[router] improve router logs and request id header (#8415)

sgl-router/README.md

@@ -93,6 +93,19 @@ python -m sglang_router.launch_router \
     --prometheus-port 9000
 ```
 
+### Request ID Tracking
+
+Track requests across distributed systems with configurable headers:
+
+```bash
+# Use custom request ID headers
+python -m sglang_router.launch_router \
+    --worker-urls http://localhost:8080 \
+    --request-id-headers x-trace-id x-request-id
+```
+
+Default headers: `x-request-id`, `x-correlation-id`, `x-trace-id`, `request-id`
+
 ## Advanced Features
 
 ### Kubernetes Service Discovery

sgl-router/py_src/sglang_router/launch_router.py

@@ -64,6 +64,8 @@ class RouterArgs:
     # Prometheus configuration
     prometheus_port: Optional[int] = None
     prometheus_host: Optional[str] = None
+    # Request ID headers configuration
+    request_id_headers: Optional[List[str]] = None
 
     @staticmethod
     def add_cli_args(
@@ -255,6 +257,12 @@ class RouterArgs:
             default="127.0.0.1",
             help="Host address to bind the Prometheus metrics server",
         )
+        parser.add_argument(
+            f"--{prefix}request-id-headers",
+            type=str,
+            nargs="*",
+            help="Custom HTTP headers to check for request IDs (e.g., x-request-id x-trace-id). If not specified, uses common defaults.",
+        )
 
     @classmethod
     def from_cli_args(
@@ -313,6 +321,7 @@ class RouterArgs:
             bootstrap_port_annotation="sglang.ai/bootstrap-port",  # Mooncake-specific annotation
             prometheus_port=getattr(args, f"{prefix}prometheus_port", None),
             prometheus_host=getattr(args, f"{prefix}prometheus_host", None),
+            request_id_headers=getattr(args, f"{prefix}request_id_headers", None),
         )
 
     @staticmethod
@@ -481,6 +490,7 @@ def launch_router(args: argparse.Namespace) -> Optional[Router]:
                 if router_args.decode_policy
                 else None
             ),
+            request_id_headers=router_args.request_id_headers,
         )
 
         router.start()

sgl-router/py_src/sglang_router/router.py

@@ -54,6 +54,9 @@ class Router:
             If not specified, uses the main policy. Default: None
         decode_policy: Specific load balancing policy for decode nodes (PD mode only).
             If not specified, uses the main policy. Default: None
+        request_id_headers: List of HTTP headers to check for request IDs. If not specified,
+            uses common defaults: ['x-request-id', 'x-correlation-id', 'x-trace-id', 'request-id'].
+            Example: ['x-my-request-id', 'x-custom-trace-id']. Default: None
     """
 
     def __init__(
@@ -85,6 +88,7 @@ class Router:
         decode_urls: Optional[List[str]] = None,
         prefill_policy: Optional[PolicyType] = None,
         decode_policy: Optional[PolicyType] = None,
+        request_id_headers: Optional[List[str]] = None,
     ):
         if selector is None:
             selector = {}
@@ -121,6 +125,7 @@ class Router:
             decode_urls=decode_urls,
             prefill_policy=prefill_policy,
             decode_policy=decode_policy,
+            request_id_headers=request_id_headers,
         )
 
     def start(self) -> None:

sgl-router/src/config/types.rs

@@ -29,6 +29,8 @@ pub struct RouterConfig {
     pub log_dir: Option<String>,
     /// Log level (None = info)
     pub log_level: Option<String>,
+    /// Custom request ID headers to check (defaults to common headers)
+    pub request_id_headers: Option<Vec<String>>,
 }
 
 /// Routing mode configuration
@@ -207,6 +209,7 @@ impl Default for RouterConfig {
             metrics: None,
             log_dir: None,
             log_level: None,
+            request_id_headers: None,
         }
     }
 }
@@ -312,6 +315,7 @@ mod tests {
             metrics: Some(MetricsConfig::default()),
             log_dir: Some("/var/log".to_string()),
             log_level: Some("debug".to_string()),
+            request_id_headers: None,
         };
 
         let json = serde_json::to_string(&config).unwrap();
@@ -734,6 +738,7 @@ mod tests {
             }),
             log_dir: Some("/var/log/sglang".to_string()),
             log_level: Some("info".to_string()),
+            request_id_headers: None,
         };
 
         assert!(config.mode.is_pd_mode());
@@ -780,6 +785,7 @@ mod tests {
             metrics: Some(MetricsConfig::default()),
             log_dir: None,
             log_level: Some("debug".to_string()),
+            request_id_headers: None,
         };
 
         assert!(!config.mode.is_pd_mode());
@@ -822,6 +828,7 @@ mod tests {
             }),
             log_dir: Some("/opt/logs/sglang".to_string()),
             log_level: Some("trace".to_string()),
+            request_id_headers: None,
         };
 
         assert!(config.has_service_discovery());

sgl-router/src/core/worker.rs

@@ -411,7 +411,7 @@ pub fn start_health_checker(
 
             // Check for shutdown signal
             if shutdown_clone.load(Ordering::Acquire) {
-                tracing::info!("Health checker shutting down");
+                tracing::debug!("Health checker shutting down");
                 break;
             }
 
@@ -439,6 +439,9 @@ pub fn start_health_checker(
                         Err(e) => {
                             if was_healthy {
                                 tracing::warn!("Worker {} health check failed: {}", worker_url, e);
+                            } else {
+                                // Worker was already unhealthy, log at debug level
+                                tracing::debug!("Worker {} remains unhealthy: {}", worker_url, e);
                             }
                         }
                     }

sgl-router/src/lib.rs

@@ -4,6 +4,7 @@ pub mod logging;
 use std::collections::HashMap;
 pub mod core;
 pub mod metrics;
+pub mod middleware;
