fix(protocol): increase per-stream flow control windows and remove adaptive read caps

changelog.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 2026-03-17 - 4.8.17 - fix(protocol)
+increase per-stream flow control windows and remove adaptive read caps
+
+- Raise the initial per-stream window from 4MB to 16MB and expand the adaptive window budget to 800MB with a 4MB floor
+- Stop limiting edge and hub reads by the adaptive per-stream target window, keeping reads capped only by the current window and 32KB chunk size
+- Update protocol tests to match the new adaptive window scaling and budget boundaries
+
 ## 2026-03-17 - 4.8.16 - fix(release)
 bump package version to 4.8.15
 

rust/crates/remoteingress-core/src/edge.rs

@@ -862,11 +862,7 @@ async fn handle_client_connection(
             log::warn!("Stream {} upload: window still 0 after stall timeout, closing", stream_id);
             break;
         }
-        // Adaptive: cap read to current per-stream target window
-        let adaptive_cap = remoteingress_protocol::compute_window_for_stream_count(
-            active_streams.load(Ordering::Relaxed),
-        ) as usize;
-        let max_read = w.min(32768).min(adaptive_cap);
+        let max_read = w.min(32768);
 
         tokio::select! {
             read_result = client_read.read(&mut buf[FRAME_HEADER_SIZE..FRAME_HEADER_SIZE + max_read]) => {

rust/crates/remoteingress-core/src/hub.rs

@@ -487,11 +487,7 @@ async fn handle_hub_frame(
                             log::warn!("Stream {} download: window still 0 after stall timeout, closing", stream_id);
                             break;
                         }
-                        // Adaptive: cap read to current per-stream target window
-                        let adaptive_cap = remoteingress_protocol::compute_window_for_stream_count(
-                            stream_counter.load(Ordering::Relaxed),
-                        ) as usize;
-                        let max_read = w.min(32768).min(adaptive_cap);
+                        let max_read = w.min(32768);
 
                         tokio::select! {
                             read_result = up_read.read(&mut buf[FRAME_HEADER_SIZE..FRAME_HEADER_SIZE + max_read]) => {

rust/crates/remoteingress-protocol/src/lib.rs

@@ -23,9 +23,8 @@ pub const FRAME_HEADER_SIZE: usize = 9;
 pub const MAX_PAYLOAD_SIZE: u32 = 16 * 1024 * 1024;
 
 // Per-stream flow control constants
-/// Initial per-stream window size (4 MB). Sized for full throughput at high RTT:
-/// at 100ms RTT, this sustains ~40 MB/s per stream.
-pub const INITIAL_STREAM_WINDOW: u32 = 4 * 1024 * 1024;
+/// Initial (and maximum) per-stream window size (16 MB).
+pub const INITIAL_STREAM_WINDOW: u32 = 16 * 1024 * 1024;
 /// Send WINDOW_UPDATE after consuming this many bytes (half the initial window).
 pub const WINDOW_UPDATE_THRESHOLD: u32 = INITIAL_STREAM_WINDOW / 2;
 /// Maximum window size to prevent overflow.
@@ -37,12 +36,11 @@ pub fn encode_window_update(stream_id: u32, frame_type: u8, increment: u32) -> V
 }
 
 /// Compute the target per-stream window size based on the number of active streams.
-/// Total memory budget is ~32MB shared across all streams. As more streams are active,
-/// each gets a smaller window. This adapts to current demand — few streams get high
-/// throughput, many streams save memory and reduce control frame pressure.
+/// Total memory budget is ~800MB shared across all streams. Up to 50 streams get the
+/// full 16MB window; above that the window scales down to a 4MB floor at 200+ streams.
 pub fn compute_window_for_stream_count(active: u32) -> u32 {
-    let per_stream = (32 * 1024 * 1024u64) / (active.max(1) as u64);
-    per_stream.clamp(64 * 1024, INITIAL_STREAM_WINDOW as u64) as u32
+    let per_stream = (800 * 1024 * 1024u64) / (active.max(1) as u64);
+    per_stream.clamp(4 * 1024 * 1024, INITIAL_STREAM_WINDOW as u64) as u32
 }
 
 /// Decode a WINDOW_UPDATE payload into a byte increment. Returns None if payload is malformed.
@@ -683,90 +681,57 @@ mod tests {
 
     #[test]
     fn test_adaptive_window_zero_streams() {
-        // 0 streams treated as 1: 32MB/1 = 32MB → clamped to 4MB max
+        // 0 streams treated as 1: 800MB/1 → clamped to 16MB max
         assert_eq!(compute_window_for_stream_count(0), INITIAL_STREAM_WINDOW);
     }
 
     #[test]
     fn test_adaptive_window_one_stream() {
-        // 32MB/1 = 32MB → clamped to 4MB max
         assert_eq!(compute_window_for_stream_count(1), INITIAL_STREAM_WINDOW);
     }
 
     #[test]
-    fn test_adaptive_window_at_max_boundary() {
-        // 32MB/8 = 4MB = exactly INITIAL_STREAM_WINDOW
-        assert_eq!(compute_window_for_stream_count(8), INITIAL_STREAM_WINDOW);
+    fn test_adaptive_window_50_streams_full() {
+        // 800MB/50 = 16MB = exactly INITIAL_STREAM_WINDOW
+        assert_eq!(compute_window_for_stream_count(50), INITIAL_STREAM_WINDOW);
     }
 
