Logs translation when SpanTranslator is at FINE/DEBUG level

[codefromthecrypt]

We've had a number of support issues around translation. This adds debug
logging which can help determine the cause of failures.

2018-04-09 13:51:19.279 DEBUG [/] 7295 --- [   XNIO-2 I/O-2] z.t.stackdriver.SpanTranslator           : >> translating zipkin span: {"traceId":"e7d33ab8fe95b3cb","id":"e7d33ab8fe95b3cb","kind":"SERVER","name":"get /","timestamp":1523253078006004,"duration":158196,"localEndpoint":{"serviceName":"frontend","ipv4":"192.168.1.113"},"remoteEndpoint":{"ipv6":"::1","port":60162},"tags":{"http.method":"GET","http.path":"/","mvc.controller.class":"Frontend","mvc.controller.method":"callBackend"}}
2018-04-09 13:51:19.281 DEBUG [/] 7295 --- [   XNIO-2 I/O-2] z.t.stackdriver.SpanTranslator           : << translated to stackdriver span: span_id: 16704760009066918859
kind: RPC_SERVER
name: "get /"
start_time {
  seconds: 1523253078
  nanos: 6004000
}
end_time {
  seconds: 1523253078
  nanos: 164200000
}
labels {
  key: "/http/method"
  value: "GET"
}
labels {
  key: "zipkin.io/http.path"
  value: "/"
}
labels {
  key: "zipkin.io/mvc.controller.class"
  value: "Frontend"
}
labels {
  key: "zipkin.io/mvc.controller.method"
  value: "callBackend"
}
labels {
  key: "zipkin.io/endpoint.ipv4"
  value: "192.168.1.113"
}
labels {
  key: "/component"
  value: "frontend"
}
labels {
  key: "/agent"
  value: "zipkin-java"
}

[codefromthecrypt]

@jsw does this look helpful?

[jsw]

@adriancole Thanks! A couple other ideas that may help

• More details than Cannot decode spans when returning 400.
• Sample JSON. The JSON generated by swagger has invalid ids. Took me a while to catch that and sort it out. https://zipkin.io/zipkin-api/#/default/post_spans

[codefromthecrypt]

Thanks for the tips. Should we icebox this change? Sounds like it wasn't your issue (translation wasn't the problem)

…

- More details than Cannot decode spans when returning 400. openzipkin/zipkin#1987 - Sample JSON. The JSON generated by swagger has invalid ids. Took me a while to catch that and sort it out. https://zipkin.io/zipkin-api/# /default/post_spans openzipkin/zipkin-api#46

[jsw]

No strong opinion and not urgent. I imagine it might be useful at some point to troubleshoot how zipkin spans are translated to Stackdriver spans. Haven't gotten to the point where I am applying that level of detail to the data I am sending. Documentation or a pointer to code that shows the mapping would be helpful.

[codefromthecrypt]

cutting 0.3.2