 pub mod openai_api_types;
 pub mod policies;
 pub mod routers;
@@ -49,6 +50,7 @@ struct Router {
     prometheus_port: Option<u16>,
     prometheus_host: Option<String>,
     request_timeout_secs: u64,
+    request_id_headers: Option<Vec<String>>,
     // PD mode flag
     pd_disaggregation: bool,
     // PD-specific fields (only used when pd_disaggregation is true)
@@ -138,6 +140,7 @@ impl Router {
             metrics,
             log_dir: self.log_dir.clone(),
             log_level: self.log_level.clone(),
+            request_id_headers: self.request_id_headers.clone(),
         })
     }
 }
@@ -170,6 +173,7 @@ impl Router {
         prometheus_port = None,
         prometheus_host = None,
         request_timeout_secs = 600,  // Add configurable request timeout
+        request_id_headers = None,  // Custom request ID headers
         pd_disaggregation = false,  // New flag for PD mode
         prefill_urls = None,
         decode_urls = None,
@@ -201,6 +205,7 @@ impl Router {
         prometheus_port: Option<u16>,
         prometheus_host: Option<String>,
         request_timeout_secs: u64,
+        request_id_headers: Option<Vec<String>>,
         pd_disaggregation: bool,
         prefill_urls: Option<Vec<(String, Option<u16>)>>,
         decode_urls: Option<Vec<String>>,
@@ -232,6 +237,7 @@ impl Router {
             prometheus_port,
             prometheus_host,
             request_timeout_secs,
+            request_id_headers,
             pd_disaggregation,
             prefill_urls,
             decode_urls,
@@ -297,6 +303,7 @@ impl Router {
                 service_discovery_config,
                 prometheus_config,
                 request_timeout_secs: self.request_timeout_secs,
+                request_id_headers: self.request_id_headers.clone(),
             })
             .await
             .map_err(|e| pyo3::exceptions::PyRuntimeError::new_err(e.to_string()))

sgl-router/src/middleware.rs

@@ -0,0 +1,111 @@
+use actix_web::{
+    dev::{forward_ready, Service, ServiceRequest, ServiceResponse, Transform},
+    Error, HttpMessage, HttpRequest,
+};
+use futures_util::future::LocalBoxFuture;
+use std::future::{ready, Ready};
+
+/// Generate OpenAI-compatible request ID based on endpoint
+fn generate_request_id(path: &str) -> String {
+    let prefix = if path.contains("/chat/completions") {
+        "chatcmpl-"
+    } else if path.contains("/completions") {
+        "cmpl-"
+    } else if path.contains("/generate") {
+        "gnt-"
+    } else {
+        "req-"
+    };
+
+    // Generate a random string similar to OpenAI's format
+    let random_part: String = (0..24)
+        .map(|_| {
+            let chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
+            chars
+                .chars()
+                .nth(rand::random::<usize>() % chars.len())
+                .unwrap()
+        })
+        .collect();
+
+    format!("{}{}", prefix, random_part)
+}
+
+/// Extract request ID from request extensions or generate a new one
+pub fn get_request_id(req: &HttpRequest) -> String {
+    req.extensions()
+        .get::<String>()
+        .cloned()
+        .unwrap_or_else(|| generate_request_id(req.path()))
+}
+
+/// Middleware for injecting request ID into request extensions
+pub struct RequestIdMiddleware {
+    headers: Vec<String>,
+}
+
+impl RequestIdMiddleware {
+    pub fn new(headers: Vec<String>) -> Self {
+        Self { headers }
+    }
+}
+
+impl<S, B> Transform<S, ServiceRequest> for RequestIdMiddleware
+where
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S::Future: 'static,
+    B: 'static,
+{
+    type Response = ServiceResponse<B>;
+    type Error = Error;
+    type InitError = ();
+    type Transform = RequestIdMiddlewareService<S>;
+    type Future = Ready<Result<Self::Transform, Self::InitError>>;
+
+    fn new_transform(&self, service: S) -> Self::Future {
+        ready(Ok(RequestIdMiddlewareService {
+            service,
+            headers: self.headers.clone(),
+        }))
+    }
+}
+
+pub struct RequestIdMiddlewareService<S> {
+    service: S,
+    headers: Vec<String>,
+}
+
+impl<S, B> Service<ServiceRequest> for RequestIdMiddlewareService<S>
+where
+    S: Service<ServiceRequest, Response = ServiceResponse<B>, Error = Error>,
+    S::Future: 'static,
+    B: 'static,
+{
+    type Response = ServiceResponse<B>;
+    type Error = Error;
+    type Future = LocalBoxFuture<'static, Result<Self::Response, Self::Error>>;
+
+    forward_ready!(service);
+
+    fn call(&self, req: ServiceRequest) -> Self::Future {
+        // Extract request ID from headers or generate new one
+        let mut request_id = None;
+
+        for header_name in &self.headers {
+            if let Some(header_value) = req.headers().get(header_name) {
+                if let Ok(value) = header_value.to_str() {
+                    request_id = Some(value.to_string());
+                    break;
+                }
+            }
+        }
+
+        let request_id = request_id.unwrap_or_else(|| generate_request_id(req.path()));
+
+        // Insert request ID into request extensions
+        req.extensions_mut().insert(request_id);
+
+        let fut = self.service.call(req);
+        Box::pin(async move { fut.await })
+    }
+}

sgl-router/src/policies/cache_aware.rs

@@ -66,7 +66,7 @@ use crate::tree::Tree;
 use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
-use tracing::{debug, info};
+use tracing::debug;
 
 /// Cache-aware routing policy
 ///
@@ -164,10 +164,8 @@ impl LoadBalancingPolicy for CacheAwarePolicy {
                 .map(|w| (w.url().to_string(), w.load()))
                 .collect();
 
-            info!(
+            debug!(
-                "Load balancing triggered due to workload imbalance:\n\
+                "Load balancing triggered | max: {} | min: {} | workers: {:?}",
-                Max load: {}, Min load: {}\n\
