Timestamps in shared spans
The following document is archived because reporting Zipkin v1 spans is a deprecated practice
Span.timestamp is problematic when misreported, or never reported. This issue will track known active zipkin libraries towards effective timestamp practice.
From http://zipkin.io/pages/instrumenting.html, the simplest logic for v1 format is:
unless (logging "sr" in an shared span) {
set Span.timestamp and duration (both in microseconds)
}
When a server joins a span from incoming headers, it is sharing the span with the client (who generated the headers). In that case, the server shouldn't set Span.timestamp or duration since its view of the span is later and shorter than the client.
Otherwise, you should set timestamp and duration on finished spans. That makes sure indexing and duration queries work best.
Note v2 format includes a shared flag which is used to help with this problem in v2 format, you always set timestamp and duration.
Here are the status options for Span.timestamp/duration:
- unsupported: the library never sets Span.timestamp/duration
- always: the library sets Span.timestamp/duration even when it shouldn't
- supported: the library sets Span.timestamp/duration only when it should
This is a list of zipkin libraries and their status in supporting Span.timestamp/duration
| library | version | status | notes |
|---|---|---|---|
| zipkin-js | 0.4+ | supported | |
| py_zipkin | 0.5+ | supported | |
| brave | 3.13+ | supported | |
| spring-cloud-sleuth | 1.0.11+ | supported | |
| finagle | versions supporting zipkin-finagle | supported | At the current time, zipkin-finagle must be used in order to report timestamps properly |
| zipkin-ruby | 0.12+ | supported | |
| ZipkinTracerModule | |||
| zipkin-go-opentracing | 0.2.1+ | supported | |
| zipkin4net | 0.3+ | supported | |
| akka-tracing | |||
| wingtips | |||
| jaeger |