¡He tenido un error intermitente durante meses y estoy atascado! Se agradece la ayuda.

 class ContentFile(models.Model): """ Represents the metadata for a single document. """ name = models.CharField(max_length=200) set = models.ForeignKey(Set, related_name='contentfile_set', on_delete=models.CASCADE) location = models.FileField(upload_to=get_content_file_upload_path) class Meta: app_label = 'ProtocolManager' unique_together = ('set', 'location') def __str__(self): return f"File {self.name} at location {str(self.location)} attached to {self.set}" @receiver(models.signals.post_delete, sender=ContentFile) def delete_file(sender, instance, *args, **kwargs): """ Delete orphaned file once last ContentFile is removed. """ log.info(f"Checking {instance.location} for existing ContentFile") if instance.location: from django.db import connection from django.db import reset_queries reset_queries() files_queryset = ContentFile.objects.filter(location=instance.location) if not files_queryset.exists(): log.info(f"ContentFile does not exist for {instance.location}, deleting...") log.info(f"SQL: {connection.queries}") log.info(f"files_queryset: {list(files_queryset.all())}") log.info(f"count: {files_queryset.count()}") log.info(f"exists: {files_queryset.exists()}") instance.location.delete(save=False)

La lógica es bastante simple. Cuando se elimina una fila de ContentFile, si fue la última que hace referencia a una ubicación de archivo real, eliminamos el archivo en sí (en AWS S3, si es importante). El 99 % de las veces esto funciona como se esperaba, pero a veces falla y, cuando falla, parece fallar para todos los ContentFiles asociados con un conjunto determinado. Agregué el registro detallado para tratar de obtener más pistas, pero hoy finalmente se reprodujo por primera vez en meses y el registro es simplemente frustrante:

 ... 2021-06-08 20:30:05,329 [INFO] ProtocolManager.models: Checking 1129/314.pdf for existing ContentFile 2021-06-08 20:30:05,335 [INFO] ProtocolManager.models: ContentFile does not exist for 1129/314.pdf, deleting... 2021-06-08 20:30:05,335 [INFO] ProtocolManager.models: SQL: [{'sql': "SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/314.pdf' LIMIT 1", 'time': '0.005'}] 2021-06-08 20:30:05,604 [INFO] ProtocolManager.models: files_queryset: [<ContentFile: File hypovolemic-traumatic-shockpdf.pdf at location 1129/314.pdf attached to Set v2021.6.8 '586-Joachim-Plattin Ambulance PCG' (1130-EDIT)>] 2021-06-08 20:30:05,610 [INFO] ProtocolManager.models: count: 0 2021-06-08 20:30:05,618 [INFO] ProtocolManager.models: exists: False 2021-06-08 20:30:05,685 [INFO] ProtocolManager.models: Checking 1116/312.pdf for existing ContentFile 2021-06-08 20:30:05,690 [INFO] ProtocolManager.models: Checking 1109/310.pdf for existing ContentFile 2021-06-08 20:30:05,700 [INFO] ProtocolManager.models: Checking 1101/306.pdf for existing ContentFile 2021-06-08 20:30:05,705 [INFO] ProtocolManager.models: Checking 1095/304.pdf for existing ContentFile 2021-06-08 20:30:05,711 [INFO] ProtocolManager.models: Checking 1089/301.pdf for existing ContentFile 2021-06-08 20:30:05,721 [INFO] ProtocolManager.models: Checking 1083/296.pdf for existing ContentFile 2021-06-08 20:30:05,726 [INFO] ProtocolManager.models: Checking 1080/292.pdf for existing ContentFile 2021-06-08 20:30:05,734 [INFO] ProtocolManager.models: Checking 1077/290.pdf for existing ContentFile 2021-06-08 20:30:05,739 [INFO] ProtocolManager.models: Checking 1075/289.pdf for existing ContentFile 2021-06-08 20:30:05,747 [INFO] ProtocolManager.models: Checking 1072/287.pdf for existing ContentFile 2021-06-08 20:30:05,754 [INFO] ProtocolManager.models: Checking 1066/285.pdf for existing ContentFile 2021-06-08 20:30:05,763 [INFO] ProtocolManager.models: Checking 1129/307.pdf for existing ContentFile 2021-06-08 20:30:05,768 [INFO] ProtocolManager.models: ContentFile does not exist for 1129/307.pdf, deleting... 2021-06-08 20:30:05,768 [INFO] ProtocolManager.models: SQL: [{'sql': "SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/307.pdf' LIMIT 1", 'time': '0.004'}] 2021-06-08 20:30:05,943 [INFO] ProtocolManager.models: files_queryset: [<ContentFile: File 0004-ift-medications.pdf at location 1129/307.pdf attached to Set v2021.6.8 '586-Joachim-Plattin Ambulance PCG' (1130-EDIT)>] 2021-06-08 20:30:05,947 [INFO] ProtocolManager.models: count: 0 2021-06-08 20:30:05,952 [INFO] ProtocolManager.models: exists: False 2021-06-08 20:30:05,982 [INFO] ProtocolManager.models: Checking 855/123.pdf for existing ContentFile 2021-06-08 20:30:05,987 [INFO] ProtocolManager.models: Checking 1096/122.pdf for existing ContentFile 2021-06-08 20:30:05,992 [INFO] ProtocolManager.models: Checking 855/121.pdf for existing ContentFile 2021-06-08 20:30:05,997 [INFO] ProtocolManager.models: Checking 1116/295.pdf for existing ContentFile ...