-                Current worker loads: {:?}",
                 max_load, min_load, worker_loads
             );
 

sgl-router/src/routers/pd_router.rs

@@ -5,6 +5,7 @@ use super::pd_types::{api_path, Bootstrap, ChatReqInput, GenerateReqInput, PDRou
 use super::request_adapter::ToPdRequest;
 use crate::core::{HealthChecker, Worker, WorkerFactory, WorkerLoadGuard};
 use crate::metrics::RouterMetrics;
+use crate::middleware::get_request_id;
 use crate::openai_api_types::{ChatCompletionRequest, CompletionRequest, GenerateRequest};
 use crate::policies::LoadBalancingPolicy;
 use crate::tree::Tree;
@@ -16,7 +17,6 @@ use std::collections::HashMap;
 use std::sync::{Arc, Mutex, RwLock};
 use std::time::{Duration, Instant};
 use tracing::{debug, error, info, warn};
-use uuid::Uuid;
 
 #[derive(Debug)]
 pub struct PDRouter {
@@ -307,8 +307,8 @@ impl PDRouter {
         mut typed_req: GenerateReqInput,
         route: &str,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         let start = Instant::now();
-        let _request_id = Uuid::new_v4();
 
         // Get stream flag and return_logprob flag before moving the request
         let is_stream = typed_req.stream;
@@ -328,7 +328,10 @@ impl PDRouter {
         let (prefill, decode) = match self.select_pd_pair(client, request_text).await {
             Ok(pair) => pair,
             Err(e) => {
-                error!("Failed to select PD pair: {}", e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to select PD pair error={}", e
+                );
                 RouterMetrics::record_pd_error("server_selection");
                 return HttpResponse::ServiceUnavailable()
                     .body(format!("No available servers: {}", e));
@@ -337,15 +340,17 @@ impl PDRouter {
 
         // Log routing decision
         info!(
-            "PD routing: {} -> prefill={}, decode={}",
+            request_id = %request_id,
-            route,
+            "PD routing decision route={} prefill_url={} decode_url={}",
-            prefill.url(),
+            route, prefill.url(), decode.url()
-            decode.url()
         );
 
         // Add bootstrap info using the trait method
         if let Err(e) = typed_req.add_bootstrap_info(prefill.as_ref()) {
-            error!("Failed to add bootstrap info: {}", e);
+            error!(
+                request_id = %request_id,
+                "Failed to add bootstrap info error={}", e
+            );
             RouterMetrics::record_pd_error("bootstrap_injection");
             return HttpResponse::InternalServerError()
                 .body(format!("Bootstrap injection failed: {}", e));
@@ -355,7 +360,10 @@ impl PDRouter {
         let json_with_bootstrap = match serde_json::to_value(&typed_req) {
             Ok(json) => json,
             Err(e) => {
-                error!("Failed to serialize request: {}", e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to serialize request error={}", e
+                );
                 return HttpResponse::InternalServerError().body("Failed to serialize request");
             }
         };
@@ -383,6 +391,7 @@ impl PDRouter {
         mut typed_req: ChatReqInput,
         route: &str,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         let start = Instant::now();
 
         // Get stream flag and return_logprob flag before moving the request
@@ -406,7 +415,10 @@ impl PDRouter {
         let (prefill, decode) = match self.select_pd_pair(client, request_text).await {
             Ok(pair) => pair,
             Err(e) => {
-                error!("Failed to select PD pair: {}", e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to select PD pair error={}", e
+                );
                 RouterMetrics::record_pd_error("server_selection");
                 return HttpResponse::ServiceUnavailable()
                     .body(format!("No available servers: {}", e));
@@ -415,15 +427,17 @@ impl PDRouter {
 
         // Log routing decision
         info!(
-            "PD routing: {} -> prefill={}, decode={}",
+            request_id = %request_id,
-            route,
+            "PD routing decision route={} prefill_url={} decode_url={}",
-            prefill.url(),
+            route, prefill.url(), decode.url()
-            decode.url()
         );
 
         // Add bootstrap info using the trait method
         if let Err(e) = typed_req.add_bootstrap_info(prefill.as_ref()) {
-            error!("Failed to add bootstrap info: {}", e);
+            error!(
+                request_id = %request_id,
+                "Failed to add bootstrap info error={}", e
+            );
             RouterMetrics::record_pd_error("bootstrap_injection");
             return HttpResponse::InternalServerError()
                 .body(format!("Bootstrap injection failed: {}", e));
@@ -433,7 +447,10 @@ impl PDRouter {
         let json_with_bootstrap = match serde_json::to_value(&typed_req) {
             Ok(json) => json,
             Err(e) => {
-                error!("Failed to serialize request: {}", e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to serialize request error={}", e
+                );
                 return HttpResponse::InternalServerError().body("Failed to serialize request");
             }
         };
@@ -461,6 +478,7 @@ impl PDRouter {
         mut typed_req: CompletionRequest,
         route: &str,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         let start = Instant::now();
 
         // Get stream flag and return_logprob flag before moving the request
@@ -477,7 +495,10 @@ impl PDRouter {
         let (prefill, decode) = match self.select_pd_pair(client, request_text).await {
             Ok(pair) => pair,
             Err(e) => {
-                error!("Failed to select PD pair: {}", e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to select PD pair error={}", e
+                );
                 RouterMetrics::record_pd_error("server_selection");
