v25.11.24

changelog.md

@@ -1,5 +1,55 @@
 # Changelog
 
+## 2026-03-17 - 25.11.24 - fix(rustproxy-http)
+improve async static file serving, websocket handshake buffering, and shared metric metadata handling
+
+- convert static file serving to async filesystem operations and await directory/file checks
+- preserve and forward bytes read past the WebSocket handshake header terminator to avoid dropping buffered upstream data
+- reuse Arc<str> values for route and source identifiers across counting bodies and metric reporting
+- standardize backend key propagation across H1/H2 forwarding, retry, and fallback paths for consistent logging and metrics
+
+## 2026-03-17 - 25.11.23 - fix(rustproxy-http,rustproxy-metrics)
+reduce per-frame metrics overhead by batching body byte accounting
+
+- Buffer HTTP body byte counts and flush them every 64 KB, at end of stream, and on drop to keep totals accurate while preserving throughput sampling.
+- Skip zero-value counter updates in metrics collection to avoid unnecessary atomic and DashMap operations for the unused direction.
+
+## 2026-03-17 - 25.11.22 - fix(rustproxy-http)
+reuse healthy HTTP/2 upstream connections after requests with bodies
+
+- Registers successful HTTP/2 connections in the pool regardless of whether the proxied request included a body
+- Continues to avoid pooling upstream connections that returned 502 Bad Gateway responses
+
+## 2026-03-17 - 25.11.21 - fix(rustproxy-http)
+reuse pooled HTTP/2 connections for requests with and without bodies
+
+- remove the bodyless-request restriction from HTTP/2 pool checkout
+- always return successful HTTP/2 senders to the connection pool after requests
+
+## 2026-03-17 - 25.11.20 - fix(rustproxy-http)
+avoid downgrading cached backend protocol on H2 stream errors
+
+- Treat HTTP/2 stream-level failures as retryable request errors instead of evidence that the backend only supports HTTP/1.1
+- Keep protocol cache entries unchanged after successful H2 handshakes so future requests continue using HTTP/2
+- Lower log severity for this fallback path from warning to debug while still recording backend H2 failure metrics
+
+## 2026-03-16 - 25.11.19 - fix(rustproxy-http)
+avoid reusing pooled HTTP/2 connections for requests with bodies to prevent upload flow-control stalls
+
+- Limit HTTP/2 pool checkout to bodyless requests such as GET, HEAD, and DELETE
+- Skip re-registering HTTP/2 connections in the pool after requests that send a body
+- Prevent stalled uploads caused by depleted connection-level flow control windows on reused HTTP/2 connections
+
+## 2026-03-16 - 25.11.18 - fix(repo)
+no changes to commit
+
+
+## 2026-03-16 - 25.11.17 - fix(rustproxy-http)
+prevent stale HTTP/2 connection drivers from evicting newer pooled connections
+
+- add generation IDs to pooled HTTP/2 senders so pool removal only affects the matching connection
+- update HTTP/2 proxy and retry paths to register generation-tagged connections and skip eviction before registration completes
+
 ## 2026-03-16 - 25.11.16 - fix(repo)
 no changes to commit
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@push.rocks/smartproxy",
-  "version": "25.11.16",
+  "version": "25.11.24",
   "private": false,
   "description": "A powerful proxy package with unified route-based configuration for high traffic management. Features include SSL/TLS support, flexible routing patterns, WebSocket handling, advanced security options, and automatic ACME certificate management.",
   "main": "dist_ts/index.js",

rust/crates/rustproxy-http/src/connection_pool.rs

@@ -4,13 +4,13 @@
 //! HTTP/2 connections are multiplexed (clone the sender for each request).
 
 use std::sync::Arc;
+use std::sync::atomic::{AtomicU64, Ordering};
 use std::time::{Duration, Instant};
 
 use bytes::Bytes;
 use dashmap::DashMap;
 use http_body_util::combinators::BoxBody;
 use hyper::client::conn::{http1, http2};
-// No per-request logging in the pool — only log on actual failures (in proxy_service.rs)
 
 /// Maximum idle connections per backend key.
 const MAX_IDLE_PER_KEY: usize = 16;
@@ -38,10 +38,13 @@ struct IdleH1 {
     idle_since: Instant,
 }
 
-/// A pooled HTTP/2 sender (multiplexed, Clone-able).
+/// A pooled HTTP/2 sender (multiplexed, Clone-able) with a generation tag.
 struct PooledH2 {
     sender: http2::SendRequest<BoxBody<Bytes, hyper::Error>>,
     created_at: Instant,
+    /// Unique generation ID. Connection drivers use this to only remove their OWN
+    /// entry, preventing phantom eviction when multiple connections share the same key.
+    generation: u64,
 }
 
 /// Backend connection pool.
@@ -50,6 +53,8 @@ pub struct ConnectionPool {
     h1_pool: Arc<DashMap<PoolKey, Vec<IdleH1>>>,
     /// HTTP/2 multiplexed connections indexed by backend key.
     h2_pool: Arc<DashMap<PoolKey, PooledH2>>,
+    /// Monotonic generation counter for H2 pool entries.
+    h2_generation: AtomicU64,
     /// Handle for the background eviction task.
     eviction_handle: Option<tokio::task::JoinHandle<()>>,
 }
@@ -69,6 +74,7 @@ impl ConnectionPool {
         Self {
             h1_pool,
             h2_pool,
+            h2_generation: AtomicU64::new(0),
             eviction_handle: Some(eviction_handle),
         }
     }
@@ -132,22 +138,39 @@ impl ConnectionPool {
         None
     }
 
-    /// Remove a dead HTTP/2 sender from the pool.
+    /// Remove a dead HTTP/2 sender from the pool (unconditional).
     /// Called when `send_request` fails to prevent subsequent requests from reusing the stale sender.
     pub fn remove_h2(&self, key: &PoolKey) {
         self.h2_pool.remove(key);
     }
 
-    /// Register an HTTP/2 sender in the pool. Since h2 is multiplexed,
-    /// only one sender per key is stored (it's Clone-able).
-    pub fn register_h2(&self, key: PoolKey, sender: http2::SendRequest<BoxBody<Bytes, hyper::Error>>) {
+    /// Remove an HTTP/2 sender ONLY if the current entry has the expected generation.
+    /// This prevents phantom eviction: when multiple connections share the same key,
+    /// an old connection's driver won't accidentally remove a newer connection's entry.
+    pub fn remove_h2_if_generation(&self, key: &PoolKey, expected_gen: u64) {
+        if let Some(entry) = self.h2_pool.get(key) {
+            if entry.value().generation == expected_gen {
+                drop(entry); // release DashMap ref before remove
+                self.h2_pool.remove(key);
+            }
+            // else: a newer connection replaced ours — don't touch it
+        }
+    }
+
+    /// Register an HTTP/2 sender in the pool. Returns the generation ID for this entry.
+    /// The caller should pass this generation to the connection driver so it can use
+    /// `remove_h2_if_generation` instead of `remove_h2` to avoid phantom eviction.
+    pub fn register_h2(&self, key: PoolKey, sender: http2::SendRequest<BoxBody<Bytes, hyper::Error>>) -> u64 {
+        let gen = self.h2_generation.fetch_add(1, Ordering::Relaxed);
         if sender.is_closed() {
-            return;
+            return gen;
         }
         self.h2_pool.insert(key, PooledH2 {
             sender,
             created_at: Instant::now(),
+            generation: gen,
         });
+        gen
     }
 
