NestJS + Opentelemetry(샘플링)

import { TraceIdRatioBasedSampler } from '@opentelemetry/sdk-trace-node'; const samplePercentage = 0.1; const sdk = new NodeSDK({ // Other SDK configuration parameters go here sampler: new TraceIdRatioBasedSampler(samplePercentage), });

import { Context } from "@opentelemetry/api"; import { SpanProcessor, ReadableSpan, Span, } from "@opentelemetry/sdk-trace-node"; /** * Sampling span processor (including all error span and ratio of other spans) */ export class SamplingSpanProcessor implements SpanProcessor { constructor( private _spanProcessor: SpanProcessor, private _ratio: number ) {} /** * Forces to export all finished spans */ forceFlush(): Promise { return this._spanProcessor.forceFlush(); } onStart(span: Span, parentContext: Context): void { this._spanProcessor.onStart(span, parentContext); } shouldSample(traceId: string): boolean { let accumulation = 0; for (let idx = 0; idx < traceId.length; idx++) { accumulation += traceId.charCodeAt(idx); } const cmp = (accumulation % 100) / 100; return cmp < this._ratio; } /** * Called when a {@link ReadableSpan} is ended, if the `span.isRecording()` * returns true. * @param span the Span that just ended. */ onEnd(span: ReadableSpan): void { // Only process spans that have an error status if (span.status.code === 2) { // Status code 0 means "UNSET", 1 means "OK", and 2 means "ERROR" this._spanProcessor.onEnd(span); } else { if (this.shouldSample(span.spanContext().traceId)) { this._spanProcessor.onEnd(span); } } } /** * Shuts down the processor. Called when SDK is shut down. This is an * opportunity for processor to do any cleanup required. */ async shutdown(): Promise { return this._spanProcessor.shutdown(); } }

spanProcessors: [ new SamplingSpanProcessor( new BatchSpanProcessor(traceExporter), samplePercentage ), ],