En el registro, muestra que, de hecho, existe la fila esperada de ContentFile en la ubicación en cuestión (la salida de list(files_queryset.all()) ) pero tanto count() es 0 como exist() es falso.

¿Alguien tiene alguna idea de por qué esto podría estar sucediendo? ¿Problemas intermitentes de la base de datos para AWS RDS, tal vez?

La base de datos inicia sesión en el mismo período (tenga en cuenta que eliminé algunos campos extraños del modelo anterior para mayor claridad, todavía los ve en las consultas de la base de datos):

 2021-06-08 20:30:05,335 [DEBUG] django.db.backends: (0.005) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/314.pdf' LIMIT 1; args=('1129/314.pdf',) 2021-06-08 20:30:05,593 [DEBUG] django.db.backends: (0.257) SELECT `ProtocolManager_contentfile`.`id`, `ProtocolManager_contentfile`.`name`, `ProtocolManager_contentfile`.`set_id`, `ProtocolManager_contentfile`.`location`, `ProtocolManager_contentfile`.`extractedText`, `ProtocolManager_contentfile`.`pages`, `ProtocolManager_contentfile`.`md5`, `ProtocolManager_contentfile`.`fileSize`, `ProtocolManager_contentfile`.`createdOn`, `ProtocolManager_contentfile`.`createdBy_id`, `ProtocolManager_contentfile`.`lastUpdated`, `ProtocolManager_contentfile`.`updatedBy_id` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/314.pdf'; args=('1129/314.pdf',) 2021-06-08 20:30:05,602 [DEBUG] django.db.backends: (0.007) SELECT `ProtocolManager_set`.`id`, `ProtocolManager_set`.`setMeta_id`, `ProtocolManager_set`.`originSet_id`, `ProtocolManager_set`.`majorVersion`, `ProtocolManager_set`.`minorVersion`, `ProtocolManager_set`.`revisionVersion`, `ProtocolManager_set`.`acknowledgmentSetID`, `ProtocolManager_set`.`receiptAckText`, `ProtocolManager_set`.`pubLevel`, `ProtocolManager_set`.`minOSiOS`, `ProtocolManager_set`.`minOSAndroid`, `ProtocolManager_set`.`minVersioniOS`, `ProtocolManager_set`.`minVersionAndroid`, `ProtocolManager_set`.`createdOn`, `ProtocolManager_set`.`createdBy_id`, `ProtocolManager_set`.`lastUpdated`, `ProtocolManager_set`.`updatedBy_id` FROM `ProtocolManager_set` WHERE `ProtocolManager_set`.`id` = 1130 LIMIT 21; args=(1130,) 2021-06-08 20:30:05,604 [DEBUG] django.db.backends: (0.001) SELECT `ProtocolManager_setmeta`.`id`, `ProtocolManager_setmeta`.`region_id`, `ProtocolManager_setmeta`.`setName`, `ProtocolManager_setmeta`.`displayName`, `ProtocolManager_setmeta`.`isOffline`, `ProtocolManager_setmeta`.`offlineReason`, `ProtocolManager_setmeta`.`discontinued`, `ProtocolManager_setmeta`.`invisible`, `ProtocolManager_setmeta`.`isSponsored`, `ProtocolManager_setmeta`.`isOutdated`, `ProtocolManager_setmeta`.`lastUID`, `ProtocolManager_setmeta`.`companyNumberLabel`, `ProtocolManager_setmeta`.