     /// Background eviction loop — runs every EVICTION_INTERVAL to remove stale connections.

rust/crates/rustproxy-http/src/counting_body.rs

@@ -9,19 +9,28 @@ use bytes::Bytes;
 use http_body::Frame;
 use rustproxy_metrics::MetricsCollector;
 
+/// Flush accumulated bytes to the metrics collector every 64 KB.
+/// This reduces per-frame DashMap shard-locked reads from ~15 to ~1 per 4 frames
+/// (assuming typical 16 KB upload frames).  The 1 Hz throughput sampler still sees
+/// data within one sampling period even at low transfer rates.
+const BYTE_FLUSH_THRESHOLD: u64 = 65_536;
+
 /// Wraps any `http_body::Body` and counts data bytes passing through.
 ///
-/// Each chunk is reported to the `MetricsCollector` immediately so that
-/// the throughput tracker (sampled at 1 Hz) reflects real-time data flow.
+/// Bytes are accumulated and flushed to the `MetricsCollector` every
+/// [`BYTE_FLUSH_THRESHOLD`] bytes (and on Drop) so the throughput tracker
+/// (sampled at 1 Hz) reflects real-time data flow without per-frame overhead.
 ///
 /// The inner body is pinned on the heap to support `!Unpin` types like `hyper::body::Incoming`.
 pub struct CountingBody<B> {
     inner: Pin<Box<B>>,
     metrics: Arc<MetricsCollector>,
-    route_id: Option<String>,
-    source_ip: Option<String>,
+    route_id: Option<Arc<str>>,
+    source_ip: Option<Arc<str>>,
     /// Whether we count bytes as "in" (request body) or "out" (response body).
     direction: Direction,
+    /// Accumulated bytes not yet flushed to the metrics collector.
+    pending_bytes: u64,
     /// Optional connection-level activity tracker. When set, poll_frame updates this
     /// to keep the idle watchdog alive during active body streaming (uploads/downloads).
     connection_activity: Option<Arc<AtomicU64>>,
@@ -47,8 +56,8 @@ impl<B> CountingBody<B> {
     pub fn new(
         inner: B,
         metrics: Arc<MetricsCollector>,
-        route_id: Option<String>,
-        source_ip: Option<String>,
+        route_id: Option<Arc<str>>,
+        source_ip: Option<Arc<str>>,
         direction: Direction,
     ) -> Self {
         Self {
@@ -57,6 +66,7 @@ impl<B> CountingBody<B> {
             route_id,
             source_ip,
             direction,
+            pending_bytes: 0,
             connection_activity: None,
             activity_start: None,
             active_requests: None,
@@ -81,14 +91,19 @@ impl<B> CountingBody<B> {
         self
     }
 
-    /// Report a chunk of bytes immediately to the metrics collector.
+    /// Flush accumulated bytes to the metrics collector.
     #[inline]
-    fn report_chunk(&self, len: u64) {
+    fn flush_pending(&mut self) {
+        if self.pending_bytes == 0 {
+            return;
+        }
+        let bytes = self.pending_bytes;
+        self.pending_bytes = 0;
         let route_id = self.route_id.as_deref();
         let source_ip = self.source_ip.as_deref();
         match self.direction {
-            Direction::In => self.metrics.record_bytes(len, 0, route_id, source_ip),
-            Direction::Out => self.metrics.record_bytes(0, len, route_id, source_ip),
+            Direction::In => self.metrics.record_bytes(bytes, 0, route_id, source_ip),
+            Direction::Out => self.metrics.record_bytes(0, bytes, route_id, source_ip),
         }
     }
 }
@@ -113,9 +128,12 @@ where
             Poll::Ready(Some(Ok(frame))) => {
                 if let Some(data) = frame.data_ref() {
                     let len = data.len() as u64;
-                    // Report bytes immediately so the 1 Hz throughput sampler sees them
-                    this.report_chunk(len);
-                    // Keep the connection-level idle watchdog alive during body streaming
+                    this.pending_bytes += len;
+                    if this.pending_bytes >= BYTE_FLUSH_THRESHOLD {
+                        this.flush_pending();
+                    }
+                    // Keep the connection-level idle watchdog alive on every frame
+                    // (this is just one atomic store — cheap enough per-frame)
                     if let (Some(activity), Some(start)) = (&this.connection_activity, &this.activity_start) {
                         activity.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
                     }
@@ -123,7 +141,11 @@ where
                 Poll::Ready(Some(Ok(frame)))
             }
             Poll::Ready(Some(Err(e))) => Poll::Ready(Some(Err(e))),
-            Poll::Ready(None) => Poll::Ready(None),
+            Poll::Ready(None) => {
+                // End of stream — flush any remaining bytes
+                this.flush_pending();
+                Poll::Ready(None)
+            }
             Poll::Pending => Poll::Pending,
         }
     }
@@ -139,6 +161,8 @@ where
 
 impl<B> Drop for CountingBody<B> {
     fn drop(&mut self) {
+        // Flush any remaining accumulated bytes so totals stay accurate
+        self.flush_pending();
         // Decrement the active-request counter so the HTTP idle watchdog
         // knows this response body is no longer streaming.
         if let Some(ref counter) = self.active_requests {

rust/crates/rustproxy-http/src/proxy_service.rs

@@ -502,7 +502,7 @@ impl HttpProxyService {
         // Check for static file serving
         if let Some(ref advanced) = route_match.route.action.advanced {
             if let Some(ref static_files) = advanced.static_files {
-                return Ok(Self::serve_static_file(&path, static_files));
+                return Ok(Self::serve_static_file(&path, static_files).await);
             }
         }
 
@@ -615,11 +615,10 @@ impl HttpProxyService {
             };
 
             // X-Forwarded-For: append client IP to existing chain
-            let client_ip = peer_addr.ip().to_string();
             let xff_value = if let Some(existing) = upstream_headers.get("x-forwarded-for") {
-                format!("{}, {}", existing.to_str().unwrap_or(""), client_ip)
+                format!("{}, {}", existing.to_str().unwrap_or(""), ip_str)
             } else {
-                client_ip
+                ip_str.clone()
             };
             if let Ok(val) = hyper::header::HeaderValue::from_str(&xff_value) {
                 upstream_headers.insert(
@@ -677,11 +676,9 @@ impl HttpProxyService {
                 h2: use_h2,
             };
 
