From da3a4aabb42d809b1bcea344b5d754a68ffd47cd Mon Sep 17 00:00:00 2001
From: Jan David Mol <mol@astron.nl>
Date: Fri, 4 Dec 2020 09:54:57 +0100
Subject: [PATCH] Only reconnect once if connection fails -- we only want to
catch exotic errors, not cover up hardware/infra failure
---
RCUSCC/RCUSCC/RCUSCC.py | 58 +++++++++++++++++++++++++++--------------
1 file changed, 39 insertions(+), 19 deletions(-)
diff --git a/RCUSCC/RCUSCC/RCUSCC.py b/RCUSCC/RCUSCC/RCUSCC.py
index 73cf614ca..7655e4e7a 100644
--- a/RCUSCC/RCUSCC/RCUSCC.py
+++ b/RCUSCC/RCUSCC/RCUSCC.py
@@ -74,38 +74,34 @@ class OPCUAConnection(Thread):
Run a connector function in the background, until it succeeds.
"""
- def __init__(self, client, init_func, fault_func, streams, try_interval=2):
+ def __init__(self, client, on_func, fault_func, streams, try_interval=2):
super().__init__(daemon=True)
self.client = client
- self.init_func = init_func
+ self.on_func = on_func
self.fault_func = fault_func
self.try_interval = try_interval
self.streams = streams
self.stopping = False
-
- self.start()
+ self.connected = False
def _servername(self):
return self.client.server_url.geturl()
- def try_connect(self):
+ def connect(self):
try:
self.streams.debug_stream("Connecting to server %s", self._servername())
self.client.connect()
+ self.connected = True
self.streams.debug_stream("Connected to server. Initialising.")
-
- self.init_func()
-
return True
except socket.error as e:
self.streams.error_stream("Could not connect to server %s: %s", self._servername(), e)
-
- # signal that we're disconnected
- self.fault_func()
return False
- def try_disconnect(self):
+ def disconnect(self):
+ self.connected = False # always force a reconnect, regardless of a successful disconnect
+
try:
self.client.disconnect()
except Exception as e:
@@ -114,8 +110,14 @@ class OPCUAConnection(Thread):
def run(self):
while not self.stopping:
# keep trying to connect
- while not self.stopping and not self.try_connect():
- time.sleep(self.try_interval)
+ if not self.connected:
+ if self.connect():
+ self.on_func()
+ else:
+ # we retry only once, to catch exotic network issues. if the infra or hardware is down,
+ # our device cannot help, and must be reinitialised after the infra or hardware is fixed.
+ self.fault_func()
+ return
# keep checking if the connection is still alive
try:
@@ -126,7 +128,7 @@ class OPCUAConnection(Thread):
self.streams.error_stream("Lost connection to server %s: %s", self._servername(), e)
# technically, we may not have dropped the connection, but encounter a different error. so explicitly disconnect.
- self.try_disconnect()
+ self.disconnect()
# signal that we're disconnected
self.fault_func()
@@ -139,7 +141,7 @@ class OPCUAConnection(Thread):
self.stopping = True
self.join()
- self.try_disconnect()
+ self.disconnect()
class RCUSCC(Device):
"""
@@ -262,7 +264,7 @@ class RCUSCC(Device):
return DummyNode()
- def _init_opcua(self):
+ def _map_attributes(self):
try:
self.name_space_index = self.client.get_namespace_index("http://lofar.eu")
except Exception as e:
@@ -367,7 +369,21 @@ class RCUSCC(Device):
self.client = opcua.Client("opc.tcp://{}:{}/".format(self.OPC_Server_Name, self.OPC_Server_Port), self.OPC_Time_Out) # timeout in seconds
# Connect to OPC-UA -- will set ON state on success
- self.opcua_connection = OPCUAConnection(self.client, self._init_opcua, self.Fault, self)
+ self.opcua_connection = OPCUAConnection(self.client, self.On, self.Fault, self)
+
+ if not self.opcua_connection.connect():
+ # hardware or infra is down -- needs fixing first
+ self.Fault()
+ return
+
+ # Retrieve and map server attributes
+ self._map_attributes()
+
+ # Start keep-alive
+ self.opcua_connection.start()
+
+ # Everything went ok -- go online
+ self.On()
# PROTECTED REGION END # // RCUSCC.init_device
@@ -568,11 +584,15 @@ class RCUSCC(Device):
:return:None
"""
+ # Turn off
self.set_state(DevState.OFF)
- # stop reconnecting before disconnect
+ # Stop keep-alive
self.opcua_connection.stop()
+ # Turn off again, in case of race conditions through reconnecting
+ self.set_state(DevState.OFF)
+
# PROTECTED REGION END # // RCUSCC.Off
@command(
--
GitLab