                 return HttpResponse::ServiceUnavailable()
                     .body(format!("No available servers: {}", e));
@@ -486,15 +507,17 @@ impl PDRouter {
 
         // Log routing decision
         info!(
-            "PD routing: {} -> prefill={}, decode={}",
+            request_id = %request_id,
-            route,
+            "PD routing decision route={} prefill_url={} decode_url={}",
-            prefill.url(),
+            route, prefill.url(), decode.url()
-            decode.url()
         );
 
         // Add bootstrap info using the trait method
         if let Err(e) = typed_req.add_bootstrap_info(prefill.as_ref()) {
-            error!("Failed to add bootstrap info: {}", e);
+            error!(
+                request_id = %request_id,
+                "Failed to add bootstrap info error={}", e
+            );
             RouterMetrics::record_pd_error("bootstrap_injection");
             return HttpResponse::InternalServerError()
                 .body(format!("Bootstrap injection failed: {}", e));
@@ -504,7 +527,10 @@ impl PDRouter {
         let json_with_bootstrap = match serde_json::to_value(&typed_req) {
             Ok(json) => json,
             Err(e) => {
-                error!("Failed to serialize request: {}", e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to serialize request error={}", e
+                );
                 return HttpResponse::InternalServerError().body("Failed to serialize request");
             }
         };
@@ -538,6 +564,7 @@ impl PDRouter {
         return_logprob: bool,
         start_time: Instant,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         // Update load tracking for both workers
         let _guard = WorkerLoadGuard::new_multi(vec![prefill, decode]);
 
@@ -578,9 +605,9 @@ impl PDRouter {
                 if !status.is_success() {
                     RouterMetrics::record_pd_decode_error(decode.url());
                     error!(
-                        "Decode server {} returned error status: {}",
+                        request_id = %request_id,
-                        decode.url(),
+                        "Decode server returned error status decode_url={} status={}",
-                        status
+                        decode.url(), status
                     );
 
                     // Return the error response from decode server
@@ -598,9 +625,9 @@ impl PDRouter {
                 // Log prefill errors for debugging
                 if let Err(e) = &prefill_result {
                     error!(
-                        "Prefill server {} failed (non-critical): {}",
+                        request_id = %request_id,
-                        prefill.url(),
+                        "Prefill server failed (non-critical) prefill_url={} error={}",
-                        e
+                        prefill.url(), e
                     );
                     RouterMetrics::record_pd_prefill_error(prefill.url());
                 }
@@ -684,7 +711,12 @@ impl PDRouter {
                 }
             }
             Err(e) => {
-                error!("Decode request failed: {}", e);
+                error!(
+                    request_id = %request_id,
+                    decode_url = %decode.url(),
+                    error = %e,
+                    "Decode request failed"
+                );
                 RouterMetrics::record_pd_decode_error(decode.url());
                 HttpResponse::BadGateway().body(format!("Decode server error: {}", e))
             }

sgl-router/src/routers/router.rs

@@ -1,5 +1,6 @@
 use crate::core::{HealthChecker, Worker, WorkerFactory};
 use crate::metrics::RouterMetrics;
+use crate::middleware::get_request_id;
 use crate::policies::LoadBalancingPolicy;
 use actix_web::http::header::{HeaderValue, CONTENT_TYPE};
 use actix_web::{HttpRequest, HttpResponse};
@@ -134,32 +135,26 @@ impl Router {
                 match sync_client.get(&format!("{}/health", url)).send() {
                     Ok(res) => {
                         if !res.status().is_success() {
-                            let msg = format!(
-                                "Worker heatlh check is pending with status {}",
-                                res.status()
-                            );
-                            info!("{}", msg);
                             all_healthy = false;
-                            unhealthy_workers.push((url, msg));
+                            unhealthy_workers.push((url, format!("status: {}", res.status())));
                         }
                     }
                     Err(_) => {
-                        let msg = format!("Worker is not ready yet");
-                        info!("{}", msg);
                         all_healthy = false;
-                        unhealthy_workers.push((url, msg));
+                        unhealthy_workers.push((url, "not ready".to_string()));
                     }
                 }
             }
 
             if all_healthy {
-                info!("All workers are healthy");
+                info!("All {} workers are healthy", worker_urls.len());
                 return Ok(());
             } else {
-                info!("Initializing workers:");
+                debug!(
-                for (url, reason) in &unhealthy_workers {
+                    "Waiting for {} workers to become healthy ({} unhealthy)",
-                    info!("  {} - {}", url, reason);
+                    worker_urls.len(),
-                }
+                    unhealthy_workers.len()
+                );
                 thread::sleep(Duration::from_secs(interval_secs));
             }
         }
@@ -181,6 +176,7 @@ impl Router {
         route: &str,
         req: &HttpRequest,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         let start = Instant::now();