-            // H2 pool checkout with async readiness validation.
-            // checkout_h2 does synchronous is_closed()/is_ready() checks, but these
-            // reflect cached state — the H2 connection driver (a separate tokio task)
-            // may not have processed a pending GOAWAY/RST yet. The ready().await
-            // forces the runtime to yield, giving the driver a chance to detect failures.
+            // H2 pool checkout — reuse pooled connections for all requests.
+            // The h2 crate properly replenishes connection-level flow control
+            // windows via release_capacity() as data is consumed.
             if use_h2 {
                 if let Some((mut sender, age)) = self.connection_pool.checkout_h2(&pool_key) {
                     match tokio::time::timeout(
@@ -693,7 +690,7 @@ impl HttpProxyService {
                             self.metrics.set_backend_protocol(&upstream_key, "h2");
                             let result = self.forward_h2_pooled(
                                 sender, parts, body, upstream_headers, &upstream_path,
-                                route_match.route, route_id, &ip_str, &pool_key, domain_str, &conn_activity,
+                                route_match.route, route_id, &ip_str, &pool_key, domain_str, &conn_activity, &upstream_key,
                             ).await;
                             self.upstream_selector.connection_ended(&upstream_key);
                             return result;
@@ -846,19 +843,19 @@ impl HttpProxyService {
                 self.forward_h2_with_fallback(
                     io, parts, body, upstream_headers, &upstream_path,
                     &upstream, route_match.route, route_id, &ip_str, &final_pool_key,
-                    host.clone(), domain_str, &conn_activity,
+                    host.clone(), domain_str, &conn_activity, &upstream_key,
                 ).await
             } else {
                 // Explicit H2 mode: hard-fail on handshake error (preserved behavior)
                 self.forward_h2(
                     io, parts, body, upstream_headers, &upstream_path,
-                    &upstream, route_match.route, route_id, &ip_str, &final_pool_key, domain_str, &conn_activity,
+                    &upstream, route_match.route, route_id, &ip_str, &final_pool_key, domain_str, &conn_activity, &upstream_key,
                 ).await
             }
         } else {
             self.forward_h1(
                 io, parts, body, upstream_headers, &upstream_path,
-                &upstream, route_match.route, route_id, &ip_str, &final_pool_key, domain_str, &conn_activity,
+                &upstream, route_match.route, route_id, &ip_str, &final_pool_key, domain_str, &conn_activity, &upstream_key,
             ).await
         };
         self.upstream_selector.connection_ended(&upstream_key);
@@ -882,15 +879,14 @@ impl HttpProxyService {
         pool_key: &crate::connection_pool::PoolKey,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
-        let backend_key = format!("{}:{}", pool_key.host, pool_key.port);
-
         // Try pooled H1 connection first — avoids TCP+TLS handshake
         if let Some(pooled_sender) = self.connection_pool.checkout_h1(pool_key) {
-            self.metrics.backend_pool_hit(&backend_key);
+            self.metrics.backend_pool_hit(backend_key);
             return self.forward_h1_with_sender(
                 pooled_sender, parts, body, upstream_headers, upstream_path,
-                route, route_id, source_ip, pool_key, domain, conn_activity,
+                route, route_id, source_ip, domain, conn_activity, backend_key,
             ).await;
         }
 
@@ -902,7 +898,7 @@ impl HttpProxyService {
             Ok(h) => h,
             Err(e) => {
                 error!(backend = %backend_key, domain = %domain, error = %e, "Backend H1 handshake failed");
-                self.metrics.backend_handshake_error(&backend_key);
+                self.metrics.backend_handshake_error(backend_key);
                 return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend handshake failed"));
             }
         };
@@ -913,7 +909,7 @@ impl HttpProxyService {
             }
         });
 
-        self.forward_h1_with_sender(sender, parts, body, upstream_headers, upstream_path, route, route_id, source_ip, pool_key, domain, conn_activity).await
+        self.forward_h1_with_sender(sender, parts, body, upstream_headers, upstream_path, route, route_id, source_ip, domain, conn_activity, backend_key).await
     }
 
     /// Common H1 forwarding logic used by both fresh and pooled paths.
@@ -927,9 +923,9 @@ impl HttpProxyService {
         route: &rustproxy_config::RouteConfig,
         route_id: Option<&str>,
         source_ip: &str,
-        pool_key: &crate::connection_pool::PoolKey,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
         // Always use HTTP/1.1 for h1 backend connections (h2 incoming requests have version HTTP/2.0)
         let mut upstream_req = Request::builder()
@@ -941,12 +937,16 @@ impl HttpProxyService {
             *headers = upstream_headers;
         }
 
+        // Compute Arc<str> once for both request and response CountingBody
+        let rid: Option<Arc<str>> = route_id.map(Arc::from);
+        let sip: Arc<str> = Arc::from(source_ip);
+
         // Wrap the request body in CountingBody then box it for the uniform pool type
         let counting_req_body = CountingBody::new(
             body,
             Arc::clone(&self.metrics),
-            route_id.map(|s| s.to_string()),
-            Some(source_ip.to_string()),
+            rid.clone(),
+            Some(Arc::clone(&sip)),
             Direction::In,
         ).with_connection_activity(Arc::clone(&conn_activity.last_activity), conn_activity.start);
         let boxed_body: BoxBody<Bytes, hyper::Error> = BoxBody::new(counting_req_body);
@@ -956,9 +956,8 @@ impl HttpProxyService {
         let upstream_response = match sender.send_request(upstream_req).await {
             Ok(resp) => resp,
             Err(e) => {
-                let bk = format!("{}:{}", pool_key.host, pool_key.port);
-                error!(backend = %bk, domain = %domain, error = %e, "Backend H1 request failed");
-                self.metrics.backend_request_error(&bk);
+                error!(backend = %backend_key, domain = %domain, error = %e, "Backend H1 request failed");
+                self.metrics.backend_request_error(backend_key);
                 return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend request failed"));
             }
         };
@@ -973,7 +972,7 @@ impl HttpProxyService {
         // of large streaming responses (e.g. 352MB Docker layers) takes priority.
         drop(sender);
 
-        self.build_streaming_response(upstream_response, route, route_id, source_ip, conn_activity).await
+        self.build_streaming_response(upstream_response, route, rid, sip, conn_activity).await
     }
 
     /// Forward request to backend via HTTP/2 with body streaming (fresh connection).
@@ -992,8 +991,8 @@ impl HttpProxyService {
         pool_key: &crate::connection_pool::PoolKey,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
-        let backend_key = format!("{}:{}", pool_key.host, pool_key.port);
         let exec = hyper_util::rt::TokioExecutor::new();
         let mut h2_builder = hyper::client::conn::http2::Builder::new(exec);
         h2_builder
@@ -1009,34 +1008,42 @@ impl HttpProxyService {
             Ok(Ok(h)) => h,
             Ok(Err(e)) => {
                 error!(backend = %backend_key, domain = %domain, error = %e, error_debug = ?e, "Backend H2 handshake failed");
-                self.metrics.backend_handshake_error(&backend_key);
+                self.metrics.backend_handshake_error(backend_key);
                 return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend H2 handshake failed"));
             }
             Err(_) => {
                 error!(backend = %backend_key, domain = %domain, "Backend H2 handshake timeout");
-                self.metrics.backend_handshake_error(&backend_key);
+                self.metrics.backend_handshake_error(backend_key);
                 return Ok(error_response(StatusCode::GATEWAY_TIMEOUT, "Backend H2 handshake timeout"));
             }
         };
 
-        // Spawn the H2 connection driver; proactively evict from pool on exit
-        // so the next request gets a fresh connection instead of a dead sender.
+        // Shared generation ID: driver reads it after registration sets it.
+        // Uses u64::MAX as sentinel for "not yet registered" (driver waits/skips eviction).
+        let gen_holder = Arc::new(std::sync::atomic::AtomicU64::new(u64::MAX));
+
+        // Spawn the H2 connection driver; evict from pool on exit using generation-tagged
+        // removal to prevent phantom eviction when multiple connections share the same key.
         {
             let pool = Arc::clone(&self.connection_pool);
             let key = pool_key.clone();
+            let gen = Arc::clone(&gen_holder);
             tokio::spawn(async move {
                 if let Err(e) = conn.await {
                     warn!("HTTP/2 upstream connection error: {} ({:?})", e, e);
                 }
-                pool.remove_h2(&key);
+                let g = gen.load(std::sync::atomic::Ordering::Relaxed);
+                if g != u64::MAX {
+                    pool.remove_h2_if_generation(&key, g);
+                }
             });
         }
 
