[router] add --log-level to sgl-router (#6512)

sgl-router/README.md

@@ -79,7 +79,7 @@ router = Router(
 )
 ```
 
-Use the `--verbose` flag with the CLI for more detailed logs.
+Use the `--log-level` flag with the CLI to set [log level](https://docs.sglang.ai/backend/server_arguments.html#logging).
 
 ### Metrics
 

sgl-router/py_src/sglang_router/launch_router.py

@@ -48,8 +48,8 @@ class RouterArgs:
     eviction_interval: int = 60
     max_tree_size: int = 2**24
     max_payload_size: int = 256 * 1024 * 1024  # 256MB default for large batches
-    verbose: bool = False
     log_dir: Optional[str] = None
+    log_level: Optional[str] = None
     # Service discovery configuration
     service_discovery: bool = False
     selector: Dict[str, str] = dataclasses.field(default_factory=dict)
@@ -178,17 +178,19 @@ class RouterArgs:
             default=RouterArgs.max_payload_size,
             help="Maximum payload size in bytes",
         )
-        parser.add_argument(
-            f"--{prefix}verbose",
-            action="store_true",
-            help="Enable verbose logging",
-        )
         parser.add_argument(
             f"--{prefix}log-dir",
             type=str,
             default=None,
             help="Directory to store log files. If not specified, logs are only output to console.",
         )
+        parser.add_argument(
+            f"--{prefix}log-level",
+            type=str,
+            default="info",
+            choices=["debug", "info", "warning", "error", "critical"],
+            help="Set the logging level. If not specified, defaults to INFO.",
+        )
         parser.add_argument(
             f"--{prefix}service-discovery",
             action="store_true",
@@ -275,8 +277,8 @@ class RouterArgs:
             eviction_interval=getattr(args, f"{prefix}eviction_interval"),
             max_tree_size=getattr(args, f"{prefix}max_tree_size"),
             max_payload_size=getattr(args, f"{prefix}max_payload_size"),
-            verbose=getattr(args, f"{prefix}verbose", False),
             log_dir=getattr(args, f"{prefix}log_dir", None),
+            log_level=getattr(args, f"{prefix}log_level", None),
             service_discovery=getattr(args, f"{prefix}service_discovery", False),
             selector=cls._parse_selector(getattr(args, f"{prefix}selector", None)),
             service_discovery_port=getattr(args, f"{prefix}service_discovery_port"),
@@ -404,8 +406,8 @@ def launch_router(args: argparse.Namespace) -> Optional[Router]:
             eviction_interval_secs=router_args.eviction_interval,
             max_tree_size=router_args.max_tree_size,
             max_payload_size=router_args.max_payload_size,
-            verbose=router_args.verbose,
             log_dir=router_args.log_dir,
+            log_level=router_args.log_level,
             service_discovery=router_args.service_discovery,
             selector=router_args.selector,
             service_discovery_port=router_args.service_discovery_port,

sgl-router/py_src/sglang_router/router.py

@@ -31,8 +31,8 @@ class Router:
             routing. Default: 60
         max_payload_size: Maximum payload size in bytes. Default: 256MB
         max_tree_size: Maximum size of the approximation tree for cache-aware routing. Default: 2^24
-        verbose: Enable verbose logging. Default: False
         log_dir: Directory to store log files. If None, logs are only output to console. Default: None
+        log_level: Logging level. Options: 'debug', 'info', 'warning', 'error', 'critical'.
         service_discovery: Enable Kubernetes service discovery. When enabled, the router will
             automatically discover worker pods based on the selector. Default: False
         selector: Dictionary mapping of label keys to values for Kubernetes pod selection.
