Datadog distributed tracing

Tags: ruby

NOTE: Newer versions of ddtrace have all this as an option (for sidekiq jobs)* See also https://github.com/datadog/dd-trace-rb/blob/master/docs/GettingStarted.md#sidekiq

This is for ddtrace v1.1

See also Distributed tracing docs

• Might need to use continue tracing when spawning threads or other weird scenarios like continuing tracing for background job processing.
• Need to use a TraceDigest object which is a wrapper for trace properties. If needed this can easily be serialized as JSON and later parsed to re-instantiate a TraceDigest object. Example…

# Cache the trace digest as JSON string
current_trace = Datadog::Tracing.active_trace
trace_digest_json = current_trace&.to_digest&.to_json

# Later re-instantiate a TraceDigest with parsed digest properties and continue trace
if trace_digest_json
  trace_digest = Datadog::Tracing::TraceDigest.new(**JSON.parse(trace_digest_json).symbolize_keys)

  Datadog::Tracing.trace('foo', resource: 'bar', continue_from: trace_digest) do
    # do stuff
  end
end