-        // Clone sender for potential pool registration; register only after first request succeeds
         let sender_for_pool = sender.clone();
-        let result = self.forward_h2_with_sender(sender, parts, body, upstream_headers, upstream_path, route, route_id, source_ip, Some(pool_key), domain, conn_activity).await;
+        let result = self.forward_h2_with_sender(sender, parts, body, upstream_headers, upstream_path, route, route_id, source_ip, Some(pool_key), domain, conn_activity, backend_key).await;
         if matches!(&result, Ok(ref resp) if resp.status() != StatusCode::BAD_GATEWAY) {
-            self.connection_pool.register_h2(pool_key.clone(), sender_for_pool);
+            let g = self.connection_pool.register_h2(pool_key.clone(), sender_for_pool);
+            gen_holder.store(g, std::sync::atomic::Ordering::Relaxed);
         }
         result
     }
@@ -1057,6 +1064,7 @@ impl HttpProxyService {
         pool_key: &crate::connection_pool::PoolKey,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
         // Save retry state for bodyless requests (cheap: Method is an enum, HeaderMap clones Arc-backed Bytes)
         let retry_state = if body.is_end_stream() {
@@ -1067,18 +1075,18 @@ impl HttpProxyService {
 
         let result = self.forward_h2_with_sender(
             sender, parts, body, upstream_headers, upstream_path,
-            route, route_id, source_ip, Some(pool_key), domain, conn_activity,
+            route, route_id, source_ip, Some(pool_key), domain, conn_activity, backend_key,
         ).await;
 
         // If the request failed (502) and we can retry with an empty body, do so
         let is_502 = matches!(&result, Ok(resp) if resp.status() == StatusCode::BAD_GATEWAY);
         if is_502 {
             if let Some((method, headers)) = retry_state {
-                warn!(backend = %format!("{}:{}", pool_key.host, pool_key.port), domain = %domain,
+                warn!(backend = %backend_key, domain = %domain,
                     "Stale pooled H2 sender, retrying with fresh connection");
                 return self.retry_h2_with_fresh_connection(
                     method, headers, upstream_path,
-                    pool_key, route, route_id, source_ip, domain, conn_activity,
+                    pool_key, route, route_id, source_ip, domain, conn_activity, backend_key,
                 ).await;
             }
         }
@@ -1098,8 +1106,8 @@ impl HttpProxyService {
         source_ip: &str,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
-        let backend_key = format!("{}:{}", pool_key.host, pool_key.port);
 
         // Establish fresh backend connection
         let retry_connect_start = std::time::Instant::now();
@@ -1111,12 +1119,12 @@ impl HttpProxyService {
                 Ok(Ok(tls)) => BackendStream::Tls(tls),
                 Ok(Err(e)) => {
                     error!(backend = %backend_key, domain = %domain, error = %e, "H2 retry: TLS connect failed");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend unavailable on H2 retry"));
                 }
                 Err(_) => {
                     error!(backend = %backend_key, domain = %domain, "H2 retry: TLS connect timeout");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     return Ok(error_response(StatusCode::GATEWAY_TIMEOUT, "Backend timeout on H2 retry"));
                 }
             }
@@ -1131,17 +1139,17 @@ impl HttpProxyService {
                 }
                 Ok(Err(e)) => {
                     error!(backend = %backend_key, domain = %domain, error = %e, "H2 retry: TCP connect failed");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend unavailable on H2 retry"));
                 }
                 Err(_) => {
                     error!(backend = %backend_key, domain = %domain, "H2 retry: TCP connect timeout");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     return Ok(error_response(StatusCode::GATEWAY_TIMEOUT, "Backend timeout on H2 retry"));
                 }
             }
         };
-        self.metrics.backend_connection_opened(&backend_key, retry_connect_start.elapsed());
+        self.metrics.backend_connection_opened(backend_key, retry_connect_start.elapsed());
 
         let io = TokioIo::new(backend);
         let exec = hyper_util::rt::TokioExecutor::new();
@@ -1159,27 +1167,32 @@ impl HttpProxyService {
             Ok(Ok(h)) => h,
             Ok(Err(e)) => {
                 error!(backend = %backend_key, domain = %domain, error = %e, error_debug = ?e, "H2 retry: handshake failed");
-                self.metrics.backend_handshake_error(&backend_key);
-                self.metrics.backend_connection_closed(&backend_key);
+                self.metrics.backend_handshake_error(backend_key);
+                self.metrics.backend_connection_closed(backend_key);
                 return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend H2 retry handshake failed"));
             }
             Err(_) => {
                 error!(backend = %backend_key, domain = %domain, "H2 retry: handshake timeout");
-                self.metrics.backend_handshake_error(&backend_key);
-                self.metrics.backend_connection_closed(&backend_key);
+                self.metrics.backend_handshake_error(backend_key);
+                self.metrics.backend_connection_closed(backend_key);
                 return Ok(error_response(StatusCode::GATEWAY_TIMEOUT, "Backend H2 retry handshake timeout"));
             }
         };
 
-        // Spawn the H2 connection driver; proactively evict from pool on exit.
+        // Spawn the H2 connection driver with generation-tagged eviction.
+        let gen_holder = Arc::new(std::sync::atomic::AtomicU64::new(u64::MAX));
         {
             let pool = Arc::clone(&self.connection_pool);
             let key = pool_key.clone();
+            let gen = Arc::clone(&gen_holder);
             tokio::spawn(async move {
                 if let Err(e) = conn.await {
                     warn!("H2 retry: upstream connection error: {} ({:?})", e, e);
                 }
-                pool.remove_h2(&key);
+                let g = gen.load(std::sync::atomic::Ordering::Relaxed);
+                if g != u64::MAX {
+                    pool.remove_h2_if_generation(&key, g);
+                }
             });
         }
 
@@ -1207,17 +1220,18 @@ impl HttpProxyService {
         match sender.send_request(upstream_req).await {
             Ok(resp) => {
                 // Register in pool only after request succeeds
-                self.connection_pool.register_h2(pool_key.clone(), sender);
-                let result = self.build_streaming_response(resp, route, route_id, source_ip, conn_activity).await;
+                let g = self.connection_pool.register_h2(pool_key.clone(), sender);
+                gen_holder.store(g, std::sync::atomic::Ordering::Relaxed);
+                let result = self.build_streaming_response(resp, route, route_id.map(Arc::from), Arc::from(source_ip), conn_activity).await;
                 // Close the fresh backend connection (opened above)
-                self.metrics.backend_connection_closed(&backend_key);
+                self.metrics.backend_connection_closed(backend_key);
                 result
             }
             Err(e) => {
                 error!(backend = %backend_key, domain = %domain, error = %e, "H2 retry: request failed");
-                self.metrics.backend_request_error(&backend_key);
+                self.metrics.backend_request_error(backend_key);
                 // Close the fresh backend connection (opened above)
-                self.metrics.backend_connection_closed(&backend_key);
+                self.metrics.backend_connection_closed(backend_key);
                 Ok(error_response(StatusCode::BAD_GATEWAY, "Backend H2 request failed on retry"))
             }
         }
@@ -1245,6 +1259,7 @@ impl HttpProxyService {
         requested_host: Option<String>,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
         let exec = hyper_util::rt::TokioExecutor::new();
         let mut h2_builder = hyper::client::conn::http2::Builder::new(exec);
@@ -1262,14 +1277,13 @@ impl HttpProxyService {
         match handshake_result {
             Err(_) => {
                 // H2 handshake timed out — fall back to H1
-                let bk = format!("{}:{}", upstream.host, upstream.port);
                 warn!(
-                    backend = %bk,
+                    backend = %backend_key,
                     domain = %domain,
                     "H2 handshake timeout, falling back to H1"
                 );
-                self.metrics.backend_h2_failure(&bk);
-                self.metrics.backend_handshake_error(&bk);
+                self.metrics.backend_h2_failure(backend_key);
+                self.metrics.backend_handshake_error(backend_key);
 
                 let cache_key = crate::protocol_cache::ProtocolCacheKey {
                     host: upstream.host.clone(),
@@ -1278,7 +1292,7 @@ impl HttpProxyService {
                 };
                 self.protocol_cache.insert(cache_key, crate::protocol_cache::DetectedProtocol::H1);
 
