From bbf261ae4a9deaaacd6f570fc92cee23fd9a4342 Mon Sep 17 00:00:00 2001
From: Simo Lin <linsimo.mark@gmail.com>
Date: Thu, 4 Sep 2025 00:36:16 -0400
Subject: [PATCH] [router] fix grpc connection mode detection (#9999)

---
 sgl-router/src/core/worker.rs |  2 +-
 sgl-router/src/lib.rs         | 16 ++--------------
 sgl-router/src/main.rs        | 16 ++--------------
 3 files changed, 5 insertions(+), 29 deletions(-)

diff --git a/sgl-router/src/core/worker.rs b/sgl-router/src/core/worker.rs
index 51c3cdd65..f25fc6eea 100644
--- a/sgl-router/src/core/worker.rs
+++ b/sgl-router/src/core/worker.rs
@@ -986,7 +986,7 @@ pub fn start_health_checker(
 
             // Periodically reset load counters to prevent drift
             // Only do this when we believe all workers should be idle
-            if check_count % LOAD_RESET_INTERVAL == 0 {
+            if check_count.is_multiple_of(LOAD_RESET_INTERVAL) {
                 let max_load = workers_to_check.iter().map(|w| w.load()).max().unwrap_or(0);
                 // Only reset if load appears to be very low (likely drift)
                 if max_load <= 2 {
diff --git a/sgl-router/src/lib.rs b/sgl-router/src/lib.rs
index 955185e07..938a1ba0c 100644
--- a/sgl-router/src/lib.rs
+++ b/sgl-router/src/lib.rs
@@ -101,25 +101,13 @@ struct Router {
 impl Router {
     /// Determine connection mode from worker URLs
     fn determine_connection_mode(worker_urls: &[String]) -> config::ConnectionMode {
-        // Check if any URL is a gRPC endpoint (starts with grpc:// or has port that commonly indicates gRPC)
+        // Only consider it gRPC if explicitly specified with grpc:// or grpcs:// scheme
         for url in worker_urls {
             if url.starts_with("grpc://") || url.starts_with("grpcs://") {
                 return config::ConnectionMode::Grpc;
             }
-            // Also check for common gRPC ports if the scheme isn't specified
-            if let Ok(parsed_url) = url::Url::parse(url) {
-                if let Some(port) = parsed_url.port() {
-                    // Common gRPC ports
-                    if port == 50051 || port == 9090 || ((50000..=50100).contains(&port)) {
-                        return config::ConnectionMode::Grpc;
-                    }
-                }
-            } else if url.contains(":50051") || url.contains(":9090") || url.contains(":5000") {
-                // Fallback check for URLs that might not parse correctly
-                return config::ConnectionMode::Grpc;
-            }
         }
-        // Default to HTTP
+        // Default to HTTP for all other cases (including http://, https://, or no scheme)
         config::ConnectionMode::Http
     }
 
diff --git a/sgl-router/src/main.rs b/sgl-router/src/main.rs
index c745c0b3b..60986bbea 100644
--- a/sgl-router/src/main.rs
+++ b/sgl-router/src/main.rs
@@ -286,25 +286,13 @@ struct CliArgs {
 impl CliArgs {
     /// Determine connection mode from worker URLs
     fn determine_connection_mode(worker_urls: &[String]) -> ConnectionMode {
-        // Check if any URL is a gRPC endpoint (starts with grpc:// or has port that commonly indicates gRPC)
+        // Only consider it gRPC if explicitly specified with grpc:// or grpcs:// scheme
         for url in worker_urls {
             if url.starts_with("grpc://") || url.starts_with("grpcs://") {
                 return ConnectionMode::Grpc;
             }
-            // Also check for common gRPC ports if the scheme isn't specified
-            if let Ok(parsed_url) = url::Url::parse(url) {
-                if let Some(port) = parsed_url.port() {
-                    // Common gRPC ports
-                    if port == 50051 || port == 9090 || ((50000..=50100).contains(&port)) {
-                        return ConnectionMode::Grpc;
-                    }
-                }
-            } else if url.contains(":50051") || url.contains(":9090") || url.contains(":5000") {
-                // Fallback check for URLs that might not parse correctly
-                return ConnectionMode::Grpc;
-            }
         }
-        // Default to HTTP
+        // Default to HTTP for all other cases (including http://, https://, or no scheme)
         ConnectionMode::Http
     }