Only emit event if Update actually happens

router/table.go

@@ -105,8 +105,10 @@ func (t *table) Update(r Route) error {
 		return nil
 	}
 
+	if _, ok := t.routes[service][sum]; !ok {
 		t.routes[service][sum] = r
 		go t.sendEvent(&Event{Type: Update, Timestamp: time.Now(), Route: r})
+	}
 
 	return nil
 }