-                match self.reconnect_backend(upstream, domain).await {
+                match self.reconnect_backend(upstream, domain, backend_key).await {
                     Some(fallback_backend) => {
                         let h1_pool_key = crate::connection_pool::PoolKey {
                             host: upstream.host.clone(),
@@ -1289,9 +1303,9 @@ impl HttpProxyService {
                         let fallback_io = TokioIo::new(fallback_backend);
                         let result = self.forward_h1(
                             fallback_io, parts, body, upstream_headers, upstream_path,
-                            upstream, route, route_id, source_ip, &h1_pool_key, domain, conn_activity,
+                            upstream, route, route_id, source_ip, &h1_pool_key, domain, conn_activity, backend_key,
                         ).await;
-                        self.metrics.backend_connection_closed(&bk);
+                        self.metrics.backend_connection_closed(backend_key);
                         result
                     }
                     None => {
@@ -1300,15 +1314,20 @@ impl HttpProxyService {
                 }
             }
             Ok(Ok((mut sender, conn))) => {
-                // Spawn the H2 connection driver; proactively evict from pool on exit.
+                // Spawn the H2 connection driver with generation-tagged eviction.
+                let gen_holder = Arc::new(std::sync::atomic::AtomicU64::new(u64::MAX));
                 {
                     let pool = Arc::clone(&self.connection_pool);
                     let key = pool_key.clone();
+                    let gen = Arc::clone(&gen_holder);
                     tokio::spawn(async move {
                         if let Err(e) = conn.await {
                             warn!("HTTP/2 upstream connection error: {} ({:?})", e, e);
                         }
-                        pool.remove_h2(&key);
+                        let g = gen.load(std::sync::atomic::Ordering::Relaxed);
+                        if g != u64::MAX {
+                            pool.remove_h2_if_generation(&key, g);
+                        }
                     });
                 }
 
@@ -1337,11 +1356,13 @@ impl HttpProxyService {
                     *headers = upstream_headers;
                 }
 
+                let rid: Option<Arc<str>> = route_id.map(Arc::from);
+                let sip: Arc<str> = Arc::from(source_ip);
                 let counting_req_body = CountingBody::new(
                     body,
                     Arc::clone(&self.metrics),
-                    route_id.map(|s| s.to_string()),
-                    Some(source_ip.to_string()),
+                    rid.clone(),
+                    Some(Arc::clone(&sip)),
                     Direction::In,
                 ).with_connection_activity(Arc::clone(&conn_activity.last_activity), conn_activity.start);
                 let boxed_body: BoxBody<Bytes, hyper::Error> = BoxBody::new(counting_req_body);
@@ -1349,46 +1370,35 @@ impl HttpProxyService {
 
                 match sender.send_request(upstream_req).await {
                     Ok(upstream_response) => {
-                        // H2 works! Register sender in pool for multiplexed reuse
-                        self.connection_pool.register_h2(pool_key.clone(), sender);
-                        self.build_streaming_response(upstream_response, route, route_id, source_ip, conn_activity).await
+                        let g = self.connection_pool.register_h2(pool_key.clone(), sender);
+                        gen_holder.store(g, std::sync::atomic::Ordering::Relaxed);
+                        self.build_streaming_response(upstream_response, route, rid, sip, conn_activity).await
                     }
                     Err(e) => {
-                        // H2 request failed — backend advertises h2 via ALPN but doesn't
-                        // actually speak it. Update cache so future requests use H1.
-                        let bk = format!("{}:{}", upstream.host, upstream.port);
-                        warn!(
-                            backend = %bk,
+                        // H2 request failed on a stream level (e.g. RST_STREAM PROTOCOL_ERROR).
+                        // The H2 handshake succeeded, so the backend genuinely speaks H2 — don't
+                        // poison the protocol cache.  Only handshake-level failures (below) should
+                        // downgrade the cache to H1.
+                        debug!(
+                            backend = %backend_key,
                             domain = %domain,
                             error = %e,
                             error_debug = ?e,
-                            "Auto-detect: H2 request failed, falling back to H1"
+                            "H2 stream error, retrying this request as H1"
                         );
-                        self.metrics.backend_h2_failure(&bk);
-                        let cache_key = crate::protocol_cache::ProtocolCacheKey {
-                            host: upstream.host.clone(),
-                            port: upstream.port,
-                            requested_host: requested_host.clone(),
-                        };
-                        self.protocol_cache.insert(cache_key, crate::protocol_cache::DetectedProtocol::H1);
+                        self.metrics.backend_h2_failure(backend_key);
 
                         // Retry as H1 for bodyless requests; return 502 for requests with bodies
                         if let Some((method, headers)) = retry_state {
-                            match self.reconnect_backend(upstream, domain).await {
+                            match self.reconnect_backend(upstream, domain, backend_key).await {
                                 Some(fallback_backend) => {
-                                    let h1_pool_key = crate::connection_pool::PoolKey {
-                                        host: upstream.host.clone(),
-                                        port: upstream.port,
-                                        use_tls: upstream.use_tls,
-                                        h2: false,
-                                    };
                                     let fallback_io = TokioIo::new(fallback_backend);
                                     let result = self.forward_h1_empty_body(
                                         fallback_io, method, headers, upstream_path,
-                                        route, route_id, source_ip, &h1_pool_key, domain, conn_activity,
+                                        route, route_id, source_ip, domain, conn_activity, backend_key,
                                     ).await;
                                     // Close the reconnected backend connection (opened in reconnect_backend)
-                                    self.metrics.backend_connection_closed(&bk);
+                                    self.metrics.backend_connection_closed(backend_key);
                                     result
                                 }
                                 None => {
@@ -1404,15 +1414,14 @@ impl HttpProxyService {
             Ok(Err(e)) => {
                 // H2 handshake truly failed — fall back to H1
                 // Body is NOT consumed yet, so we can retry the full request.
-                let bk = format!("{}:{}", upstream.host, upstream.port);
                 warn!(
-                    backend = %bk,
+                    backend = %backend_key,
                     domain = %domain,
                     error = %e,
                     "H2 handshake failed, falling back to H1"
                 );
-                self.metrics.backend_h2_failure(&bk);
-                self.metrics.backend_handshake_error(&bk);
+                self.metrics.backend_h2_failure(backend_key);
+                self.metrics.backend_handshake_error(backend_key);
 
                 // Update cache to H1 so subsequent requests skip H2
                 let cache_key = crate::protocol_cache::ProtocolCacheKey {
@@ -1423,7 +1432,7 @@ impl HttpProxyService {
                 self.protocol_cache.insert(cache_key, crate::protocol_cache::DetectedProtocol::H1);
 
