comments

opentelemetry/proto/metrics/v1/metrics.proto

@@ -52,18 +52,22 @@ message RawValue {
   // alongside the original measurement. Only labels that were dropped by the aggregator should be included
   repeated opentelemetry.proto.common.v1.StringKeyValue labels = 1;
 
-  // Exact time that the measurement was recorded
+  // time_unix_nano is the exact time when this RawValue was recorded
+  //
+  // Value is UNIX Epoch time in nanoseconds since 00:00:00 UTC on 1 January 1970.
   fixed64 time_unix_nano = 2;
 
   // Numerical value of the measurement that was recorded. Only one of these 
   // two fields is used for the data, based on MetricDescriptor.measurement_value_type
   double double_value = 3;
   int64 int64_value = 4;
 
-  // (Optional) Span ID of the current trace
+  // (Optional) Span ID of the current trace.
+  // span_id may be missing if the measurement is not recorded inside a trace or if the trace is not sampled.
   bytes span_id = 5;
 
-  // (Optional) Trace ID of the current trace
+  // (Optional) Trace ID of the current trace.
+  // trace_id may be missing if the measurement is not recorded inside a trace or if the trace is not sampled.
   bytes trace_id = 6;
 
   // (Optional) When sample_count is non-zero, this exemplar has been chosen in a statistically