From 7001b5e9bd5f46a2402c6bfa0f61f3d635769814 Mon Sep 17 00:00:00 2001
From: vitor-aignosi <vitor.santos@aignosi.com.br>
Date: Mon, 20 Oct 2025 15:27:05 -0300
Subject: [PATCH] SIENTIAPDE-1312  SIENTIAPDE-1318 Enhance OpcManager
 disconnection handling

- Introduced a disconnection_fallback method to attempt multiple disconnects from the OPC UA server, improving reliability.
- Updated error handling during connection attempts to ensure proper logging and notification of disconnection failures.
- Refactored disconnect method to utilize the new fallback mechanism and maintain metrics accurately.
---
 ingestor/managers/opc_manager.py | 68 +++++++++++++++++++++++---------
 1 file changed, 49 insertions(+), 19 deletions(-)

diff --git a/ingestor/managers/opc_manager.py b/ingestor/managers/opc_manager.py
index abd81c1..113473f 100644
--- a/ingestor/managers/opc_manager.py
+++ b/ingestor/managers/opc_manager.py
@@ -1,5 +1,7 @@
+import asyncio
 import json
 from pathlib import Path
+import traceback
 
 from asyncua import Client
 from asyncua.crypto.security_policies import SecurityPolicyBasic256
@@ -198,7 +200,7 @@ class OpcManager(BaseActivity):
             pod_uri = f'urn:sientia-do:pod:{self.pod_id}'
             self.client.application_uri = pod_uri
             self.client.product_uri = pod_uri
-            
+
             if self.cert_path:
                 await self.set_security()
             self.logger.info(f'Starting connection to {self.name}...')
@@ -208,11 +210,10 @@ class OpcManager(BaseActivity):
             ).set(1)
             self.logger.info(f'Connection to {self.name} successful.')
         except Exception as e:
-            if self.client:
-                try:
-                    await self.client.disconnect()
-                except Exception as internal_e:
-                    self.logger.error(f'And error occurred while creating connection from {self.name}, and an exception occurred while disconnecting: {internal_e}')
+            try:
+                await self.disconnect()
+            except Exception as internal_e:
+                self.logger.error(f'And error occurred while creating connection from {self.name}, and an exception occurred while disconnecting: {internal_e}')
 
             del self.client
             self.client = None
@@ -333,6 +334,28 @@ class OpcManager(BaseActivity):
         del self.subscriptions[subscription]
         self.logger.info(f'Unsubscribed from {subscription}.')
 
+    async def disconnection_fallback(self) -> list:
+        """
+        Tries 5 times to disconnect from the OPC UA server, with a delay of 100ms x try.
+        """
+
+        assert self.client is not None
+        error_stack = []
+        for i in range(5):
+            try:
+                self.logger.info(f'Disconnecting from OPC UA server, attempt {i+1} of 5')
+                await self.client.disconnect()
+                return []
+            except Exception as e:
+                self.logger.error(f'Failed to disconnect from OPC UA server: {e}')
+                error_stack.append({
+                    'attempt': i+1,
+                    'error': str(e),
+                    'traceback': traceback.format_exc(),
+                })
+                await asyncio.sleep(0.1 * i)
+        return error_stack
+
     async def disconnect(self):
         """
         Disconnects from the OPC UA server.
@@ -363,21 +386,28 @@ class OpcManager(BaseActivity):
         except Exception as sub_error:
             self.logger.error(f'Failed to clean up subscription: {sub_error}')
 
-        # Inserir backoff para disconnect, emitindo métrica e alerta
-        try:
-            await self.client.disconnect()
-        except Exception as conn_error:
-            self.logger.error(f'Failed to disconnect from OPC UA server: {conn_error}')
-            
-        finally:
-            del self.client
-            self.client = None
-            metrics.OPC_CONNECTION_STATUS.labels(
-                pod_id=self.pod_id, server_name=self.name, server_url=self.url
-            ).set(0)
-            metrics.OPC_TAGS_SUBSCRIBED.labels(pod_id=self.pod_id, server_name=self.name).set(0)
+        
+        errors = self.disconnection_fallback()
+
+        if errors:
+            self.send_notification(
+                metadata=self.metadata,
+                notification_id=f'OPC_DISCONNECTION_ERROR_{self.name}',
+                message=f'Failed to disconnect from OPC UA server {self.name} after 5 attempts',
+                block='opc_manager',
+                level=NotificationLevel.ERROR,
+                attachment_content=json.dumps(errors, indent=4),
+            )
+        else:
             self.logger.warning('Disconnected from OPC UA server.')
 
+        del self.client
+        self.client = None
+        metrics.OPC_CONNECTION_STATUS.labels(
+            pod_id=self.pod_id, server_name=self.name, server_url=self.url
+        ).set(0)
+        metrics.OPC_TAGS_SUBSCRIBED.labels(pod_id=self.pod_id, server_name=self.name).set(0)
+
     async def datachange_notification(self, node, _val, data):
         """
         Handles data change notifications for monitored OPC UA nodes.