                 // Reconnect for H1 (the original io was consumed by the failed h2 handshake)
-                match self.reconnect_backend(upstream, domain).await {
+                match self.reconnect_backend(upstream, domain, backend_key).await {
                     Some(fallback_backend) => {
                         let h1_pool_key = crate::connection_pool::PoolKey {
                             host: upstream.host.clone(),
@@ -1434,10 +1443,10 @@ impl HttpProxyService {
                         let fallback_io = TokioIo::new(fallback_backend);
                         let result = self.forward_h1(
                             fallback_io, parts, body, upstream_headers, upstream_path,
-                            upstream, route, route_id, source_ip, &h1_pool_key, domain, conn_activity,
+                            upstream, route, route_id, source_ip, &h1_pool_key, domain, conn_activity, backend_key,
                         ).await;
                         // Close the reconnected backend connection (opened in reconnect_backend)
-                        self.metrics.backend_connection_closed(&bk);
+                        self.metrics.backend_connection_closed(backend_key);
                         result
                     }
                     None => {
@@ -1459,11 +1468,10 @@ impl HttpProxyService {
         route: &rustproxy_config::RouteConfig,
         route_id: Option<&str>,
         source_ip: &str,
-        pool_key: &crate::connection_pool::PoolKey,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
-        let backend_key = format!("{}:{}", pool_key.host, pool_key.port);
         let (mut sender, conn): (
             hyper::client::conn::http1::SendRequest<BoxBody<Bytes, hyper::Error>>,
             hyper::client::conn::http1::Connection<TokioIo<BackendStream>, BoxBody<Bytes, hyper::Error>>,
@@ -1471,7 +1479,7 @@ impl HttpProxyService {
             Ok(h) => h,
             Err(e) => {
                 error!(backend = %backend_key, domain = %domain, error = %e, "H1 fallback: handshake failed");
-                self.metrics.backend_handshake_error(&backend_key);
+                self.metrics.backend_handshake_error(backend_key);
                 return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend H1 fallback handshake failed"));
             }
         };
@@ -1500,7 +1508,7 @@ impl HttpProxyService {
             Ok(resp) => resp,
             Err(e) => {
                 error!(backend = %backend_key, domain = %domain, error = %e, "H1 fallback: request failed");
-                self.metrics.backend_request_error(&backend_key);
+                self.metrics.backend_request_error(backend_key);
                 return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend H1 fallback request failed"));
             }
         };
@@ -1508,7 +1516,7 @@ impl HttpProxyService {
         // Don't pool the sender while response body is still streaming (same safety as forward_h1_with_sender)
         drop(sender);
 
-        self.build_streaming_response(upstream_response, route, route_id, source_ip, conn_activity).await
+        self.build_streaming_response(upstream_response, route, route_id.map(Arc::from), Arc::from(source_ip), conn_activity).await
     }
 
     /// Reconnect to a backend (used for H2→H1 fallback).
@@ -1516,8 +1524,8 @@ impl HttpProxyService {
         &self,
         upstream: &crate::upstream_selector::UpstreamSelection,
         domain: &str,
+        backend_key: &str,
     ) -> Option<BackendStream> {
-        let backend_key = format!("{}:{}", upstream.host, upstream.port);
         let reconnect_start = std::time::Instant::now();
         if upstream.use_tls {
             match tokio::time::timeout(
@@ -1525,17 +1533,17 @@ impl HttpProxyService {
                 connect_tls_backend(&self.backend_tls_config, &upstream.host, upstream.port),
             ).await {
                 Ok(Ok(tls)) => {
-                    self.metrics.backend_connection_opened(&backend_key, reconnect_start.elapsed());
+                    self.metrics.backend_connection_opened(backend_key, reconnect_start.elapsed());
                     Some(BackendStream::Tls(tls))
                 }
                 Ok(Err(e)) => {
                     error!(backend = %backend_key, domain = %domain, error = %e, "H1 fallback: TLS reconnect failed");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     None
                 }
                 Err(_) => {
                     error!(backend = %backend_key, domain = %domain, "H1 fallback: TLS reconnect timeout");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     None
                 }
             }
@@ -1549,17 +1557,17 @@ impl HttpProxyService {
                     let _ = socket2::SockRef::from(&s).set_tcp_keepalive(
                         &socket2::TcpKeepalive::new().with_time(std::time::Duration::from_secs(60))
                     );
-                    self.metrics.backend_connection_opened(&backend_key, reconnect_start.elapsed());
+                    self.metrics.backend_connection_opened(backend_key, reconnect_start.elapsed());
                     Some(BackendStream::Plain(s))
                 }
                 Ok(Err(e)) => {
                     error!(backend = %backend_key, domain = %domain, error = %e, "H1 fallback: TCP reconnect failed");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     None
                 }
                 Err(_) => {
                     error!(backend = %backend_key, domain = %domain, "H1 fallback: TCP reconnect timeout");
-                    self.metrics.backend_connect_error(&backend_key);
+                    self.metrics.backend_connect_error(backend_key);
                     None
                 }
             }
@@ -1580,6 +1588,7 @@ impl HttpProxyService {
         pool_key: Option<&crate::connection_pool::PoolKey>,
         domain: &str,
         conn_activity: &ConnActivity,
+        backend_key: &str,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
         // Build absolute URI for H2 pseudo-headers (:scheme, :authority)
         // Use the requested domain as authority (not backend address) so :authority matches Host header
@@ -1601,12 +1610,16 @@ impl HttpProxyService {
             *headers = upstream_headers;
         }
 
+        // Compute Arc<str> once for both request and response CountingBody
+        let rid: Option<Arc<str>> = route_id.map(Arc::from);
+        let sip: Arc<str> = Arc::from(source_ip);
+
         // Wrap the request body in CountingBody then box it for the uniform pool type
         let counting_req_body = CountingBody::new(
             body,
             Arc::clone(&self.metrics),
-            route_id.map(|s| s.to_string()),
-            Some(source_ip.to_string()),
+            rid.clone(),
+            Some(Arc::clone(&sip)),
             Direction::In,
         ).with_connection_activity(Arc::clone(&conn_activity.last_activity), conn_activity.start);
         let boxed_body: BoxBody<Bytes, hyper::Error> = BoxBody::new(counting_req_body);
@@ -1618,9 +1631,8 @@ impl HttpProxyService {
             Err(e) => {
                 // Evict the dead sender so subsequent requests get fresh connections
                 if let Some(key) = pool_key {
-                    let bk = format!("{}:{}", key.host, key.port);
-                    error!(backend = %bk, domain = %domain, error = %e, error_debug = ?e, "Backend H2 request failed");
-                    self.metrics.backend_request_error(&bk);
+                    error!(backend = %backend_key, domain = %domain, error = %e, error_debug = ?e, "Backend H2 request failed");
+                    self.metrics.backend_request_error(backend_key);
                     self.connection_pool.remove_h2(key);
                 } else {
                     error!(domain = %domain, error = %e, error_debug = ?e, "Backend H2 request failed");
@@ -1629,7 +1641,7 @@ impl HttpProxyService {
             }
         };
 
-        self.build_streaming_response(upstream_response, route, route_id, source_ip, conn_activity).await
+        self.build_streaming_response(upstream_response, route, rid, sip, conn_activity).await
     }
 
