tor-browser

commit 2661076a13cbc70e34f4886c840f9664f5891f61
parent b2bada9642675e69b7b8c4dca8d1c472c9d73696
Author: Oskar Mansfeld <git@omansfeld.net>
Date:   Mon,  5 Jan 2026 17:39:22 +0000

Bug 2004031 - Add labeled counter for congestion event reason. r=mxinden

Counting how many events are triggered by loss vs. ecn-ce marking.

Differential Revision: https://phabricator.services.mozilla.com/D275452

Diffstat:
M
netwerk/metrics.yaml
 | 
18
++++++++++++++++++
M
netwerk/socket/neqo_glue/src/lib.rs
 | 
20
++++++++++++++++++++

2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/netwerk/metrics.yaml b/netwerk/metrics.yaml
@@ -1131,6 +1131,24 @@ networking:
       - exited
       - not_exited
 
+  http_3_congestion_event_reason:
+    type: labeled_counter
+    description: >
+      The type of signal that caused a congestion event in Firefox's QUIC stack.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=2004031
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=2004031
+    data_sensitivity:
+      - technical
+    notification_emails:
+      - necko@mozilla.com
+      - omansfeld@mozilla.com
+    expires: 157
+    labels:
+      - loss
+      - ecn-ce
+
   http_3_connection_close_reason:
     type: labeled_counter
     description: >
diff --git a/netwerk/socket/neqo_glue/src/lib.rs b/netwerk/socket/neqo_glue/src/lib.rs
@@ -707,6 +707,26 @@ impl NeqoHttp3Conn {
                 debug_assert!(false, "{msg}");
             }
         }
+
+        // Collect congestion event reason metric
+        if let Ok(ce_loss) = i32::try_from(stats.cc.congestion_events[CongestionEvent::Loss]) {
+            glean::http_3_congestion_event_reason
+                .get("loss")
+                .add(ce_loss);
+        } else {
+            let msg = "Failed to convert to i32 for use with glean";
+            qwarn!("{msg}");
+            debug_assert!(false, "{msg}");
+        }
+        if let Ok(ce_ecn) = i32::try_from(stats.cc.congestion_events[CongestionEvent::Ecn]) {
+            glean::http_3_congestion_event_reason
+                .get("ecn-ce")
+                .add(ce_ecn);
+        } else {
+            let msg = "Failed to convert to i32 for use with glean";
+            qwarn!("{msg}");
+            debug_assert!(false, "{msg}");
+        }
     }
 
     fn increment_would_block_rx(&mut self) {