Convert MinRTT to milliseconds (#1129)

* Convert MinRTT to milliseconds
* Update distribution for python3 and gcloud sdk
* Update schema docs and notes for S2C fields published in nanoseconds

Author: stephen-soltesz

.travis.yml

@@ -5,7 +5,7 @@
 # The travis-ci.com configuration performs unit and integration tests, and code
 # coverage only.
 
-dist: bionic
+dist: jammy # 22.04
 language: go
 go:
  - 1.20

parser/ndt5_result.go

@@ -176,10 +176,10 @@ func (dp *NDT5ResultParser) prepareS2CRow(row *schema.NDT5ResultRowV2) {
 	// Since the s2c.MinRTT value is a lower resolution user-space estimate,
 	// use TCPInfo if present, and fall back to the low resolution MinRTT otherwise.
 	if s2c.TCPInfo != nil {
-		// TCPInfo.MinRTT is a uint32.
-		row.A.MinRTT = float64(s2c.TCPInfo.MinRTT) / 1000.0 / 1000.0
+		// TCPInfo.MinRTT is a uint32. Convert to milliseconds.
+		row.A.MinRTT = float64(s2c.TCPInfo.MinRTT) / 1000.0
 	} else {
-		// MinRTT is a time.Duration.
+		// s2c.MinRTT is a time.Duration. Convert back to milliseconds.
 		row.A.MinRTT = float64(s2c.MinRTT) / float64(time.Millisecond)
 	}
 	// NOTE: the TCPInfo structure was introduced in v0.18.0. Measurements

parser/ndt5_result_test.go

@@ -108,9 +108,9 @@ func TestNDT5ResultParser_ParseAndInsert(t *testing.T) {
 					download.Raw.S2C.UUID, download.A.UUID)
 			}
 			// Verify a.MinRTT when S2C.TCPInfo is present.
-			if tt.expectTCPInfo && download.A.MinRTT != float64(download.Raw.S2C.TCPInfo.MinRTT)/1000.0/1000.0 {
+			if tt.expectTCPInfo && download.A.MinRTT != float64(download.Raw.S2C.TCPInfo.MinRTT)/1000.0 {
 				t.Fatalf("A.MinRTT does not match Raw.S2C.TCPInfo.MinRTT; got %f, want %f",
-					download.A.MinRTT, float64(download.Raw.S2C.TCPInfo.MinRTT)/1000.0/1000.0)
+					download.A.MinRTT, float64(download.Raw.S2C.TCPInfo.MinRTT)/1000.0)
 			}
 			// Verify a.MinRTT when S2C.TCPInfo is not present.
 			if tt.expectMetadata && download.A.MinRTT != float64(download.Raw.S2C.MinRTT)/float64(time.Millisecond) {

schema/descriptions/NDT5ResultRowV2.yaml

@@ -16,7 +16,7 @@ a.MeanThroughputMbps:
     it is identified as "MeanThroughputMbps".
 a.MinRTT:
   Description: The minimum Round Trip Time observed during the measurement,
-    recorded in milliseconds.
+    recorded in milliseconds. Derived from TCPInfo.MinRTT after 2020-06-18.
 a.LossRate:
   Description: Loss rate from the lifetime of the connection.
 
@@ -100,15 +100,13 @@ S2C:
   Description: Metadata for Server-to-Client (download) measurements performed
     using the ndt5 protocol.
 S2C.MinRTT:
-  Description: The minimum RTT observed during the download measurement, recorded in milliseconds.
+  Description: The application measured minimum observed round trip time, recorded in nanoseconds.
 S2C.MaxRTT:
-  Description: The maximum sampled round trip time, recorded in milliseconds.
+  Description: The application measured maximum sampled round trip time, recorded in nanoseconds.
 S2C.SumRTT:
-  Description: The sum of all sampled round trip times, recorded in
-    milliseconds.
+  Description: The sum of all sampled round trip times, recorded in nanoseconds.
 S2C.CountRTT:
-  Description: The number of round trip time samples included in S2C.SumRTT,
-    reported in milliseconds.
+  Description: The number of round trip time samples included in S2C.SumRTT.
 S2C.ClientReportedMbps:
   Description: The download rate as calculated by the client, in megabits per
     second, or Mbit/s. Not all clients report this value.
@@ -254,7 +252,7 @@ TCPInfo.NotsentBytes:
     sent.
   Kernel: tcpi_notsent_bytes() in net/ipv4/tcp.c
 TCPInfo.MinRTT:
-  Description: Minimum Round Trip Time. From an older, pre-BBR algorithm.
+  Description: Minimum Round Trip Time. From an older, pre-BBR algorithm. Recorded in microseconds.
   Kernel: tcp_min_rtt in include/net/tcp.h
 TCPInfo.DataSegsIn:
   Description: Input segments carrying data (len>0).

schema/descriptions/NDT7ResultRow.yaml

@@ -57,7 +57,7 @@ BBRInfo.BW:
   Description: The maximum end-to-end bandwidth from the server to the client
     as measured by BBR.
 BBRInfo.MinRTT:
-  Description: The minimum round trip time as measured by BBR.
+  Description: The minimum round trip time as measured by BBR. Recorded in microseconds.
 BBRInfo.PacingGain:
   Description: Fixed point multiplier used to set the pacing rate from the
     maximum bandwidth.  The binary point varies by kernel version but the
@@ -207,7 +207,7 @@ TCPInfo.NotsentBytes:
     sent.
   Kernel: tcpi_notsent_bytes() in net/ipv4/tcp.c
 TCPInfo.MinRTT:
-  Description: Minimum Round Trip Time. From an older, pre-BBR algorithm.
+  Description: Minimum Round Trip Time. Recorded in microseconds.
   Kernel: tcp_min_rtt in include/net/tcp.h
 TCPInfo.DataSegsIn:
   Description: Input segments carrying data (len>0).