     /// Build the client-facing response from an upstream response, streaming the body.
@@ -1640,8 +1652,8 @@ impl HttpProxyService {
         &self,
         upstream_response: Response<Incoming>,
         route: &rustproxy_config::RouteConfig,
-        route_id: Option<&str>,
-        source_ip: &str,
+        route_id: Option<Arc<str>>,
+        source_ip: Arc<str>,
         conn_activity: &ConnActivity,
     ) -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
         let (resp_parts, resp_body) = upstream_response.into_parts();
@@ -1673,8 +1685,8 @@ impl HttpProxyService {
         let counting_body = CountingBody::new(
             resp_body,
             Arc::clone(&self.metrics),
-            route_id.map(|s| s.to_string()),
-            Some(source_ip.to_string()),
+            route_id,
+            Some(source_ip),
             Direction::Out,
         ).with_connection_activity(Arc::clone(&conn_activity.last_activity), conn_activity.start);
 
@@ -1893,21 +1905,26 @@ impl HttpProxyService {
         }
 
         let mut response_buf = Vec::with_capacity(4096);
-        let mut temp = [0u8; 1];
+        let mut read_buf = [0u8; 4096];
+        let extra_bytes: Vec<u8>;
         loop {
-            match upstream_stream.read(&mut temp).await {
+            match upstream_stream.read(&mut read_buf).await {
                 Ok(0) => {
                     error!("WebSocket: upstream closed before completing handshake");
                     self.upstream_selector.connection_ended(upstream_key);
                     return Ok(error_response(StatusCode::BAD_GATEWAY, "Backend closed"));
                 }
-                Ok(_) => {
-                    response_buf.push(temp[0]);
-                    if response_buf.len() >= 4 {
-                        let len = response_buf.len();
-                        if response_buf[len-4..] == *b"\r\n\r\n" {
-                            break;
-                        }
+                Ok(n) => {
+                    let prev_len = response_buf.len();
+                    response_buf.extend_from_slice(&read_buf[..n]);
+                    // Scan for \r\n\r\n, backing up 3 bytes to handle split across reads
+                    let search_start = prev_len.saturating_sub(3);
+                    if let Some(pos) = response_buf[search_start..].windows(4)
+                        .position(|w| w == b"\r\n\r\n")
+                    {
+                        let header_end = search_start + pos + 4;
+                        extra_bytes = response_buf.split_off(header_end);
+                        break;
                     }
                     if response_buf.len() > 8192 {
                         error!("WebSocket: upstream response headers too large");
@@ -1982,8 +1999,8 @@ impl HttpProxyService {
         );
 
         let metrics = Arc::clone(&self.metrics);
-        let route_id_owned = route_id.map(|s| s.to_string());
-        let source_ip_owned = source_ip.to_string();
+        let route_id_owned: Option<Arc<str>> = route_id.map(Arc::from);
+        let source_ip_owned: Arc<str> = Arc::from(source_ip);
         let upstream_selector = self.upstream_selector.clone();
         let upstream_key_owned = upstream_key.to_string();
         let ws_inactivity_timeout = self.ws_inactivity_timeout;
@@ -2037,7 +2054,7 @@ impl HttpProxyService {
                         break;
                     }
                     total += n as u64;
-                    metrics_c2u.record_bytes(n as u64, 0, route_c2u.as_deref(), Some(&ip_c2u));
+                    metrics_c2u.record_bytes(n as u64, 0, route_c2u.as_deref(), Some(&*ip_c2u));
                     la1.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
                     if let Some((ref ca, ca_start)) = conn_act_c2u {
                         ca.store(ca_start.elapsed().as_millis() as u64, Ordering::Relaxed);
@@ -2059,6 +2076,23 @@ impl HttpProxyService {
             let u2c = tokio::spawn(async move {
                 let mut buf = vec![0u8; 65536];
                 let mut total = 0u64;
+                // Forward any bytes buffered past the HTTP header terminator during handshake
+                if !extra_bytes.is_empty() {
+                    let n = extra_bytes.len();
+                    if cw.write_all(&extra_bytes).await.is_err() {
+                        let _ = tokio::time::timeout(
+                            std::time::Duration::from_secs(2),
+                            cw.shutdown(),
+                        ).await;
+                        return 0u64;
+                    }
+                    total += n as u64;
+                    metrics_u2c.record_bytes(0, n as u64, route_u2c.as_deref(), Some(&*ip_u2c));
+                    la2.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
+                    if let Some((ref ca, ca_start)) = conn_act_u2c {
+                        ca.store(ca_start.elapsed().as_millis() as u64, Ordering::Relaxed);
+                    }
+                }
                 loop {
                     let n = tokio::select! {
                         result = ur.read(&mut buf) => match result {
@@ -2071,7 +2105,7 @@ impl HttpProxyService {
                         break;
                     }
                     total += n as u64;
-                    metrics_u2c.record_bytes(0, n as u64, route_u2c.as_deref(), Some(&ip_u2c));
+                    metrics_u2c.record_bytes(0, n as u64, route_u2c.as_deref(), Some(&*ip_u2c));
                     la2.store(start.elapsed().as_millis() as u64, Ordering::Relaxed);
                     if let Some((ref ca, ca_start)) = conn_act_u2c {
                         ca.store(ca_start.elapsed().as_millis() as u64, Ordering::Relaxed);
@@ -2211,13 +2245,13 @@ impl HttpProxyService {
     }
 
     /// Serve a static file from the configured directory.
-    fn serve_static_file(
+    async fn serve_static_file(
         path: &str,
         config: &rustproxy_config::RouteStaticFiles,
     ) -> Response<BoxBody<Bytes, hyper::Error>> {
-        use std::path::Path;
+        use std::path::PathBuf;
 
-        let root = Path::new(&config.root);
+        let root = PathBuf::from(&config.root);
 
         // Sanitize path to prevent directory traversal
         let clean_path = path.trim_start_matches('/');
@@ -2226,7 +2260,12 @@ impl HttpProxyService {
         let mut file_path = root.join(&clean_path);
 
         // If path points to a directory, try index files
-        if file_path.is_dir() || clean_path.is_empty() {
+        let is_dir = if clean_path.is_empty() {
+            true
+        } else {
+            tokio::fs::metadata(&file_path).await.map(|m| m.is_dir()).unwrap_or(false)
+        };
+        if is_dir {
             let index_files = config.index_files.as_deref()
                 .or(config.index.as_deref())
                 .unwrap_or(&[]);
@@ -2240,7 +2279,7 @@ impl HttpProxyService {
                 } else {
                     file_path.join(index)
                 };
-                if candidate.is_file() {
+                if tokio::fs::metadata(&candidate).await.map(|m| m.is_file()).unwrap_or(false) {
                     file_path = candidate;
                     found = true;
                     break;
@@ -2252,11 +2291,11 @@ impl HttpProxyService {
         }
 
         // Ensure the resolved path is within the root (prevent traversal)
-        let canonical_root = match root.canonicalize() {
+        let canonical_root = match tokio::fs::canonicalize(&root).await {
             Ok(p) => p,
             Err(_) => return error_response(StatusCode::NOT_FOUND, "Not found"),
         };
-        let canonical_file = match file_path.canonicalize() {
+        let canonical_file = match tokio::fs::canonicalize(&file_path).await {
             Ok(p) => p,
             Err(_) => return error_response(StatusCode::NOT_FOUND, "Not found"),
         };
@@ -2270,7 +2309,7 @@ impl HttpProxyService {
         }
 