         let mut request_builder = client.get(format!("{}{}", worker_url, route));
 
@@ -202,14 +198,32 @@ impl Router {
 
                 match res.bytes().await {
                     Ok(body) => HttpResponse::build(status).body(body.to_vec()),
-                    Err(e) => HttpResponse::InternalServerError()
+                    Err(e) => {
-                        .body(format!("Failed to read response body: {}", e)),
+                        error!(
+                            request_id = %request_id,
+                            worker_url = %worker_url,
+                            route = %route,
+                            error = %e,
+                            "Failed to read response body"
+                        );
+                        HttpResponse::InternalServerError()
+                            .body(format!("Failed to read response body: {}", e))
+                    }
                 }
             }
-            Err(e) => HttpResponse::InternalServerError().body(format!(
+            Err(e) => {
-                "Failed to send request to worker {}: {}",
+                error!(
-                worker_url, e
+                    request_id = %request_id,
-            )),
+                    worker_url = %worker_url,
+                    route = %route,
+                    error = %e,
+                    "Failed to send request to worker"
+                );
+                HttpResponse::InternalServerError().body(format!(
+                    "Failed to send request to worker {}: {}",
+                    worker_url, e
+                ))
+            }
         };
 
         // Record request metrics
@@ -231,6 +245,7 @@ impl Router {
         route: &str,
         req: &HttpRequest,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         const MAX_REQUEST_RETRIES: u32 = 3;
         const MAX_TOTAL_RETRIES: u32 = 6;
         let mut total_retries = 0;
@@ -260,17 +275,23 @@ impl Router {
                         }
 
                         warn!(
-                            "Request to {} failed (attempt {}/{})",
+                            request_id = %request_id,
-                            worker_url,
+                            route = %route,
-                            request_retries + 1,
+                            worker_url = %worker_url,
-                            MAX_REQUEST_RETRIES
+                            attempt = request_retries + 1,
+                            max_attempts = MAX_REQUEST_RETRIES,
+                            "Request failed"
                         );
 
                         request_retries += 1;
                         total_retries += 1;
 
                         if request_retries == MAX_REQUEST_RETRIES {
-                            warn!("Removing failed worker: {}", worker_url);
+                            warn!(
+                                request_id = %request_id,
+                                worker_url = %worker_url,
+                                "Removing failed worker"
+                            );
                             self.remove_worker(&worker_url);
                             break;
                         }
@@ -293,6 +314,7 @@ impl Router {
         typed_req: &T,
         route: &str,
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         // Handle retries like the original implementation
         let start = Instant::now();
         const MAX_REQUEST_RETRIES: u32 = 3;
@@ -357,17 +379,19 @@ impl Router {
                 }
 
                 warn!(
-                    "Generate request to {} failed (attempt {}/{})",
+                    request_id = %request_id,
-                    worker_url,
+                    "Generate request failed route={} worker_url={} attempt={} max_attempts={}",
-                    request_retries + 1,
+                    route, worker_url, request_retries + 1, MAX_REQUEST_RETRIES
-                    MAX_REQUEST_RETRIES
                 );
 
                 request_retries += 1;
                 total_retries += 1;
 
                 if request_retries == MAX_REQUEST_RETRIES {
-                    warn!("Removing failed worker: {}", worker_url);
+                    warn!(
+                        request_id = %request_id,
+                        "Removing failed worker after typed request failures worker_url={}", worker_url
+                    );
                     self.remove_worker(&worker_url);
                     break;
                 }
@@ -402,13 +426,9 @@ impl Router {
         is_stream: bool,
         load_incremented: bool, // Whether load was incremented for this request
     ) -> HttpResponse {
+        let request_id = get_request_id(req);
         let start = Instant::now();
 
-        // Debug: Log what we're sending
-        if let Ok(json_str) = serde_json::to_string_pretty(typed_req) {
-            debug!("Sending request to {}: {}", route, json_str);
-        }
-
         let mut request_builder = client
             .post(format!("{}{}", worker_url, route))
             .json(typed_req); // Use json() directly with typed request
@@ -424,7 +444,11 @@ impl Router {
         let res = match request_builder.send().await {
             Ok(res) => res,
             Err(e) => {
-                error!("Failed to send request to {}: {}", worker_url, e);
+                error!(
+                    request_id = %request_id,
+                    "Failed to send typed request worker_url={} route={} error={}",
+                    worker_url, route, e
+                );
 
                 // Decrement load on error if it was incremented
                 if load_incremented {
@@ -497,7 +521,6 @@ impl Router {
                                                 &worker_url,
                                                 worker.load(),
                                             );
-                                            debug!("Streaming is done!!")
