tracing-datamodel-sketch.txt

type Trace {
  repeated Span spans
}

type Span {
  required string name
  required int startTime
  required int endTime
  
  required SpanContext spanContext
  optional Link link   // should links be repeated?   census: repeated links, only one "reference"
                                                              "links" to spans from other traces are allowed
                                                              "reference" only from the same trace
  
  repeated AnyInfo infos  // non-timed stuff
  repeated Event events // timed stuff
}

type Link {
  required LinkType type // childof, followsfrom      TODO: other types of links (e.g. to other traces?)
  SpanContext spanParent
}

type Event {
  required int timestamp
  repeated Map<string, AnyEventInfo> infos   // bogdan: should this necessarily be a map?
}

type LogEventInfo : AnyEventInfo {
  either {
    string stringValue
	int64 intValue
	bool boolValue
  }
}

// uniquely identifies a span
type SpanContext {
  required int UUID
  
}

type HttpClientInfo : AnyInfo {
  required string url
  required string httpmethod
}
type DbClientInfo : AnyInfo {
  required string statement
  required string ...
}