         // Read the file
-        match std::fs::read(&file_path) {
+        match tokio::fs::read(&file_path).await {
             Ok(content) => {
                 let content_type = guess_content_type(&file_path);
                 let mut response = Response::builder()

rust/crates/rustproxy-metrics/src/collector.rs

@@ -259,40 +259,49 @@ impl MetricsCollector {
     /// Called per-chunk in the TCP copy loop. Only touches AtomicU64 counters —
     /// no Mutex is taken. The throughput trackers are fed during `sample_all()`.
     pub fn record_bytes(&self, bytes_in: u64, bytes_out: u64, route_id: Option<&str>, source_ip: Option<&str>) {
-        self.total_bytes_in.fetch_add(bytes_in, Ordering::Relaxed);
-        self.total_bytes_out.fetch_add(bytes_out, Ordering::Relaxed);
-
-        // Accumulate into lock-free pending throughput counters
-        self.global_pending_tp_in.fetch_add(bytes_in, Ordering::Relaxed);
-        self.global_pending_tp_out.fetch_add(bytes_out, Ordering::Relaxed);
+        // Short-circuit: only touch counters for the direction that has data.
+        // CountingBody always calls with one direction zero — skipping the zero
+        // direction avoids ~50% of DashMap shard-locked reads per call.
+        if bytes_in > 0 {
+            self.total_bytes_in.fetch_add(bytes_in, Ordering::Relaxed);
+            self.global_pending_tp_in.fetch_add(bytes_in, Ordering::Relaxed);
+        }
+        if bytes_out > 0 {
+            self.total_bytes_out.fetch_add(bytes_out, Ordering::Relaxed);
+            self.global_pending_tp_out.fetch_add(bytes_out, Ordering::Relaxed);
+        }
 
         // Per-route tracking: use get() first (zero-alloc fast path for existing entries),
         // fall back to entry() with to_string() only on the rare first-chunk miss.
         if let Some(route_id) = route_id {
-            if let Some(counter) = self.route_bytes_in.get(route_id) {
-                counter.fetch_add(bytes_in, Ordering::Relaxed);
-            } else {
-                self.route_bytes_in.entry(route_id.to_string())
-                    .or_insert_with(|| AtomicU64::new(0))
-                    .fetch_add(bytes_in, Ordering::Relaxed);
+            if bytes_in > 0 {
+                if let Some(counter) = self.route_bytes_in.get(route_id) {
+                    counter.fetch_add(bytes_in, Ordering::Relaxed);
+                } else {
+                    self.route_bytes_in.entry(route_id.to_string())
+                        .or_insert_with(|| AtomicU64::new(0))
+                        .fetch_add(bytes_in, Ordering::Relaxed);
+                }
             }
-            if let Some(counter) = self.route_bytes_out.get(route_id) {
-                counter.fetch_add(bytes_out, Ordering::Relaxed);
-            } else {
-                self.route_bytes_out.entry(route_id.to_string())
-                    .or_insert_with(|| AtomicU64::new(0))
-                    .fetch_add(bytes_out, Ordering::Relaxed);
+            if bytes_out > 0 {
+                if let Some(counter) = self.route_bytes_out.get(route_id) {
+                    counter.fetch_add(bytes_out, Ordering::Relaxed);
+                } else {
+                    self.route_bytes_out.entry(route_id.to_string())
+                        .or_insert_with(|| AtomicU64::new(0))
+                        .fetch_add(bytes_out, Ordering::Relaxed);
+                }
             }
 
             // Accumulate into per-route pending throughput counters (lock-free)
             if let Some(entry) = self.route_pending_tp.get(route_id) {
-                entry.0.fetch_add(bytes_in, Ordering::Relaxed);
-                entry.1.fetch_add(bytes_out, Ordering::Relaxed);
+                if bytes_in > 0 { entry.0.fetch_add(bytes_in, Ordering::Relaxed); }
+                if bytes_out > 0 { entry.1.fetch_add(bytes_out, Ordering::Relaxed); }
             } else {
                 let entry = self.route_pending_tp.entry(route_id.to_string())
                     .or_insert_with(|| (AtomicU64::new(0), AtomicU64::new(0)));
-                entry.0.fetch_add(bytes_in, Ordering::Relaxed);
-                entry.1.fetch_add(bytes_out, Ordering::Relaxed);
+                if bytes_in > 0 { entry.0.fetch_add(bytes_in, Ordering::Relaxed); }
+                if bytes_out > 0 { entry.1.fetch_add(bytes_out, Ordering::Relaxed); }
             }
         }
 
@@ -302,30 +311,34 @@ impl MetricsCollector {
             // This prevents orphaned entries when record_bytes races with
             // connection_closed (which evicts all per-IP data on last close).
             if self.ip_connections.contains_key(ip) {
-                if let Some(counter) = self.ip_bytes_in.get(ip) {
-                    counter.fetch_add(bytes_in, Ordering::Relaxed);
-                } else {
-                    self.ip_bytes_in.entry(ip.to_string())
-                        .or_insert_with(|| AtomicU64::new(0))
-                        .fetch_add(bytes_in, Ordering::Relaxed);
+                if bytes_in > 0 {
+                    if let Some(counter) = self.ip_bytes_in.get(ip) {
+                        counter.fetch_add(bytes_in, Ordering::Relaxed);
+                    } else {
+                        self.ip_bytes_in.entry(ip.to_string())
+                            .or_insert_with(|| AtomicU64::new(0))
+                            .fetch_add(bytes_in, Ordering::Relaxed);
+                    }
                 }
-                if let Some(counter) = self.ip_bytes_out.get(ip) {
-                    counter.fetch_add(bytes_out, Ordering::Relaxed);
-                } else {
-                    self.ip_bytes_out.entry(ip.to_string())
-                        .or_insert_with(|| AtomicU64::new(0))
-                        .fetch_add(bytes_out, Ordering::Relaxed);
+                if bytes_out > 0 {
+                    if let Some(counter) = self.ip_bytes_out.get(ip) {
+                        counter.fetch_add(bytes_out, Ordering::Relaxed);
+                    } else {
+                        self.ip_bytes_out.entry(ip.to_string())
+                            .or_insert_with(|| AtomicU64::new(0))
+                            .fetch_add(bytes_out, Ordering::Relaxed);
+                    }
                 }
 
                 // Accumulate into per-IP pending throughput counters (lock-free)
                 if let Some(entry) = self.ip_pending_tp.get(ip) {
-                    entry.0.fetch_add(bytes_in, Ordering::Relaxed);
-                    entry.1.fetch_add(bytes_out, Ordering::Relaxed);
+                    if bytes_in > 0 { entry.0.fetch_add(bytes_in, Ordering::Relaxed); }
+                    if bytes_out > 0 { entry.1.fetch_add(bytes_out, Ordering::Relaxed); }
                 } else {
                     let entry = self.ip_pending_tp.entry(ip.to_string())
                         .or_insert_with(|| (AtomicU64::new(0), AtomicU64::new(0)));
-                    entry.0.fetch_add(bytes_in, Ordering::Relaxed);
-                    entry.1.fetch_add(bytes_out, Ordering::Relaxed);
+                    if bytes_in > 0 { entry.0.fetch_add(bytes_in, Ordering::Relaxed); }
+                    if bytes_out > 0 { entry.1.fetch_add(bytes_out, Ordering::Relaxed); }
                 }
             }
         }

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartproxy',
-  version: '25.11.16',
+  version: '25.11.24',
   description: 'A powerful proxy package with unified route-based configuration for high traffic management. Features include SSL/TLS support, flexible routing patterns, WebSocket handling, advanced security options, and automatic ACME certificate management.'
 }