[V1] [4/N] API Server: ZMQ/MP Utilities (#11541)

vllm/entrypoints/openai/api_server.py

@@ -68,7 +68,7 @@ from vllm.entrypoints.utils import with_cancellation
 from vllm.logger import init_logger
 from vllm.usage.usage_lib import UsageContext
 from vllm.utils import (FlexibleArgumentParser, get_open_zmq_ipc_path,
-                        is_valid_ipv6_address, set_ulimit)
+                        is_valid_ipv6_address, kill_process_tree, set_ulimit)
 from vllm.version import __version__ as VLLM_VERSION
 
 TIMEOUT_KEEP_ALIVE = 5  # seconds
@@ -737,6 +737,15 @@ async def run_server(args, **uvicorn_kwargs) -> None:
 
     signal.signal(signal.SIGTERM, signal_handler)
 
+    # The child processes will send SIGQUIT to this process when
+    # any error happens. This process then clean up the whole tree.
+    # TODO(rob): move this into AsyncLLM.__init__ once we remove
+    # the context manager below.
+    def sigquit_handler(signum, frame):
+        kill_process_tree(os.getpid())
+
+    signal.signal(signal.SIGQUIT, sigquit_handler)
+
     async with build_async_engine_client(args) as engine_client:
         app = build_app(args)