Package com.linkedin.venice.stats.metrics

Class AsyncMetricEntityStateTwoEnums<E1 extends Enum<E1> & VeniceDimensionInterface,E2 extends Enum<E2> & VeniceDimensionInterface>

java.lang.Object

com.linkedin.venice.stats.metrics.AsyncMetricEntityStateTwoEnums<E1,E2>

public class AsyncMetricEntityStateTwoEnums<E1 extends Enum<E1> & VeniceDimensionInterface,E2 extends Enum<E2> & VeniceDimensionInterface>
extends Object

Async state wrapper for a metric with two enum dimensions (MetricType.ASYNC_GAUGE or MetricType.ASYNC_DOUBLE_GAUGE).

Two-callback contract (enforces cardinality control)

This class registers exactly ONE OTel observable gauge per metric entity. The caller provides:

1. AsyncMetricResolvers.LiveStateResolverTwoEnums — maps an (e1, e2) pair to its backing state, or null when the pair is dormant. The null return is the liveness signal: the SDK never sees an attribute set for a dormant pair, so the cardinality cap is only charged for pairs that actually have data.
2. AsyncMetricResolvers.ValueResolverTwoEnums — reads the numeric value from the resolved state plus both enum values (useful when the value logic branches on the enums). Only invoked when AsyncMetricResolvers.LiveStateResolverTwoEnums.resolve(E1, E2) returned non-null.

Splitting the two phases forces the caller to think about liveness: there is no path from "pair" to "value" that skips the state resolution, so it is impossible to accidentally emit a dormant attribute set.

Attribute sets are precomputed once per pair at construction and cached. Per-collection cost is O(|E1| × |E2|) liveStateResolver calls plus one measurement.record(...) per emitted pair.

Method Summary

Modifier and Type	Method	Description
static <E1 extends Enum<E1> & VeniceDimensionInterface, E2 extends Enum<E2> & VeniceDimensionInterface, S> AsyncMetricEntityStateTwoEnums<E1,E2>	create(MetricEntity metricEntity, VeniceOpenTelemetryMetricsRepository otelRepository, Map<VeniceMetricsDimensions,String> baseDimensionsMap, Class<E1> enumTypeClass1, Class<E2> enumTypeClass2, AsyncMetricResolvers.LiveStateResolverTwoEnums<E1,E2,S> liveStateResolver, AsyncMetricResolvers.ValueResolverTwoEnums<S,E1,E2> valueResolver)	Creates a state wrapper and registers a single multi-emit observable gauge.
boolean	emitOpenTelemetryMetrics()
EnumMap<E1,EnumMap<E2,io.opentelemetry.api.common.Attributes>>	getAttributesByEnum()	Visible for testing — the cached attributes per (e1, e2), or null if OTel is disabled.
Object	getInstrument()	Visible for testing — the underlying SDK instrument handle, or null if OTel disabled.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

create

public static <E1 extends Enum<E1> & VeniceDimensionInterface,
E2 extends Enum<E2> & VeniceDimensionInterface,
S>
AsyncMetricEntityStateTwoEnums<E1,E2> create(MetricEntity metricEntity,
 VeniceOpenTelemetryMetricsRepository otelRepository,
 Map<VeniceMetricsDimensions,String> baseDimensionsMap,
 Class<E1> enumTypeClass1,
 Class<E2> enumTypeClass2,
 AsyncMetricResolvers.LiveStateResolverTwoEnums<E1,E2,S> liveStateResolver,
 AsyncMetricResolvers.ValueResolverTwoEnums<S,E1,E2> valueResolver)

Creates a state wrapper and registers a single multi-emit observable gauge. On every collection the SDK invokes the callback, which for each (e1, e2) pair:

• calls liveStateResolver.resolve(e1, e2) — if null, skips this pair for this cycle;
• otherwise calls valueResolver.extractValue(state, e1, e2) and emits a data point with the precomputed attributes.

Type Parameters:

S - the state type returned by liveStateResolver. Any reference type — the infra never inspects it beyond null-check.

emitOpenTelemetryMetrics

public boolean emitOpenTelemetryMetrics()

getAttributesByEnum

public EnumMap<E1,EnumMap<E2,io.opentelemetry.api.common.Attributes>> getAttributesByEnum()

Visible for testing — the cached attributes per (e1, e2), or null if OTel is disabled.

getInstrument

public Object getInstrument()

Visible for testing — the underlying SDK instrument handle, or null if OTel disabled.