From cc7c59af9f09932168bad4b3f94e3e09d336f6be Mon Sep 17 00:00:00 2001
From: "mergify[bot]" <37929162+mergify[bot]@users.noreply.github.com>
Date: Fri, 22 Dec 2023 21:14:01 -0800
Subject: [PATCH] v1.17: add metrics on throttled streams (backport of #34579)
 (#34582)

add metrics on throttled streams (#34579)

(cherry picked from commit 1a001751dd5631eb956eeed64c4ea07aa4cc41af)

Co-authored-by: Lijun Wang <83639177+lijunwangs@users.noreply.github.com>
---
 streamer/src/nonblocking/quic.rs | 1 +
 streamer/src/quic.rs             | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/streamer/src/nonblocking/quic.rs b/streamer/src/nonblocking/quic.rs
index 8f8adc506103ba..951ec6cb317fcd 100644
--- a/streamer/src/nonblocking/quic.rs
+++ b/streamer/src/nonblocking/quic.rs
@@ -742,6 +742,7 @@ async fn handle_connection(
                     if reset_throttling_params_if_needed(&mut last_throttling_instant) {
                         streams_in_current_interval = 0;
                     } else if streams_in_current_interval >= max_streams_per_100ms {
+                        stats.throttled_streams.fetch_add(1, Ordering::Relaxed);
                         let _ = stream.stop(VarInt::from_u32(STREAM_STOP_CODE_THROTTLING));
                         continue;
                     }
diff --git a/streamer/src/quic.rs b/streamer/src/quic.rs
index fee0db110f11ec..8b2b4f9d852cac 100644
--- a/streamer/src/quic.rs
+++ b/streamer/src/quic.rs
@@ -156,6 +156,7 @@ pub struct StreamStats {
     pub(crate) connection_setup_error_locally_closed: AtomicUsize,
     pub(crate) connection_removed: AtomicUsize,
     pub(crate) connection_remove_failed: AtomicUsize,
+    pub(crate) throttled_streams: AtomicUsize,
 }
 
 impl StreamStats {
@@ -386,6 +387,11 @@ impl StreamStats {
                 self.total_stream_read_timeouts.swap(0, Ordering::Relaxed),
                 i64
             ),
+            (
+                "throttled_streams",
+                self.throttled_streams.swap(0, Ordering::Relaxed),
+                i64
+            ),
         );
     }
 }