Config.java
index b10bda7c683..74e77dd8e65 100644
--- a/internal-api/src/main/java/datadog/trace/api/Config.java
+++ b/internal-api/src/main/java/datadog/trace/api/Config.java
@@ -3863,6 +3863,17 @@ public int getTraceStatsInterval() {
return traceStatsInterval;
}
+ /**
+ * Returns the per-cycle cardinality limit for the named stats field, following the RFC naming
+ * pattern {@code DD_TRACE_STATS_{tagName}_CARDINALITY_LIMIT} (e.g. {@code
+ * DD_TRACE_STATS_RESOURCE_CARDINALITY_LIMIT}). The caller supplies the default from {@code
+ * MetricCardinalityLimits} so per-field rationale stays co-located with the defaults.
+ */
+ public int getTraceStatsCardinalityLimit(String tagName, int defaultLimit) {
+ return configProvider.getInteger(
+ "trace.stats." + tagName + ".cardinality.limit", defaultLimit);
+ }
+
public boolean isLogsInjectionEnabled() {
return logsInjectionEnabled;
}
diff --git a/metadata/supported-configurations.json b/metadata/supported-configurations.json
index ae081138b71..afe9bf20a78 100644
--- a/metadata/supported-configurations.json
+++ b/metadata/supported-configurations.json
@@ -10641,6 +10641,86 @@
"aliases": []
}
],
+ "DD_TRACE_STATS_RESOURCE_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "1024",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_SERVICE_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "32",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_OPERATION_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "64",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_SERVICE_SOURCE_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "16",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_TYPE_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "16",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_SPAN_KIND_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "8",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_HTTP_METHOD_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "16",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_HTTP_ENDPOINT_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "64",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_GRPC_STATUS_CODE_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "24",
+ "aliases": []
+ }
+ ],
+ "DD_TRACE_STATS_PEER_TAG_CARDINALITY_LIMIT": [
+ {
+ "version": "A",
+ "type": "integer",
+ "default": "512",
+ "aliases": []
+ }
+ ],
"DD_TRACE_STATUS404DECORATOR_ENABLED": [
{
"version": "A",