                                         }
                                     }
                                 }
@@ -536,7 +559,6 @@ impl Router {
             match client.get(&format!("{}/health", worker_url)).send().await {
                 Ok(res) => {
                     if res.status().is_success() {
-                        info!("Worker {} health check passed", worker_url);
                         let mut workers_guard = self.workers.write().unwrap();
                         if workers_guard.iter().any(|w| w.url() == worker_url) {
                             return Err(format!("Worker {} already exists", worker_url));
@@ -560,8 +582,8 @@ impl Router {
 
                         return Ok(format!("Successfully added worker: {}", worker_url));
                     } else {
-                        info!(
+                        debug!(
-                            "Worker {} health check is pending with status: {}.",
+                            "Worker {} health check pending - status: {}",
                             worker_url,
                             res.status()
                         );
@@ -576,10 +598,7 @@ impl Router {
                     }
                 }
                 Err(e) => {
-                    info!(
+                    debug!("Worker {} health check pending - error: {}", worker_url, e);
-                        "Worker {} health check is pending with error: {}",
-                        worker_url, e
-                    );
 
                     // if the url does not have http or https prefix, warn users
                     if !worker_url.starts_with("http://") && !worker_url.starts_with("https://") {
@@ -611,7 +630,6 @@ impl Router {
             .downcast_ref::<crate::policies::CacheAwarePolicy>()
         {
             cache_aware.remove_worker(worker_url);
-            info!("Removed worker from tree: {}", worker_url);
         }
     }
 
@@ -675,7 +693,6 @@ impl Router {
             for url in &worker_urls {
                 if let Some(load) = Self::get_worker_load_static(&client, url).await {
                     loads.insert(url.clone(), load);
-                    debug!("Worker {} load: {}", url, load);
                 }
             }
 

sgl-router/src/server.rs

@@ -1,6 +1,7 @@
 use crate::config::RouterConfig;
 use crate::logging::{self, LoggingConfig};
 use crate::metrics::{self, PrometheusConfig};
+use crate::middleware::{get_request_id, RequestIdMiddleware};
 use crate::openai_api_types::{ChatCompletionRequest, CompletionRequest, GenerateRequest};
 use crate::routers::{RouterFactory, RouterTrait};
 use crate::service_discovery::{start_service_discovery, ServiceDiscoveryConfig};
@@ -46,13 +47,13 @@ async fn sink_handler(_req: HttpRequest, mut payload: web::Payload) -> Result<Ht
 }
 
 // Custom error handler for JSON payload errors.
-fn json_error_handler(err: error::JsonPayloadError, _req: &HttpRequest) -> Error {
+fn json_error_handler(err: error::JsonPayloadError, req: &HttpRequest) -> Error {
-    error!("JSON payload error: {:?}", err);
+    let request_id = get_request_id(req);
     match &err {
         error::JsonPayloadError::OverflowKnownLength { length, limit } => {
             error!(
-                "Payload too large: {} bytes exceeds limit of {} bytes",
+                request_id = %request_id,
-                length, limit
+                "Payload too large length={} limit={}", length, limit
             );
             error::ErrorPayloadTooLarge(format!(
                 "Payload too large: {} bytes exceeds limit of {} bytes",
@@ -60,10 +61,19 @@ fn json_error_handler(err: error::JsonPayloadError, _req: &HttpRequest) -> Error
             ))
         }
         error::JsonPayloadError::Overflow { limit } => {
-            error!("Payload overflow: exceeds limit of {} bytes", limit);
+            error!(
+                request_id = %request_id,
+                "Payload overflow limit={}", limit
+            );
             error::ErrorPayloadTooLarge(format!("Payload exceeds limit of {} bytes", limit))
         }
-        _ => error::ErrorBadRequest(format!("Invalid JSON payload: {}", err)),
+        _ => {
+            error!(
+                request_id = %request_id,
+                "Invalid JSON payload error={}", err
+            );
+            error::ErrorBadRequest(format!("Invalid JSON payload: {}", err))
+        }
     }
 }
 
@@ -108,8 +118,20 @@ async fn generate(
     body: web::Json<GenerateRequest>,
     state: web::Data<AppState>,
 ) -> Result<HttpResponse, Error> {
-    let json_body = serde_json::to_value(body.into_inner())
+    let request_id = get_request_id(&req);
-        .map_err(|e| error::ErrorBadRequest(format!("Invalid JSON: {}", e)))?;
+    info!(
+        request_id = %request_id,
+        "Received generate request method=\"POST\" path=\"/generate\""
+    );
+
+    let json_body = serde_json::to_value(body.into_inner()).map_err(|e| {
+        error!(
+            request_id = %request_id,
+            "Failed to parse generate request body error={}", e
+        );
+        error::ErrorBadRequest(format!("Invalid JSON: {}", e))
+    })?;
+
     Ok(state
         .router
         .route_generate(&state.client, &req, json_body)
@@ -122,8 +144,20 @@ async fn v1_chat_completions(
     body: web::Json<ChatCompletionRequest>,
     state: web::Data<AppState>,
 ) -> Result<HttpResponse, Error> {
-    let json_body = serde_json::to_value(body.into_inner())
+    let request_id = get_request_id(&req);
-        .map_err(|e| error::ErrorBadRequest(format!("Invalid JSON: {}", e)))?;
+    info!(
+        request_id = %request_id,
