Grpc client (#9939)

sgl-router/src/core/worker.rs

 use super::{CircuitBreaker, CircuitBreakerConfig, WorkerError, WorkerResult};
+use crate::grpc::SglangSchedulerClient;
 use crate::metrics::RouterMetrics;
 use async_trait::async_trait;
 use futures;
@@ -6,6 +7,7 @@ use serde_json;
 use std::fmt;
 use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
 use std::sync::{Arc, LazyLock};
+use tokio::sync::Mutex;
 
 // Shared HTTP client for worker operations (health checks, server info, etc.)
 static WORKER_CLIENT: LazyLock<reqwest::Client> = LazyLock::new(|| {
@@ -249,7 +251,7 @@ pub struct WorkerMetadata {
 }
 
 /// Basic worker implementation
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct BasicWorker {
     metadata: WorkerMetadata,
     load_counter: Arc<AtomicUsize>,
@@ -258,6 +260,19 @@ pub struct BasicWorker {
     consecutive_failures: Arc<AtomicUsize>,
     consecutive_successes: Arc<AtomicUsize>,
     circuit_breaker: CircuitBreaker,
+    /// Optional gRPC client for gRPC workers
+    grpc_client: Option<Arc<Mutex<SglangSchedulerClient>>>,
+}
+
+impl fmt::Debug for BasicWorker {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BasicWorker")
+            .field("metadata", &self.metadata)
+            .field("healthy", &self.healthy.load(Ordering::Relaxed))
+            .field("circuit_breaker", &self.circuit_breaker)
+            .field("has_grpc_client", &self.grpc_client.is_some())
+            .finish()
+    }
 }
 
 impl BasicWorker {
@@ -286,6 +301,7 @@ impl BasicWorker {
             consecutive_failures: Arc::new(AtomicUsize::new(0)),
             consecutive_successes: Arc::new(AtomicUsize::new(0)),
             circuit_breaker: CircuitBreaker::new(),
+            grpc_client: None,
         }
     }
 
@@ -304,6 +320,12 @@ impl BasicWorker {
         self
     }
 
+    /// Set the gRPC client for gRPC workers
+    pub fn with_grpc_client(mut self, client: SglangSchedulerClient) -> Self {
+        self.grpc_client = Some(Arc::new(Mutex::new(client)));
+        self
+    }
+
     pub fn normalised_url(&self) -> WorkerResult<&str> {
         if self.url().contains("@") {
             // Need to extract the URL from "http://host:port@dp_rank"
@@ -352,15 +374,46 @@ impl Worker for BasicWorker {
     async fn check_health_async(&self) -> WorkerResult<()> {
         use std::time::Duration;
 
-        // Perform actual HTTP health check
+        let health_result = match &self.metadata.connection_mode {
+            ConnectionMode::Http => {
+                // Perform HTTP health check
                 let url = self.normalised_url()?;
                 let health_url = format!("{}{}", url, self.metadata.health_config.endpoint);
                 let timeout = Duration::from_secs(self.metadata.health_config.timeout_secs);
 
                 // Use the shared client with a custom timeout for this request
-        let health_result = match WORKER_CLIENT.get(&health_url).timeout(timeout).send().await {
+                match WORKER_CLIENT.get(&health_url).timeout(timeout).send().await {
                     Ok(response) => response.status().is_success(),
                     Err(_) => false,
+                }
+            }
+            ConnectionMode::Grpc { .. } => {
+                // Perform gRPC health check
+                if let Some(grpc_client) = &self.grpc_client {
+                    let mut client = grpc_client.lock().await;
+                    match client.health_check().await {
+                        Ok(response) => {
+                            tracing::debug!(
+                                "gRPC health check succeeded for {}: healthy={}",
+                                self.metadata.url,
+                                response.healthy
+                            );
+                            response.healthy
+                        }
+                        Err(e) => {
+                            tracing::warn!(
+                                "gRPC health check RPC failed for {}: {:?}",
+                                self.metadata.url,
+                                e
+                            );
+                            false
+                        }
+                    }
+                } else {
+                    tracing::error!("No gRPC client available for worker {}", self.metadata.url);
+                    false
+                }
+            }
         };
 
         if health_result {
@@ -390,7 +443,7 @@ impl Worker for BasicWorker {
             }
 
