Use process reaper for cleanup (#6253)

python/ray/scripts/scripts.py

@@ -327,7 +327,8 @@ def start(node_ip_address, redis_address, address, redis_port,
             include_java=False,
         )
 
-        node = ray.node.Node(ray_params, head=True, shutdown_at_exit=block)
+        node = ray.node.Node(
+            ray_params, head=True, shutdown_at_exit=block, spawn_reaper=block)
         redis_address = node.redis_address
 
         logger.info(
@@ -395,7 +396,8 @@ def start(node_ip_address, redis_address, address, redis_port,
         check_no_existing_redis_clients(ray_params.node_ip_address,
                                         redis_client)
         ray_params.update(redis_address=redis_address)
-        node = ray.node.Node(ray_params, head=False, shutdown_at_exit=block)
+        node = ray.node.Node(
+            ray_params, head=False, shutdown_at_exit=block, spawn_reaper=block)
         logger.info("\nStarted Ray on this node. If you wish to terminate the "
                     "processes that have been started, run\n\n"
                     "    ray stop")
@@ -436,7 +438,6 @@ def stop(force, verbose):
         # See STANDARD FORMAT SPECIFIERS section of
         # http://man7.org/linux/man-pages/man1/ps.1.html
         # about comm and args. This can help avoid killing non-ray processes.
-
         # Format:
         # Keyword to filter, filter by command (True)/filter by args (False)
         ["raylet", True],
@@ -450,12 +451,9 @@ def stop(force, verbose):
         ["log_monitor.py", False],
         ["reporter.py", False],
         ["dashboard.py", False],
+        ["ray_process_reaper.py", False],
     ]
 
-    signal_name = "TERM"
-    if force:
-        signal_name = "KILL"
-
     for process in processes_to_kill:
         keyword, filter_by_cmd = process
         if filter_by_cmd:
@@ -475,7 +473,7 @@ def stop(force, verbose):
             "kill -s {} $(ps ax -o {} | grep {} | grep -v grep {} | grep ray |"
             "awk '{{ print $1 }}') 2> /dev/null".format(
                 # ^^ This is how you escape braces in python format string.
-                signal_name,
+                "KILL" if force else "TERM",
                 ps_format,
                 keyword,
                 debug_operator))