Change default multiprocessing behavior to spawn

distributed/deploy/tests/test_ssh.py

@@ -38,14 +38,14 @@ async def test_keywords():
             "memory_limit": "2 GiB",
             "death_timeout": "5s",
         },
-        scheduler_options={"idle_timeout": "5s", "port": 0},
+        scheduler_options={"idle_timeout": "10s", "port": 0},
     ) as cluster:
         async with Client(cluster, asynchronous=True) as client:
             assert (
                 await client.run_on_scheduler(
                     lambda dask_scheduler: dask_scheduler.idle_timeout
                 )
-            ) == 5
+            ) == 10
             d = client.scheduler_info()["workers"]
             assert all(v["nthreads"] == 2 for v in d.values())
 

distributed/distributed.yaml

@@ -39,7 +39,7 @@ distributed:
 
   worker:
     blocked-handlers: []
-    multiprocessing-method: forkserver
+    multiprocessing-method: spawn
     use-file-locking: True
     connections:            # Maximum concurrent connections for data
       outgoing: 50          # This helps to control network saturation

distributed/nanny.py

@@ -597,6 +597,7 @@ async def kill(self, timeout=2, executor_wait=True):
                 "executor_wait": executor_wait,
             }
         )
+        await asyncio.sleep(0)  # otherwise we get broken pipe errors
         self.child_stop_q.close()
 
         while process.is_alive() and loop.time() < deadline: