How to Exclude `OPTIONS` Requests from Traces?

[BridgeAR]

Discussed in https://github.com/DataDog/dd-trace-js/discussions/3965

^{Originally posted by Sangdol January 15, 2024} Our Express server receives many OPTIONS requests due to CORS. These OPTIONS traces are not very informative, and I'd like to exclude them. However, I haven't found a way to do so.

• According to the express plugin document, there appears to be no way to exclude requests based on an HTTP method.
• I attempted to exclude them using MANUAL_DROP as shown below, but it was ineffective because it added the tag to a new child span instead of the root span.

export const excludeOptionsRequests = async (
  req: Request,
  res: Response,
  next: NextFunction
) => {
  const span = tracer.scope().active();
  if (req?.method === "OPTIONS") {
    span?.setTag(MANUAL_DROP, true);
  }
  next();
};

Can I add the MANUAL_DROP tag to the root span express.request? Or, is there any other way to exclude OPTIONS requests from traces?

[SenneDirkx]

I would also like to know if this is possible, but for the fastify plugin.

[jbaute]

Looks like you can set up sampling in Datadog to drop the OPTIONS traces.

https://docs.datadoghq.com/tracing/guide/ignoring_apm_resources/?tab=datadogyaml