+        "Received chat completion request method=\"POST\" path=\"/v1/chat/completions\""
+    );
+
+    let json_body = serde_json::to_value(body.into_inner()).map_err(|e| {
+        error!(
+            request_id = %request_id,
+            "Failed to parse chat completion request body error={}", e
+        );
+        error::ErrorBadRequest(format!("Invalid JSON: {}", e))
+    })?;
+
     Ok(state
         .router
         .route_chat(&state.client, &req, json_body)
@@ -136,8 +170,20 @@ async fn v1_completions(
     body: web::Json<CompletionRequest>,
     state: web::Data<AppState>,
 ) -> Result<HttpResponse, Error> {
-    let json_body = serde_json::to_value(body.into_inner())
+    let request_id = get_request_id(&req);
-        .map_err(|e| error::ErrorBadRequest(format!("Invalid JSON: {}", e)))?;
+    info!(
+        request_id = %request_id,
+        "Received completion request method=\"POST\" path=\"/v1/completions\""
+    );
+
+    let json_body = serde_json::to_value(body.into_inner()).map_err(|e| {
+        error!(
+            request_id = %request_id,
+            "Failed to parse completion request body error={}", e
+        );
+        error::ErrorBadRequest(format!("Invalid JSON: {}", e))
+    })?;
+
     Ok(state
         .router
         .route_completion(&state.client, &req, json_body)
@@ -146,20 +192,48 @@ async fn v1_completions(
 
 #[post("/add_worker")]
 async fn add_worker(
+    req: HttpRequest,
     query: web::Query<HashMap<String, String>>,
     data: web::Data<AppState>,
 ) -> impl Responder {
+    let request_id = get_request_id(&req);
+
     let worker_url = match query.get("url") {
         Some(url) => url.to_string(),
         None => {
+            warn!(
+                request_id = %request_id,
+                "Add worker request missing URL parameter"
+            );
             return HttpResponse::BadRequest()
-                .body("Worker URL required. Provide 'url' query parameter")
+                .body("Worker URL required. Provide 'url' query parameter");
         }
     };
 
+    info!(
+        request_id = %request_id,
+        worker_url = %worker_url,
+        "Adding worker"
+    );
+
     match data.router.add_worker(&worker_url).await {
-        Ok(message) => HttpResponse::Ok().body(message),
+        Ok(message) => {
-        Err(error) => HttpResponse::BadRequest().body(error),
+            info!(
+                request_id = %request_id,
+                worker_url = %worker_url,
+                "Successfully added worker"
+            );
+            HttpResponse::Ok().body(message)
+        }
+        Err(error) => {
+            error!(
+                request_id = %request_id,
+                worker_url = %worker_url,
+                error = %error,
+                "Failed to add worker"
+            );
+            HttpResponse::BadRequest().body(error)
+        }
     }
 }
 
@@ -171,13 +245,29 @@ async fn list_workers(data: web::Data<AppState>) -> impl Responder {
 
 #[post("/remove_worker")]
 async fn remove_worker(
+    req: HttpRequest,
     query: web::Query<HashMap<String, String>>,
     data: web::Data<AppState>,
 ) -> impl Responder {
+    let request_id = get_request_id(&req);
+
     let worker_url = match query.get("url") {
         Some(url) => url.to_string(),
-        None => return HttpResponse::BadRequest().finish(),
+        None => {
+            warn!(
+                request_id = %request_id,
+                "Remove worker request missing URL parameter"
+            );
+            return HttpResponse::BadRequest().finish();
+        }
     };
+
+    info!(
+        request_id = %request_id,
+        worker_url = %worker_url,
+        "Removing worker"
+    );
+
     data.router.remove_worker(&worker_url);
     HttpResponse::Ok().body(format!("Successfully removed worker: {}", worker_url))
 }
@@ -202,6 +292,7 @@ pub struct ServerConfig {
     pub service_discovery_config: Option<ServiceDiscoveryConfig>,
     pub prometheus_config: Option<PrometheusConfig>,
     pub request_timeout_secs: u64,
+    pub request_id_headers: Option<Vec<String>>,
 }
 
 pub async fn startup(config: ServerConfig) -> std::io::Result<()> {
@@ -233,31 +324,18 @@ pub async fn startup(config: ServerConfig) -> std::io::Result<()> {
 
     // Initialize prometheus metrics exporter
     if let Some(prometheus_config) = config.prometheus_config {
-        info!(
-            "🚧 Initializing Prometheus metrics on {}:{}",
-            prometheus_config.host, prometheus_config.port
-        );
         metrics::start_prometheus(prometheus_config);
-    } else {
-        info!("🚧 Prometheus metrics disabled");
     }
 
-    info!("🚧 Initializing router on {}:{}", config.host, config.port);
-    info!("🚧 Router mode: {:?}", config.router_config.mode);
-    info!("🚧 Policy: {:?}", config.router_config.policy);
     info!(
-        "🚧 Max payload size: {} MB",
+        "Starting router on {}:{} | mode: {:?} | policy: {:?} | max_payload: {}MB",
+        config.host,
+        config.port,
+        config.router_config.mode,
+        config.router_config.policy,
         config.max_payload_size / (1024 * 1024)
     );
 
-    // Log service discovery status
-    if let Some(service_discovery_config) = &config.service_discovery_config {
-        info!("🚧 Service discovery enabled");
-        info!("🚧 Selector: {:?}", service_discovery_config.selector);
-    } else {
-        info!("🚧 Service discovery disabled");
-    }
-
     let client = Client::builder()
         .pool_idle_timeout(Some(Duration::from_secs(50)))
         .timeout(Duration::from_secs(config.request_timeout_secs)) // Use configurable timeout
