[router] Expose worker startup secs & Return error instead of panic for router init (#3016)

sgl-router/py_src/sglang_router/launch_router.py

@@ -33,6 +33,7 @@ class RouterArgs:
 
     # Routing policy
     policy: str = "cache_aware"
+    worker_startup_timeout_secs: int = 300
     cache_threshold: float = 0.5
     balance_abs_threshold: int = 32
     balance_rel_threshold: float = 1.0001
@@ -87,6 +88,12 @@ class RouterArgs:
             choices=["random", "round_robin", "cache_aware"],
             help="Load balancing policy to use",
         )
+        parser.add_argument(
+            f"--{prefix}worker-startup-timeout-secs",
+            type=int,
+            default=RouterArgs.worker_startup_timeout_secs,
+            help="Timeout in seconds for worker startup",
+        )
         parser.add_argument(
             f"--{prefix}cache-threshold",
             type=float,
@@ -147,6 +154,9 @@ class RouterArgs:
             host=args.host,
             port=args.port,
             policy=getattr(args, f"{prefix}policy"),
+            worker_startup_timeout_secs=getattr(
+                args, f"{prefix}worker_startup_timeout_secs"
+            ),
             cache_threshold=getattr(args, f"{prefix}cache_threshold"),
             balance_abs_threshold=getattr(args, f"{prefix}balance_abs_threshold"),
             balance_rel_threshold=getattr(args, f"{prefix}balance_rel_threshold"),
@@ -188,9 +198,10 @@ def launch_router(args: argparse.Namespace) -> Optional[Router]:
 
         router = Router(
             worker_urls=router_args.worker_urls,
-            policy=policy_from_str(router_args.policy),
             host=router_args.host,
             port=router_args.port,
+            policy=policy_from_str(router_args.policy),
+            worker_startup_timeout_secs=router_args.worker_startup_timeout_secs,
             cache_threshold=router_args.cache_threshold,
             balance_abs_threshold=router_args.balance_abs_threshold,
             balance_rel_threshold=router_args.balance_rel_threshold,
@@ -205,7 +216,7 @@ def launch_router(args: argparse.Namespace) -> Optional[Router]:
 
     except Exception as e:
         logger.error(f"Error starting router: {e}")
-        return None
+        raise e
 
 
 class CustomHelpFormatter(
@@ -239,10 +250,7 @@ Examples:
 
 def main() -> None:
     router_args = parse_router_args(sys.argv[1:])
-    router = launch_router(router_args)
-
-    if router is None:
-        sys.exit(1)
+    launch_router(router_args)
 
 
 if __name__ == "__main__":