Ensure that span start <= end

Adds code to detect when a span's end time is less than its start time. This would be caught by a database constraint and prevent the insertion of the span. The new code will swap the start and end times to allow the span's insertion.

Author: jgpruitt

CHANGELOG.md

@@ -23,6 +23,7 @@ We use the following categories for changes:
 ### Fixed
 - Fix broken `promscale_packager` telemetry field for docker envs [#1077]
 - Fix compression of old chunks thus reducing storage requirements [#1081]
+- Fix spans with end < start. Start and end are swapped in this case. [#1096]
 
 ## [0.8.0] - 2022-01-18
 

pkg/pgmodel/ingestor/trace/writer.go

@@ -265,15 +265,23 @@ func (t *traceWriterImpl) InsertTraces(ctx context.Context, traces pdata.Traces)
 
 				eventTimeRange := getEventTimeRange(span.Events())
 
+				// postgresql timestamptz only has microsecond precision while time.Time has nanosecond precision
+				start := span.StartTimestamp().AsTime().Truncate(time.Microsecond)
+				end := span.EndTimestamp().AsTime().Truncate(time.Microsecond)
+				// make sure start <= end
+				if end.Before(start) {
+					start, end = end, start
+				}
+
 				spanBatch.Queue(
 					insertSpanSQL,
 					traceID,
 					spanID,
 					getTraceStateValue(span.TraceState()),
 					parentSpanID,
 					operationID,
-					span.StartTimestamp().AsTime(),
-					span.EndTimestamp().AsTime(),
+					start,
+					end,
 					string(jsonTags),
 					span.DroppedAttributesCount(),
 					eventTimeRange,