fix: dynamo-run pass proper args using register-llm (#1230)

launch/dynamo-run/src/subprocess/vllm_inc.py

@@ -157,7 +157,7 @@ async def init(runtime: DistributedRuntime, config: Config):
         # KV routing relies on logging KV metrics
         "disable_log_stats": False,
     }
-    if config.kv_block_size:
+    assert config.kv_block_size > 0, "Must use non-negative integer for KV Block Size"
     arg_map["block_size"] = config.kv_block_size
 
     if config.context_length:
@@ -201,7 +201,14 @@ async def init(runtime: DistributedRuntime, config: Config):
     engine_client = await engine_context.__aenter__()
 
     await register_llm(
-        ModelType.Backend, endpoint, config.model_path, config.model_name
+        ModelType.Backend,
+        endpoint,
+        config.model_path,
+        config.model_name,
+        context_length=arg_map.get(
+            "max_model_len", None
+        ),  # if None, takes length from tokenizer
+        kv_cache_block_size=arg_map["block_size"],
     )
     handler = RequestHandler(component, engine_client, default_sampling_params)
     handler.setup_kv_metrics()

lib/bindings/python/src/dynamo/_core.pyi

@@ -603,7 +603,7 @@ class ModelType:
     """What type of request this model needs: Chat, Component or Backend (pre-processed)"""
     ...
 
-async def register_llm(model_type: ModelType, endpoint: Endpoint, model_path: str, model_name: Optional[str]) -> None:
+async def register_llm(model_type: ModelType, endpoint: Endpoint, model_path: str, model_name: Optional[str] = None, context_length: Optional[int] = None, kv_cache_block_size: Optional[int] = None) -> None:
     """Attach the model at path to the given endpoint, and advertise it as model_type"""
     ...