Don't copy monitoring address/port parameters into the DFK.

Prior to this PR, monitoring hub address and ZMQ port were stored as
attributes of the DFK. The address also existed as an attribute on
dfk.monitoring, and the ZMQ port was returned by dfk.monitoring.start

Afte this PR, those values are not added to the DFK, but instead are
accessed via dfk.monitoring.

These two attributes are now only set on a new executor when monitoring
is enabled, rather than always being intialised by the DFK. Default values
now come from the executor __init__ method, which is a more usual style
in Python for providing default values. See PR #3361

This is part of ongoing work to introduce more pluggable monitoring
network connectivity - see PR #3315

parsl/dataflow/dflow.py

@@ -113,14 +113,10 @@ def __init__(self, config: Config) -> None:
         self.monitoring: Optional[MonitoringHub]
         self.monitoring = config.monitoring
 
-        # hub address and port for interchange to connect
-        self.hub_address = None  # type: Optional[str]
-        self.hub_zmq_port = None  # type: Optional[int]
         if self.monitoring:
             if self.monitoring.logdir is None:
                 self.monitoring.logdir = self.run_dir
-            self.hub_address = self.monitoring.hub_address
-            self.hub_zmq_port = self.monitoring.start(self.run_id, self.run_dir, self.config.run_dir)
+            self.monitoring.start(self.run_id, self.run_dir, self.config.run_dir)
 
         self.time_began = datetime.datetime.now()
         self.time_completed: Optional[datetime.datetime] = None
@@ -1181,9 +1177,9 @@ def add_executors(self, executors: Sequence[ParslExecutor]) -> None:
         for executor in executors:
             executor.run_id = self.run_id
             executor.run_dir = self.run_dir
-            executor.hub_address = self.hub_address
-            executor.hub_zmq_port = self.hub_zmq_port
             if self.monitoring:
+                executor.hub_address = self.monitoring.hub_address
+                executor.hub_zmq_port = self.monitoring.hub_zmq_port
                 executor.monitoring_radio = self.monitoring.radio
             if hasattr(executor, 'provider'):
                 if hasattr(executor.provider, 'script_dir'):

parsl/monitoring/monitoring.py

@@ -105,7 +105,7 @@ def __init__(self,
         self.resource_monitoring_enabled = resource_monitoring_enabled
         self.resource_monitoring_interval = resource_monitoring_interval
 
-    def start(self, run_id: str, dfk_run_dir: str, config_run_dir: Union[str, os.PathLike]) -> int:
+    def start(self, run_id: str, dfk_run_dir: str, config_run_dir: Union[str, os.PathLike]) -> None:
 
         logger.debug("Starting MonitoringHub")
 
@@ -207,7 +207,7 @@ def start(self, run_id: str, dfk_run_dir: str, config_run_dir: Union[str, os.Pat
 
         logger.info("Monitoring Hub initialized")
 
-        return zmq_port
+        self.hub_zmq_port = zmq_port
 
     # TODO: tighten the Any message format
     def send(self, mtype: MessageType, message: Any) -> None:

parsl/tests/test_monitoring/test_fuzz_zmq.py

@@ -44,8 +44,8 @@ def test_row_counts():
     #   the latter is what i'm most suspicious of in my present investigation
 
     # dig out the interchange port...
-    hub_address = parsl.dfk().hub_address
-    hub_zmq_port = parsl.dfk().hub_zmq_port
+    hub_address = parsl.dfk().monitoring.hub_address
+    hub_zmq_port = parsl.dfk().monitoring.hub_zmq_port
 
     # this will send a string to a new socket connection
     with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s: