Browser tracing without Metrics

[jjhuff]

Please answer these questions before submitting a bug report.

What version of OpenTelemetry are you using?

1.3.0/0.29.1

Please provide the code you used to setup the OpenTelemetry SDK

  const exporter = new OTLPTraceExporter({url: endpoint, });
  const provider = new WebTracerProvider({
    resource: new Resource({
      [SemanticResourceAttributes.SERVICE_NAME]: 'browser',
    }),
  });
  processor = new SpanAttributesProcessor();
  provider.addSpanProcessor(new BatchSpanProcessor(exporter));
  provider.register({
    contextManager: new ZoneContextManager(),
  });

What did you expect to see?/What did you see instead?

OTLPTraceExporter ends up pulling sdk-metrics-base into the bundle -- even though I'm not using metrics.
Ends up adding an extra 50KB in my bundle.

[legendecas]

The problem here is that @opentelemetry/otlp-transformer depends on @opentelemetry/sdk-metrics-base. We have efforts on this, like #2973. However, with tree-shaking, it is supposed to add no additional bundle size if the metrics part is not used at all.

[jjhuff]

However, with tree-shaking, it is supposed to add no additional bundle size if the metrics part is not used at all.

I think the problem comes when otlp-transformer does this:

export { createExportTraceServiceRequest } from './trace';
export { createExportMetricsServiceRequest } from './metrics';

without sideEffects being set, bundlers like WebPack will be forced to include the import from ./metrics. Alternatively, I suppose, consumers of this package could import directly from /trace or /metrics as needed.

[pichlermarc]

This is related to #2855 it seems. We agreed in the last SIG meeting to correctly set sideEffects to resolve this. However, we currently do not have anyone who is actively working on this, so help would be greatly appreciated. 🙂

[dyladan]

Removing the bug label since this is not really a bug, but a requested enhancement.

[dyladan]

I am going to close this as it is covered by #2855. Please put your +1 there