[router] disable rate limiter by default (#11435)

sgl-router/py_src/sglang_router/router_args.py

@@ -54,8 +54,8 @@ class RouterArgs:
     request_id_headers: Optional[List[str]] = None
     # Request timeout in seconds
     request_timeout_secs: int = 1800
-    # Max concurrent requests for rate limiting
-    max_concurrent_requests: int = 256
+    # Max concurrent requests for rate limiting (-1 to disable)
+    max_concurrent_requests: int = -1
     # Queue size for pending requests when max concurrent limit reached
     queue_size: int = 100
     # Maximum time (in seconds) a request can wait in queue before timing out
@@ -409,7 +409,7 @@ class RouterArgs:
             f"--{prefix}max-concurrent-requests",
             type=int,
             default=RouterArgs.max_concurrent_requests,
-            help="Maximum number of concurrent requests allowed (for rate limiting)",
+            help="Maximum number of concurrent requests allowed (for rate limiting). Set to -1 to disable rate limiting.",
         )
         parser.add_argument(
             f"--{prefix}queue-size",

sgl-router/src/config/types.rs

@@ -38,14 +38,14 @@ pub struct RouterConfig {
     pub log_level: Option<String>,
     /// Custom request ID headers to check (defaults to common headers)
     pub request_id_headers: Option<Vec<String>>,
-    /// Maximum concurrent requests allowed (for rate limiting)
-    pub max_concurrent_requests: usize,
+    /// Maximum concurrent requests allowed (for rate limiting). Set to -1 to disable rate limiting.
+    pub max_concurrent_requests: i32,
     /// Queue size for pending requests when max concurrent limit reached (0 = no queue, return 429 immediately)
     pub queue_size: usize,
     /// Maximum time (in seconds) a request can wait in queue before timing out
     pub queue_timeout_secs: u64,
     /// Token bucket refill rate (tokens per second). If not set, defaults to max_concurrent_requests
-    pub rate_limit_tokens_per_second: Option<usize>,
+    pub rate_limit_tokens_per_second: Option<i32>,
     /// CORS allowed origins
     pub cors_allowed_origins: Vec<String>,
     /// Retry configuration
@@ -436,7 +436,7 @@ impl Default for RouterConfig {
             log_dir: None,
             log_level: None,
             request_id_headers: None,
-            max_concurrent_requests: 256,
+            max_concurrent_requests: -1,
             queue_size: 100,
             queue_timeout_secs: 60,
             rate_limit_tokens_per_second: None,

sgl-router/src/lib.rs

@@ -65,7 +65,7 @@ struct Router {
     decode_urls: Option<Vec<String>>,
     prefill_policy: Option<PolicyType>,
     decode_policy: Option<PolicyType>,
-    max_concurrent_requests: usize,
+    max_concurrent_requests: i32,
     cors_allowed_origins: Vec<String>,
     retry_max_retries: u32,
     retry_initial_backoff_ms: u64,
@@ -86,7 +86,7 @@ struct Router {
     enable_igw: bool,
     queue_size: usize,
     queue_timeout_secs: u64,
-    rate_limit_tokens_per_second: Option<usize>,
+    rate_limit_tokens_per_second: Option<i32>,
     connection_mode: config::ConnectionMode,
     model_path: Option<String>,
     tokenizer_path: Option<String>,
@@ -260,7 +260,7 @@ impl Router {
         decode_urls = None,
         prefill_policy = None,
         decode_policy = None,
-        max_concurrent_requests = 256,
+        max_concurrent_requests = -1,
         cors_allowed_origins = vec![],
         retry_max_retries = 5,
         retry_initial_backoff_ms = 50,
@@ -321,7 +321,7 @@ impl Router {
         decode_urls: Option<Vec<String>>,
         prefill_policy: Option<PolicyType>,
         decode_policy: Option<PolicyType>,
-        max_concurrent_requests: usize,
+        max_concurrent_requests: i32,
         cors_allowed_origins: Vec<String>,
         retry_max_retries: u32,
         retry_initial_backoff_ms: u64,
@@ -342,7 +342,7 @@ impl Router {
         enable_igw: bool,
         queue_size: usize,
         queue_timeout_secs: u64,
-        rate_limit_tokens_per_second: Option<usize>,
+        rate_limit_tokens_per_second: Option<i32>,
         model_path: Option<String>,
         tokenizer_path: Option<String>,
         reasoning_parser: Option<String>,

sgl-router/src/main.rs

@@ -192,8 +192,8 @@ struct CliArgs {
     #[arg(long, default_value_t = 1800)]
     request_timeout_secs: u64,
 
-    #[arg(long, default_value_t = 256)]
-    max_concurrent_requests: usize,
+    #[arg(long, default_value_t = -1)]
+    max_concurrent_requests: i32,
 
