Allow gRPC error code config similar to HTTP

The dd.http.client.error.statuses config allows you to set a range of status codes that won’t be reported as errors and, by default, 4xx errors aren’t reported. A similar config for gRPC so codes like Canceled, NotFound, etc. don’t report as errors should be generally helpful. dd-trace-go added support in March, '19, https://github.com/DataDog/dd-trace-go/pull/414.

[ghost]

The Scala code we ended up with,

class StatusInterceptor() extends TraceInterceptor {
  private val nonErrors = Set(CANCELLED, INVALID_ARGUMENT, NOT_FOUND).map(_.getCode.name)

  override def onTraceComplete(trace: util.Collection[_ <: MutableSpan]): util.Collection[_ <: MutableSpan] =
    trace.asScala
      .map(s =>
        if (s.isError && s.getTags.asScala
              .exists(t => t._1 == "status.code" && nonErrors.contains(t._2.toString)))
          s.setError(false)
        else s
      )
      .asJavaCollection

  override def priority(): Int = 10
}

[ghost]

Another response,

After submitting your feature request to the Engineering team they provided a way you accomplish this in the meantime. You could attempt setting up a Trace Interceptor with Mutable Span changing this to error or not an error with some kind of if statement.