Network monitoring system written in Python and Django, designed to be extensible, programmable, scalable and easy to use by end users: once the system is configured, monitoring checks, alerts and metric collection happens automatically.
I have observed a lot of errors like the following, coming from openwisp_monitoring.device.tasks.write_device_metrics:
Metric.DoesNotExist: Metric matching query does not exist.
File "openwisp_monitoring/monitoring/base/models.py", line 154, in _get_or_create
metric = cls.objects.get(**lookup_kwargs)
File "django/db/models/manager.py", line 85, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "django/db/models/query.py", line 435, in get
raise self.model.DoesNotExist(
UniqueViolation: duplicate key value violates unique constraint "monitoring_metric_key_field_name_content_t_bcaee2c5_uniq"
DETAIL: Key (key, field_name, content_type_id, object_id, main_tags)=(memory, percent_used, 24, 0cf10289-013c-4c87-adf9-92ce2e8ef354, {}) already exists.
File "django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
IntegrityError: duplicate key value violates unique constraint "monitoring_metric_key_field_name_content_t_bcaee2c5_uniq"
DETAIL: Key (key, field_name, content_type_id, object_id, main_tags)=(memory, percent_used, 24, 0cf10289-013c-4c87-adf9-92ce2e8ef354, {}) already exists.
File "celery/app/trace.py", line 734, in __protected_call__
return self.run(*args, **kwargs)
File "openwisp_monitoring/device/tasks.py", line 112, in write_device_metrics
device_data.writer.write(data, time, current)
File "openwisp_monitoring/device/writer.py", line 152, in write
self._write_memory(
File "openwisp_monitoring/device/writer.py", line 330, in _write_memory
metric, created = Metric._get_or_create(
File "openwisp_monitoring/monitoring/base/models.py", line 164, in _get_or_create
metric.save()
File "django/db/models/base.py", line 739, in save
self.save_base(using=using, force_insert=force_insert,
File "django/db/models/base.py", line 776, in save_base
updated = self._save_table(
File "django/db/models/base.py", line 881, in _save_table
results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
File "django/db/models/base.py", line 919, in _do_insert
return manager._insert(
File "django/db/models/manager.py", line 85, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "django/db/models/query.py", line 1270, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "django/db/models/sql/compiler.py", line 1416, in execute_sql
cursor.execute(sql, params)
File "django/db/backends/utils.py", line 66, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "django/db/backends/utils.py", line 75, in _execute_with_wrappers
return executor(sql, params, many, context)
File "django/db/backends/utils.py", line 79, in _execute
with self.db.wrap_database_errors:
File "django/db/utils.py", line 90, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "django/db/backends/utils.py", line 84, in _execute
return self.cursor.execute(sql, params)
We could try catching this error and try the read query again, maybe the object has already been created by another background task which ran in parallel.
I have observed a lot of errors like the following, coming from
openwisp_monitoring.device.tasks.write_device_metrics:We could try catching this error and try the read query again, maybe the object has already been created by another background task which ran in parallel.