Activate an OpenTelemetry span for an R scope

Activates the span for the caller (or other) frame.

Usually you need this function for spans created with start_span(), which does not activate the new span. Usually you don't need it for spans created with start_local_active_span(), because it activates the new span automatically.

local_active_span(span, end_on_exit = FALSE, activation_scope = parent.frame())

Arguments

span

The OpenTelemetry span to activate.

end_on_exit

Whether to end the span when exiting the activation scope.

activation_scope

The scope to activate the span for, defaults to the caller frame.

Value

Nothing.

Details

When the frame ends, the span is deactivated and the previously active span will be active again, if there was any.

It is possible to activate the same span for multiple R frames.

See also

Other OpenTelemetry trace API: Zero Code Instrumentation, end_span(), is_tracing_enabled(), start_local_active_span(), start_span(), tracing-constants, with_active_span()

Other tracing for concurrent code: with_active_span()

Examples

fun <- function() {
  # start span, do not activate
  spn <- otel::start_span("myfun")
  # do not leak resources
  on.exit(otel::end_span(spn), add = TRUE)
  myfun <- function() {
     # activate span for this function
     otel::local_active_span(spn)
     # create child span
     spn2 <- otel::start_local_active_span("myfun/2")
  }

  myfun2 <- function() {
    # activate span for this function
    otel::local_active_span(spn)
    # create child span
    spn3 <- otel::start_local_active_span("myfun/3")
  }
  myfun()
  myfun2()
  end_span(spn)
}
fun()