Merge pull request #4848 from freenas/NAS-106197

NAS-106197 / 11.3 / Alert collisions are inevitable on TN HA; ignore them

gui/system/migrations/0047_remove_alert_unique_constraint.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.10.8 on 2020-05-27 10:38
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('system', '0046_legacy_ui'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='alert',
+            unique_together=set([]),
+        ),
+    ]

gui/system/models.py

@@ -492,11 +492,6 @@ class Alert(Model):
     dismissed = models.BooleanField()
     text = models.TextField()
 
-    class Meta:
-        unique_together = (
-            ('node', 'klass', 'key'),
-        )
-
 
 class AlertClasses(Model):
     classes = DictField(

src/middlewared/middlewared/plugins/alert.py

@@ -204,7 +204,8 @@ class AlertService(Service):
 
                 alert = Alert(**alert)
 
-                self.alerts.append(alert)
+                if not any(a.uuid == alert.uuid for a in self.alerts):
+                    self.alerts.append(alert)
 
         self.alert_source_last_run = defaultdict(lambda: datetime.min)
 
@@ -700,7 +701,7 @@ class AlertService(Service):
 
         return alerts
 
-    @periodic(3600)
+    @periodic(3600, run_on_start=False)
     @private
     async def flush_alerts(self):
         if (