     #[arg(long, num_args = 0..)]
     cors_allowed_origins: Vec<String>,

sgl-router/src/middleware.rs

@@ -424,22 +424,23 @@ pub struct ConcurrencyLimiter {
 impl ConcurrencyLimiter {
     /// Create new concurrency limiter with optional queue
     pub fn new(
-        token_bucket: Arc<TokenBucket>,
+        token_bucket: Option<Arc<TokenBucket>>,
         queue_size: usize,
         queue_timeout: Duration,
     ) -> (Self, Option<QueueProcessor>) {
-        if queue_size > 0 {
-            let (queue_tx, queue_rx) = mpsc::channel(queue_size);
-            let processor = QueueProcessor::new(token_bucket, queue_rx, queue_timeout);
-
+        match (token_bucket, queue_size) {
+            (None, _) => (Self { queue_tx: None }, None),
+            (Some(bucket), size) if size > 0 => {
+                let (queue_tx, queue_rx) = mpsc::channel(size);
+                let processor = QueueProcessor::new(bucket, queue_rx, queue_timeout);
                 (
                     Self {
                         queue_tx: Some(queue_tx),
                     },
                     Some(processor),
                 )
-        } else {
-            (Self { queue_tx: None }, None)
+            }
+            (Some(_), _) => (Self { queue_tx: None }, None),
         }
     }
 }
@@ -450,12 +451,19 @@ pub async fn concurrency_limit_middleware(
     request: Request<Body>,
     next: Next,
 ) -> Response {
+    let token_bucket = match &app_state.context.rate_limiter {
+        Some(bucket) => bucket.clone(),
+        None => {
+            // Rate limiting disabled, pass through immediately
+            return next.run(request).await;
+        }
+    };
+
     // Static counter for embeddings queue size
     static EMBEDDINGS_QUEUE_SIZE: AtomicU64 = AtomicU64::new(0);
 
     // Identify if this is an embeddings request based on path
     let is_embeddings = request.uri().path().contains("/v1/embeddings");
-    let token_bucket = app_state.context.rate_limiter.clone();
 
     // Try to acquire token immediately
     if token_bucket.try_acquire(1.0).await.is_ok() {

sgl-router/src/server.rs

@@ -48,7 +48,7 @@ use tracing::{error, info, warn, Level};
 pub struct AppContext {
     pub client: Client,
     pub router_config: RouterConfig,
-    pub rate_limiter: Arc<TokenBucket>,
+    pub rate_limiter: Option<Arc<TokenBucket>>,
     pub tokenizer: Option<Arc<dyn Tokenizer>>,
     pub reasoning_parser_factory: Option<ReasoningParserFactory>,
     pub tool_parser_factory: Option<ToolParserFactory>,
@@ -67,11 +67,20 @@ impl AppContext {
     pub fn new(
         router_config: RouterConfig,
         client: Client,
-        max_concurrent_requests: usize,
-        rate_limit_tokens_per_second: Option<usize>,
+        max_concurrent_requests: i32,
+        rate_limit_tokens_per_second: Option<i32>,
     ) -> Result<Self, String> {
-        let rate_limit_tokens = rate_limit_tokens_per_second.unwrap_or(max_concurrent_requests);
-        let rate_limiter = Arc::new(TokenBucket::new(max_concurrent_requests, rate_limit_tokens));
+        let rate_limiter = match max_concurrent_requests {
+            n if n <= 0 => None,
+            n => {
+                let rate_limit_tokens =
+                    rate_limit_tokens_per_second.filter(|&t| t > 0).unwrap_or(n);
+                Some(Arc::new(TokenBucket::new(
+                    n as usize,
+                    rate_limit_tokens as usize,
+                )))
+            }
+        };
 
         let (tokenizer, reasoning_parser_factory, tool_parser_factory) =
             if router_config.connection_mode == ConnectionMode::Grpc {
@@ -916,13 +925,25 @@ pub async fn startup(config: ServerConfig) -> Result<(), Box<dyn std::error::Err
         Duration::from_secs(config.router_config.queue_timeout_secs),
     );
 
-    if let Some(processor) = processor {
-        spawn(processor.run());
+    if app_context.rate_limiter.is_none() {
+        info!("Rate limiting is disabled (max_concurrent_requests = -1)");
+    }
+
+    match processor {
+        Some(proc) => {
+            spawn(proc.run());
             info!(
-            "Started request queue with size: {}, timeout: {}s",
+                "Started request queue (size: {}, timeout: {}s)",
                 config.router_config.queue_size, config.router_config.queue_timeout_secs
             );
         }
+        None => {
+            info!(
+                "Rate limiting enabled (max_concurrent_requests = {}, queue disabled)",
+                config.router_config.max_concurrent_requests
+            );
+        }
+    }
 
     let app_state = Arc::new(AppState {
         router,

sgl-router/src/service_discovery.rs

@@ -532,7 +532,7 @@ mod tests {
         Arc::new(AppContext {
             client: reqwest::Client::new(),
             router_config: router_config.clone(),
-            rate_limiter: Arc::new(TokenBucket::new(1000, 1000)),
+            rate_limiter: Some(Arc::new(TokenBucket::new(1000, 1000))),
             worker_registry: Arc::new(crate::core::WorkerRegistry::new()),
             policy_registry: Arc::new(crate::policies::PolicyRegistry::new(
                 router_config.policy.clone(),