@@ -272,11 +350,9 @@ pub async fn startup(config: ServerConfig) -> std::io::Result<()> {
     // Start the service discovery if enabled
     if let Some(service_discovery_config) = config.service_discovery_config {
         if service_discovery_config.enabled {
-            info!("🚧 Initializing Kubernetes service discovery");
-            // Pass the Arc<Router> directly
             match start_service_discovery(service_discovery_config, router_arc).await {
                 Ok(handle) => {
-                    info!("✅ Service discovery started successfully");
+                    info!("Service discovery started");
                     // Spawn a task to handle the service discovery thread
                     spawn(async move {
                         if let Err(e) = handle.await {
@@ -292,14 +368,26 @@ pub async fn startup(config: ServerConfig) -> std::io::Result<()> {
         }
     }
 
-    info!("✅ Serving router on {}:{}", config.host, config.port);
     info!(
-        "✅ Serving workers on {:?}",
+        "Router ready | workers: {:?}",
         app_state.router.get_worker_urls()
     );
 
+    // Configure request ID headers
+    let request_id_headers = config.request_id_headers.clone().unwrap_or_else(|| {
+        vec![
+            "x-request-id".to_string(),
+            "x-correlation-id".to_string(),
+            "x-trace-id".to_string(),
+            "request-id".to_string(),
+        ]
+    });
+
     HttpServer::new(move || {
+        let request_id_middleware = RequestIdMiddleware::new(request_id_headers.clone());
+
         App::new()
+            .wrap(request_id_middleware)
             .app_data(app_state.clone())
             .app_data(
                 web::JsonConfig::default()

sgl-router/src/service_discovery.rs

@@ -209,7 +209,7 @@ pub async fn start_service_discovery(
             .join(",");
 
         info!(
-            "Starting Kubernetes service discovery in PD mode with prefill_selector: '{}', decode_selector: '{}'",
+            "Starting K8s service discovery | PD mode | prefill: '{}' | decode: '{}'",
             prefill_selector, decode_selector
         );
     } else {
@@ -221,7 +221,7 @@ pub async fn start_service_discovery(
             .join(",");
 
         info!(
-            "Starting Kubernetes service discovery with selector: '{}'",
+            "Starting K8s service discovery | selector: '{}'",
             label_selector
         );
     }
@@ -238,7 +238,7 @@ pub async fn start_service_discovery(
             Api::all(client)
         };
 
-        info!("Kubernetes service discovery initialized successfully");
+        debug!("K8s service discovery initialized");
 
         // Create Arcs for configuration data
         let config_arc = Arc::new(config.clone());
@@ -375,7 +375,7 @@ async fn handle_pod_event(
 
         if should_add {
             info!(
-                "Healthy pod found: {} (type: {:?}). Adding worker: {}",
+                "Adding pod: {} | type: {:?} | url: {}",
                 pod_info.name, pod_info.pod_type, worker_url
             );
 
@@ -409,8 +409,8 @@ async fn handle_pod_event(
             };
 
             match result {
-                Ok(msg) => {
+                Ok(_) => {
-                    info!("Successfully added worker: {}", msg);
+                    debug!("Worker added: {}", worker_url);
                 }
                 Err(e) => {
                     error!("Failed to add worker {} to router: {}", worker_url, e);
@@ -446,7 +446,7 @@ async fn handle_pod_deletion(
 
     if was_tracked {
         info!(
-            "Pod deleted: {} (type: {:?}). Removing worker: {}",
+            "Removing pod: {} | type: {:?} | url: {}",
             pod_info.name, pod_info.pod_type, worker_url
         );
 

sgl-router/tests/api_endpoints_test.rs

@@ -35,6 +35,7 @@ impl TestContext {
             metrics: None,
             log_dir: None,
             log_level: None,
+            request_id_headers: None,
         };
 
         Self::new_with_config(config, worker_configs).await
@@ -953,6 +954,7 @@ mod error_tests {
                 metrics: None,
                 log_dir: None,
                 log_level: None,
+                request_id_headers: None,
             };
 
             let ctx = TestContext::new_with_config(

sgl-router/tests/common/mod.rs

@@ -20,6 +20,7 @@ pub fn create_test_config(worker_urls: Vec<String>) -> RouterConfig {
         metrics: None,
         log_dir: None,
         log_level: None,
+        request_id_headers: None,
     }
 }
 
@@ -40,6 +41,7 @@ pub fn create_test_config_no_workers() -> RouterConfig {
         metrics: None,
         log_dir: None,
         log_level: None,
+        request_id_headers: None,
     }
 }
 

sgl-router/tests/request_formats_test.rs

@@ -46,6 +46,7 @@ impl RequestTestContext {
             metrics: None,
             log_dir: None,
             log_level: None,
+            request_id_headers: None,
         };
 
         let client = Client::builder()

sgl-router/tests/streaming_tests.rs

@@ -50,6 +50,7 @@ impl StreamingTestContext {
             metrics: None,
             log_dir: None,
             log_level: None,
+            request_id_headers: None,
         };
 
         let client = Client::builder()

sgl-router/tests/test_pd_routing.rs

@@ -173,6 +173,7 @@ mod test_pd_routing {
                 metrics: None,
                 log_dir: None,
                 log_level: None,
+                request_id_headers: None,
             };
 
             // Router creation will fail due to health checks, but config should be valid