`companyNumberRegex`, `ProtocolManager_setmeta`.`customBundleId`, `ProtocolManager_setmeta`.`betaEnabled`, `ProtocolManager_setmeta`.`restrictedMD5`, `ProtocolManager_setmeta`.`createdOn`, `ProtocolManager_setmeta`.`lastUpdated`, `ProtocolManager_setmeta`.`createdBy_id`, `ProtocolManager_setmeta`.`updatedBy_id` FROM `ProtocolManager_setmeta` WHERE `ProtocolManager_setmeta`.`id` = 586 LIMIT 21; args=(586,) 2021-06-08 20:30:05,610 [DEBUG] django.db.backends: (0.005) SELECT COUNT(*) AS `__count` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/314.pdf'; args=('1129/314.pdf',) 2021-06-08 20:30:05,617 [DEBUG] django.db.backends: (0.007) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/314.pdf' LIMIT 1; args=('1129/314.pdf',) 2021-06-08 20:30:05,690 [DEBUG] django.db.backends: (0.004) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1116/312.pdf' LIMIT 1; args=('1116/312.pdf',) 2021-06-08 20:30:05,700 [DEBUG] django.db.backends: (0.009) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1109/310.pdf' LIMIT 1; args=('1109/310.pdf',) 2021-06-08 20:30:05,705 [DEBUG] django.db.backends: (0.004) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1101/306.pdf' LIMIT 1; args=('1101/306.pdf',) 2021-06-08 20:30:05,711 [DEBUG] django.db.backends: (0.006) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1095/304.pdf' LIMIT 1; args=('1095/304.pdf',) 2021-06-08 20:30:05,721 [DEBUG] django.db.backends: (0.009) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1089/301.pdf' LIMIT 1; args=('1089/301.pdf',) 2021-06-08 20:30:05,725 [DEBUG] django.db.backends: (0.004) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1083/296.pdf' LIMIT 1; args=('1083/296.pdf',) 2021-06-08 20:30:05,734 [DEBUG] django.db.backends: (0.008) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1080/292.pdf' LIMIT 1; args=('1080/292.pdf',) 2021-06-08 20:30:05,739 [DEBUG] django.db.backends: (0.004) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1077/290.pdf' LIMIT 1; args=('1077/290.pdf',) 2021-06-08 20:30:05,746 [DEBUG] django.db.backends: (0.007) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1075/289.pdf' LIMIT 1; args=('1075/289.pdf',) 2021-06-08 20:30:05,754 [DEBUG] django.db.backends: (0.007) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1072/287.pdf' LIMIT 1; args=('1072/287.pdf',) 2021-06-08 20:30:05,762 [DEBUG] django.db.backends: (0.007) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1066/285.pdf' LIMIT 1; args=('1066/285.pdf',) 2021-06-08 20:30:05,767 [DEBUG] django.db.backends: (0.004) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/307.pdf' LIMIT 1; args=('1129/307.pdf',) 2021-06-08 20:30:05,937 [DEBUG] django.db.backends: (0.169) SELECT `ProtocolManager_contentfile`.