#36318: Bad stack trace during rollback
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Reporter: Gordon Wrigley | Type: Uncategorized
Status: new | Component: Uncategorized
Version: 4.2 | Severity: Normal
Keywords: | Triage Stage: Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
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TL;DNR the value of `connection.rollback_exc` is being set in one celery
task and then raised in another later celery task.
I'm on 4.2.20 and I got this stack trace from a celery worker
{{{
UniqueViolation: duplicate key value violates unique constraint
"retain_consumer_firm_id_email_hash_3f1266dc_uniq"
DETAIL: Key (firm_id, email_hash)=(ac90f753-3f10-44f2-af43-b851371c5572,
863397f56c061afbaa0822c9c16ece2b55f2e972) already exists.
File "django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
IntegrityError: duplicate key value violates unique constraint
"retain_consumer_firm_id_email_hash_3f1266dc_uniq"
DETAIL: Key (firm_id, email_hash)=(ac90f753-3f10-44f2-af43-b851371c5572,
863397f56c061afbaa0822c9c16ece2b55f2e972) already exists.
File "data_import/import_from_csv.py", line 1692, in _consumer_from_row
consumer.save()
File "core/models/consumer.py", line 615, in save
return super().save(*args, **kwargs)
File "core/models/firm_user.py", line 197, in save
super().save(update_fields=update_fields, **kwargs)
File "common/models.py", line 900, in save
super().save(*args, **kwargs)
File "django/contrib/auth/base_user.py", line 76, in save
super().save(*args, **kwargs)
File "django/db/models/base.py", line 814, in save
self.save_base(
File "django/db/models/base.py", line 877, in save_base
updated = self._save_table(
File "django/db/models/base.py", line 1020, in _save_table
results = self._do_insert(
File "django/db/models/base.py", line 1061, in _do_insert
return manager._insert(
File "django/db/models/manager.py", line 87, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "django/db/models/query.py", line 1805, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "django/db/models/sql/compiler.py", line 1822, in execute_sql
cursor.execute(sql, params)
File "django/db/backends/utils.py", line 67, in execute
return self._execute_with_wrappers(
File "django/db/backends/utils.py", line 80, in _execute_with_wrappers
return executor(sql, params, many, context)
File "django/db/backends/utils.py", line 84, in _execute
with self.db.wrap_database_errors:
File "django/db/utils.py", line 91, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "django/db/backends/utils.py", line 89, in _execute
return self.cursor.execute(sql, params)
TransactionManagementError: An error occurred in the current transaction.
You can't execute queries until the end of the 'atomic' block.
File "celery/app/trace.py", line 760, in __protected_call__
return self.run(*args, **kwargs)
File "common/tasks.py", line 19, in wrapper
return func(*args, **kwargs)
File "contextlib.py", line 81, in inner
return func(*args, **kwds)
File "product_selection/tasks.py", line 129, in try_product_import
product_import.save()
File "common/models.py", line 900, in save
super().save(*args, **kwargs)
File "django/db/models/base.py", line 814, in save
self.save_base(
File "django/db/models/base.py", line 877, in save_base
updated = self._save_table(
File "django/db/models/base.py", line 990, in _save_table
updated = self._do_update(
File "django/db/models/base.py", line 1054, in _do_update
return filtered._update(values) > 0
File "django/db/models/query.py", line 1231, in _update
return query.get_compiler(self.db).execute_sql(CURSOR)
File "django/db/models/sql/compiler.py", line 1984, in execute_sql
cursor = super().execute_sql(result_type)
File "django/db/models/sql/compiler.py", line 1562, in execute_sql
cursor.execute(sql, params)
File "django/db/backends/utils.py", line 67, in execute
return self._execute_with_wrappers(
File "django/db/backends/utils.py", line 80, in _execute_with_wrappers
return executor(sql, params, many, context)
File "django/db/backends/utils.py", line 83, in _execute
self.db.validate_no_broken_transaction()
File "django/db/backends/base/base.py", line 531, in
validate_no_broken_transaction
raise TransactionManagementError(
}}}
There's two related problems with this. First the lines around `File
"data_import/import_from_csv.py", line 1692, in _consumer_from_row` look
like this
{{{
try:
with transaction.atomic():
consumer.save()
if change_log:
self.record_log(consumer, change_log)
except IntegrityError:
}}}
So that has been well handled and the transaction is good again.
Secondly there is no relationship between the `File
"product_selection/tasks.py", line 129, in try_product_import` code path
from the `TransactionManagementError` and the `File
"data_import/import_from_csv.py", line 1692` in _consumer_from_row` code
path from the `IntegrityError` and `UniqueViolation`, these are totally
unrelated celery tasks.
It looks for all intents as if the stack for the
`IntegrityError`/`UniqueViolation` has been captured in one celery task
and then raised in a different later celery task.
Digging through the code and adding prints supports this view.
1. `connection.rollback_exc` is never cleared anywhere
2. `Atomic.__exit__` can set `connection.needs_rollback = True` when it
wasn't true already and without setting `connection.rollback_exc` this
creates the possibility for the observed behaviour.
I'm not sure how critical it is to reproduction, but the actual error that
killed the transaction looks like this
{{{
decimal.InvalidOperation: [<class 'decimal.ConversionSyntax'>]
File "django/db/models/fields/__init__.py", line 1741, in to_python
decimal_value = decimal.Decimal(value)
django.core.exceptions.ValidationError: ['“3 3 3 2 1” value must be a
decimal number.']
File "product_selection/tasks.py", line 123, in try_product_import
Product.objects.bulk_create(new_products, skip_save_logic=True)
File "django/db/models/manager.py", line 87, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
File "common/models.py", line 772, in bulk_create
return super().bulk_create(*args, **kwargs)
File "django/db/models/query.py", line 786, in bulk_create
returned_columns = self._batched_insert(
File "django/db/models/query.py", line 1831, in _batched_insert
self._insert(
File "django/db/models/query.py", line 1805, in _insert
return query.get_compiler(using=using).execute_sql(returning_fields)
File "django/db/models/sql/compiler.py", line 1821, in execute_sql
for sql, params in self.as_sql():
File "django/db/models/sql/compiler.py", line 1747, in as_sql
self.prepare_value(field, self.pre_save_val(field, obj))
File "django/db/models/sql/compiler.py", line 1686, in prepare_value
return field.get_db_prep_save(value, connection=self.connection)
File "django/db/models/fields/__init__.py", line 1760, in
get_db_prep_save
self.to_python(value), self.max_digits, self.decimal_places
File "django/db/models/fields/__init__.py", line 1743, in to_python
raise exceptions.ValidationError(
}}}
My understanding is this should have been captured into `rollback_exc`
when `needs_rollback` was set to True
That happens in `Atomic.__exit__` when `exc_type` is set and
`connection.needs_rollback` is False
I can't test this on 5.2 but `Atomic.__exit__` looks unchanged.
--
Ticket URL: <
https://code.djangoproject.com/ticket/36318>
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