             Err(WorkerError::HealthCheckFailed {
-                url: url.to_string(),
+                url: self.metadata.url.clone(),
                 reason: format!("Health check failed (consecutive failures: {})", failures),
             })
         }
@@ -1491,12 +1544,17 @@ mod tests {
         // Clone for use inside catch_unwind
         let worker_clone = Arc::clone(&worker);
 
+        // Use AssertUnwindSafe wrapper for the test
+        // This is safe because we're only testing the load counter behavior,
+        // not the grpc_client which is None for HTTP workers
+        use std::panic::AssertUnwindSafe;
+
         // This will panic, but the guard should still clean up
-        let result = std::panic::catch_unwind(|| {
+        let result = std::panic::catch_unwind(AssertUnwindSafe(|| {
             let _guard = WorkerLoadGuard::new(worker_clone.as_ref());
             assert_eq!(worker_clone.load(), 1);
             panic!("Test panic");
-        });
+        }));
 
         // Verify panic occurred
         assert!(result.is_err());

sgl-router/src/grpc/client.rs

@@ -20,7 +20,14 @@ impl SglangSchedulerClient {
     pub async fn connect(endpoint: &str) -> Result<Self, Box<dyn std::error::Error>> {
         debug!("Connecting to SGLang scheduler at {}", endpoint);
 
-        let channel = Channel::from_shared(endpoint.to_string())?
+        // Convert grpc:// to http:// for tonic
+        let http_endpoint = if endpoint.starts_with("grpc://") {
+            endpoint.replace("grpc://", "http://")
+        } else {
+            endpoint.to_string()
+        };
+
+        let channel = Channel::from_shared(http_endpoint)?
             .timeout(Duration::from_secs(30))
             .connect()
             .await?;
@@ -59,11 +66,13 @@ impl SglangSchedulerClient {
     pub async fn health_check(
         &mut self,
     ) -> Result<proto::HealthCheckResponse, Box<dyn std::error::Error>> {
+        debug!("Sending health check request");
         let request = Request::new(proto::HealthCheckRequest {
             include_detailed_metrics: false,
         });
 
         let response = self.client.health_check(request).await?;
+        debug!("Health check response received");
         Ok(response.into_inner())
     }
 

sgl-router/src/routers/grpc/router.rs

@@ -108,9 +108,11 @@ impl GrpcRouter {
         }
 
         // Create Worker trait objects with gRPC connection mode
-        let workers: Vec<Box<dyn Worker>> = worker_urls
-            .iter()
-            .map(|url| {
+        let mut workers: Vec<Box<dyn Worker>> = Vec::new();
+
+        // Move clients from the HashMap to the workers
+        for url in &worker_urls {
+            if let Some(client) = grpc_clients.remove(url) {
                 let worker = BasicWorker::with_connection_mode(
                     url.clone(),
                     WorkerType::Regular,
@@ -123,10 +125,14 @@ impl GrpcRouter {
                     endpoint: health_check_config.endpoint.clone(),
                     failure_threshold: health_check_config.failure_threshold,
                     success_threshold: health_check_config.success_threshold,
-                });
-                Box::new(worker) as Box<dyn Worker>
                 })
-            .collect();
+                .with_grpc_client(client);
+
+                workers.push(Box::new(worker) as Box<dyn Worker>);
+            } else {
+                warn!("No gRPC client for worker {}, skipping", url);
+            }
+        }
 
         // Initialize policy with workers if needed
         if let Some(cache_aware) = policy
@@ -252,6 +258,11 @@ impl WorkerManagement for GrpcRouter {
     fn remove_worker(&self, _worker_url: &str) {}
 
     fn get_worker_urls(&self) -> Vec<String> {
-        vec![]
+        self.workers
+            .read()
+            .unwrap()
+            .iter()
+            .map(|w| w.url().to_string())
+            .collect()
     }
 }