Hello. I'm working on sending traces from a Nextjs app, and if I use the console exporter, I can see that there are traces being created. When I then switch to the OTLPTraceExporter, I'm getting the following error in my logs:

{
  "stack": "Error: connect ECONNREFUSED 127.0.0.1:4318\n    at TCPConnectWrap.afterConnect [as oncomplete] (node:net:1494:16)\n    at TCPConnectWrap.callbackTrampoline (node:internal/async_hooks:130:17)",
  "message": "connect ECONNREFUSED 127.0.0.1:4318",
  "errno": "-61",
  "code": "ECONNREFUSED",
  "syscall": "connect",
  "address": "127.0.0.1",
  "port": "4318",
  "name": "Error"
}

My instrumentation file: (Note access token has been redacted)

"use strict";

import { NodeSDK } from "@opentelemetry/sdk-node";
import { OTLPTraceExporter } from "@opentelemetry/exporter-trace-otlp-http";
import { Resource } from "@opentelemetry/resources";
import { SEMRESATTRS_SERVICE_NAME } from "@opentelemetry/semantic-conventions";
import { SimpleSpanProcessor } from "@opentelemetry/sdk-trace-node";
import { getNodeAutoInstrumentations } from "@opentelemetry/auto-instrumentations-node";
import { diag, DiagConsoleLogger, DiagLogLevel } from "@opentelemetry/api";

diag.setLogger(new DiagConsoleLogger(), <http://DiagLogLevel.INFO|DiagLogLevel.INFO>);

// configure the SDK to export telemetry data to the console
// enable all auto-instrumentations from the meta package
const exporterOptions = {
  url: "<https://ingest.eu.signoz.cloud:443/v1/traces>", // use your own data region or use localhost:8080 for self-hosted
  headers: { "signoz-access-token": "your-access-token" }, // Use if you are using SigNoz Cloud
};
const traceExporter = new OTLPTraceExporter(exporterOptions);
const sdk = new NodeSDK({
  resource: new Resource({
    [SEMRESATTRS_SERVICE_NAME]: `LEO-${process.env.APP_ENV}`,
  }),
  serviceName: `LEO-${process.env.APP_ENV}`,
  traceExporter,
  instrumentations: [getNodeAutoInstrumentations()],
  spanProcessors: [new SimpleSpanProcessor(new OTLPTraceExporter())],
});

// initialize the SDK and register with the OpenTelemetry API
// this enables the API to record telemetry
sdk.start();

// gracefully shut down the SDK on process exit
process.on("SIGTERM", () => {
  sdk
    .shutdown()
    .then(() => console.log("Tracing terminated"))
    .catch((error) => console.log("Error terminating tracing", error))
    .finally(() => process.exit(0));
});

If you haven't figured it out already, you should pass the

traceExporter

instead of creating a new one in

spanProcessors: [new SimpleSpanProcessor(new OTLPTraceExporter())]

. As you can see from the error logs, it is trying to send data to

127.0.0.1:4318

. This happens because the URL is not provided in ``new OTLPTraceExporter())`` so it uses the localhost.

Thank you for your response, and I will keep the intercom option in my back pocket. 🙂