@@ -66,8 +66,8 @@ class Router:
         eviction_interval_secs: int = 60,
         max_tree_size: int = 2**24,
         max_payload_size: int = 256 * 1024 * 1024,  # 256MB
-        verbose: bool = False,
         log_dir: Optional[str] = None,
+        log_level: Optional[str] = None,
         service_discovery: bool = False,
         selector: Dict[str, str] = None,
         service_discovery_port: int = 80,
@@ -100,8 +100,8 @@ class Router:
             eviction_interval_secs=eviction_interval_secs,
             max_tree_size=max_tree_size,
             max_payload_size=max_payload_size,
-            verbose=verbose,
             log_dir=log_dir,
+            log_level=log_level,
             service_discovery=service_discovery,
             selector=selector,
             service_discovery_port=service_discovery_port,

sgl-router/py_test/test_launch_router.py

@@ -38,6 +38,7 @@ class TestLaunchRouter(unittest.TestCase):
             max_payload_size=256 * 1024 * 1024,  # 256MB
             verbose=False,
             log_dir=None,
+            log_level=None,
             service_discovery=False,
             selector=None,
             service_discovery_port=80,

sgl-router/src/config/types.rs

@@ -27,8 +27,8 @@ pub struct RouterConfig {
     pub metrics: Option<MetricsConfig>,
     /// Log directory (None = stdout only)
     pub log_dir: Option<String>,
-    /// Verbose logging
-    pub verbose: bool,
+    /// Log level (None = info)
+    pub log_level: Option<String>,
 }
 
 /// Routing mode configuration
@@ -177,7 +177,7 @@ impl Default for RouterConfig {
             discovery: None,
             metrics: None,
             log_dir: None,
-            verbose: false,
+            log_level: None,
         }
     }
 }

sgl-router/src/lib.rs

@@ -37,8 +37,8 @@ struct Router {
     eviction_interval_secs: u64,
     max_tree_size: usize,
     max_payload_size: usize,
-    verbose: bool,
     log_dir: Option<String>,
+    log_level: Option<String>,
     service_discovery: bool,
     selector: HashMap<String, String>,
     service_discovery_port: u16,
@@ -129,7 +129,7 @@ impl Router {
             discovery,
             metrics,
             log_dir: self.log_dir.clone(),
-            verbose: self.verbose,
+            log_level: self.log_level.clone(),
         })
     }
 }
@@ -150,8 +150,8 @@ impl Router {
         eviction_interval_secs = 60,
         max_tree_size = 2usize.pow(24),
         max_payload_size = 256 * 1024 * 1024,  // 256MB default for large batches
-        verbose = false,
         log_dir = None,
+        log_level = None,
         service_discovery = false,
         selector = HashMap::new(),
         service_discovery_port = 80,
@@ -179,8 +179,8 @@ impl Router {
         eviction_interval_secs: u64,
         max_tree_size: usize,
         max_payload_size: usize,
-        verbose: bool,
         log_dir: Option<String>,
+        log_level: Option<String>,
         service_discovery: bool,
         selector: HashMap<String, String>,
         service_discovery_port: u16,
@@ -208,8 +208,8 @@ impl Router {
             eviction_interval_secs,
             max_tree_size,
             max_payload_size,
-            verbose,
             log_dir,
+            log_level,
             service_discovery,
             selector,
             service_discovery_port,
@@ -283,9 +283,9 @@ impl Router {
                 port: self.port,
                 worker_urls: self.worker_urls.clone(),
                 policy_config,
-                verbose: self.verbose,
                 max_payload_size: self.max_payload_size,
                 log_dir: self.log_dir.clone(),
+                log_level: self.log_level.clone(),
                 service_discovery_config,
                 prometheus_config,
                 request_timeout_secs: self.request_timeout_secs,

sgl-router/src/server.rs

@@ -278,9 +278,9 @@ pub struct ServerConfig {
     pub port: u16,
     pub worker_urls: Vec<String>,
     pub policy_config: PolicyConfig,
-    pub verbose: bool,
     pub max_payload_size: usize,
     pub log_dir: Option<String>,
+    pub log_level: Option<String>,
     pub service_discovery_config: Option<ServiceDiscoveryConfig>,
     pub prometheus_config: Option<PrometheusConfig>,
     pub request_timeout_secs: u64,
@@ -292,11 +292,17 @@ pub async fn startup(config: ServerConfig) -> std::io::Result<()> {
 
     let _log_guard = if !LOGGING_INITIALIZED.swap(true, Ordering::SeqCst) {
         Some(logging::init_logging(LoggingConfig {
-            level: if config.verbose {
-                Level::DEBUG
-            } else {
-                Level::INFO
-            },
+            level: config
+                .log_level
+                .as_deref()
+                .and_then(|s| match s.to_uppercase().parse::<Level>() {
+                    Ok(l) => Some(l),
+                    Err(_) => {
+                        warn!("Invalid log level string: '{}'. Defaulting to INFO.", s);
+                        None
+                    }
+                })
+                .unwrap_or(Level::INFO),
             json_format: false,
             log_dir: config.log_dir.clone(),
             colorize: true,