`id`, `ProtocolManager_contentfile`.`name`, `ProtocolManager_contentfile`.`set_id`, `ProtocolManager_contentfile`.`location`, `ProtocolManager_contentfile`.`extractedText`, `ProtocolManager_contentfile`.`pages`, `ProtocolManager_contentfile`.`md5`, `ProtocolManager_contentfile`.`fileSize`, `ProtocolManager_contentfile`.`createdOn`, `ProtocolManager_contentfile`.`createdBy_id`, `ProtocolManager_contentfile`.`lastUpdated`, `ProtocolManager_contentfile`.`updatedBy_id` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/307.pdf'; args=('1129/307.pdf',) 2021-06-08 20:30:05,940 [DEBUG] django.db.backends: (0.001) SELECT `ProtocolManager_set`.`id`, `ProtocolManager_set`.`setMeta_id`, `ProtocolManager_set`.`originSet_id`, `ProtocolManager_set`.`majorVersion`, `ProtocolManager_set`.`minorVersion`, `ProtocolManager_set`.`revisionVersion`, `ProtocolManager_set`.`acknowledgmentSetID`, `ProtocolManager_set`.`receiptAckText`, `ProtocolManager_set`.`pubLevel`, `ProtocolManager_set`.`minOSiOS`, `ProtocolManager_set`.`minOSAndroid`, `ProtocolManager_set`.`minVersioniOS`, `ProtocolManager_set`.`minVersionAndroid`, `ProtocolManager_set`.`createdOn`, `ProtocolManager_set`.`createdBy_id`, `ProtocolManager_set`.`lastUpdated`, `ProtocolManager_set`.`updatedBy_id` FROM `ProtocolManager_set` WHERE `ProtocolManager_set`.`id` = 1130 LIMIT 21; args=(1130,) 2021-06-08 20:30:05,942 [DEBUG] django.db.backends: (0.001) SELECT `ProtocolManager_setmeta`.`id`, `ProtocolManager_setmeta`.`region_id`, `ProtocolManager_setmeta`.`setName`, `ProtocolManager_setmeta`.`displayName`, `ProtocolManager_setmeta`.`isOffline`, `ProtocolManager_setmeta`.`offlineReason`, `ProtocolManager_setmeta`.`discontinued`, `ProtocolManager_setmeta`.`invisible`, `ProtocolManager_setmeta`.`isSponsored`, `ProtocolManager_setmeta`.`isOutdated`, `ProtocolManager_setmeta`.`lastUID`, `ProtocolManager_setmeta`.`companyNumberLabel`, `ProtocolManager_setmeta`.`companyNumberRegex`, `ProtocolManager_setmeta`.`customBundleId`, `ProtocolManager_setmeta`.`betaEnabled`, `ProtocolManager_setmeta`.`restrictedMD5`, `ProtocolManager_setmeta`.`createdOn`, `ProtocolManager_setmeta`.`lastUpdated`, `ProtocolManager_setmeta`.`createdBy_id`, `ProtocolManager_setmeta`.`updatedBy_id` FROM `ProtocolManager_setmeta` WHERE `ProtocolManager_setmeta`.`id` = 586 LIMIT 21; args=(586,) 2021-06-08 20:30:05,947 [DEBUG] django.db.backends: (0.004) SELECT COUNT(*) AS `__count` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/307.pdf'; args=('1129/307.pdf',) 2021-06-08 20:30:05,952 [DEBUG] django.db.backends: (0.004) SELECT (1) AS `a` FROM `ProtocolManager_contentfile` WHERE `ProtocolManager_contentfile`.`location` = '1129/307.pdf' LIMIT 1; args=('1129/307.pdf',)