     #[test]
-    fn test_adaptive_window_just_below_max() {
-        // 32MB/9 = 3,728,270 — first value below INITIAL_STREAM_WINDOW
-        let w = compute_window_for_stream_count(9);
+    fn test_adaptive_window_51_streams_starts_scaling() {
+        // 800MB/51 < 16MB — first value below max
+        let w = compute_window_for_stream_count(51);
         assert!(w < INITIAL_STREAM_WINDOW);
-        assert_eq!(w, (32 * 1024 * 1024u64 / 9) as u32);
-    }
-
-    #[test]
-    fn test_adaptive_window_16_streams() {
-        // 32MB/16 = 2MB
-        assert_eq!(compute_window_for_stream_count(16), 2 * 1024 * 1024);
+        assert_eq!(w, (800 * 1024 * 1024u64 / 51) as u32);
     }
 
     #[test]
     fn test_adaptive_window_100_streams() {
-        // 32MB/100 = 335,544 bytes (~327KB)
-        let w = compute_window_for_stream_count(100);
-        assert_eq!(w, (32 * 1024 * 1024u64 / 100) as u32);
-        assert!(w > 64 * 1024); // above floor
-        assert!(w < INITIAL_STREAM_WINDOW as u32); // below ceiling
+        // 800MB/100 = 8MB
+        assert_eq!(compute_window_for_stream_count(100), 8 * 1024 * 1024);
     }
 
     #[test]
-    fn test_adaptive_window_200_streams() {
-        // 32MB/200 = 167,772 bytes (~163KB), above 64KB floor
-        let w = compute_window_for_stream_count(200);
-        assert_eq!(w, (32 * 1024 * 1024u64 / 200) as u32);
-        assert!(w > 64 * 1024);
+    fn test_adaptive_window_200_streams_at_floor() {
+        // 800MB/200 = 4MB = exactly the floor
+        assert_eq!(compute_window_for_stream_count(200), 4 * 1024 * 1024);
     }
 
     #[test]
-    fn test_adaptive_window_500_streams() {
-        // 32MB/500 = 67,108 bytes (~65.5KB), just above 64KB floor
-        let w = compute_window_for_stream_count(500);
-        assert_eq!(w, (32 * 1024 * 1024u64 / 500) as u32);
-        assert!(w > 64 * 1024);
-    }
-
-    #[test]
-    fn test_adaptive_window_at_min_boundary() {
-        // 32MB/512 = 65,536 = exactly 64KB floor
-        assert_eq!(compute_window_for_stream_count(512), 64 * 1024);
-    }
-
-    #[test]
-    fn test_adaptive_window_below_min_clamped() {
-        // 32MB/513 = 65,408 → clamped up to 64KB
-        assert_eq!(compute_window_for_stream_count(513), 64 * 1024);
-    }
-
-    #[test]
-    fn test_adaptive_window_1000_streams() {
-        // 32MB/1000 = 33,554 → clamped to 64KB
-        assert_eq!(compute_window_for_stream_count(1000), 64 * 1024);
+    fn test_adaptive_window_500_streams_clamped() {
+        // 800MB/500 = 1.6MB → clamped up to 4MB floor
+        assert_eq!(compute_window_for_stream_count(500), 4 * 1024 * 1024);
     }
 
     #[test]
     fn test_adaptive_window_max_u32() {
-        // Extreme: u32::MAX streams → tiny value → clamped to 64KB
-        assert_eq!(compute_window_for_stream_count(u32::MAX), 64 * 1024);
+        // Extreme: u32::MAX streams → tiny value → clamped to 4MB
+        assert_eq!(compute_window_for_stream_count(u32::MAX), 4 * 1024 * 1024);
     }
 
     #[test]
     fn test_adaptive_window_monotonically_decreasing() {
-        // Window should decrease (or stay same) as stream count increases
         let mut prev = compute_window_for_stream_count(1);
-        for n in [2, 5, 10, 50, 100, 200, 500, 512, 1000] {
+        for n in [2, 10, 50, 51, 100, 200, 500, 1000] {
             let w = compute_window_for_stream_count(n);
             assert!(w <= prev, "window increased from {} to {} at n={}", prev, w, n);
             prev = w;
@@ -775,11 +740,11 @@ mod tests {
 
     #[test]
     fn test_adaptive_window_total_budget_bounded() {
-        // active × per_stream_window should never exceed 32MB (+ clamp overhead for high N)
-        for n in [1, 10, 50, 100, 200, 500] {
+        // active × per_stream_window should never exceed 800MB (+ clamp overhead for high N)
+        for n in [1, 10, 50, 100, 200] {
             let w = compute_window_for_stream_count(n);
             let total = w as u64 * n as u64;
-            assert!(total <= 32 * 1024 * 1024, "total {}MB exceeds budget at n={}", total / (1024*1024), n);
+            assert!(total <= 800 * 1024 * 1024, "total {}MB exceeds budget at n={}", total / (1024*1024), n);
         }
     }
 

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@serve.zone/remoteingress',
-  version: '4.8.16',
+  version: '4.8.17',
   description: 'Edge ingress tunnel for DcRouter - accepts incoming TCP connections at network edge and tunnels them to DcRouter SmartProxy preserving client IP via PROXY protocol v1.'
 }