[Django] #35672: Using database connection pooling raises PoolTimeout after a while

[Django]

#35672: Using database connection pooling raises PoolTimeout after a while
-------------------------------------+-------------------------------------
Reporter: Andrioden | Type: Bug
Status: new | Component: Database
| layer (models, ORM)
Version: 5.1 | 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
-------------------------------------+-------------------------------------
I am testing the new db connection pooling, which initially increased the
performance greatly (lowered api response times from 30ms -> 20ms) on my
dev env.

**However, after a while i started getting**
{{{
psycopg_pool.PoolTimeout : couldn't get a connection after 30.00 sec
}}}

It happened after 220 api calls within the span of 7minutes, which
probably means x5-10 database calls.

This forces me to turn of connection pooling.


**Using settings**
{{{
{
"ENGINE": os.environ.get("DB_ENGINE", "django.db.backends.postgresql"),
"OPTIONS": {"pool": True}
}
}}}

**Extra info:**
- Python 3.12.1
- Django 5.1
- psycopg 3.2.1
- psycopg-pool 3.2.2
- Local docker image hosted postgresql database using image "postgres"

**Logs**
{{{
[13/Aug/2024 00:50:41] "POST /api/instances/2/actions/move/ HTTP/1.1" 200
91
couldn't get a connection after 30.00 sec
Traceback (most recent call last):
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 279, in ensure_connection
self.connect()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 256, in connect
self.connection = self.get_new_connection(conn_params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\postgresql\base.py", line 348, in
get_new_connection
connection = self.pool.getconn()
^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\psycopg_pool\pool.py", line 202, in getconn
raise PoolTimeout(
psycopg_pool.PoolTimeout: couldn't get a connection after 30.00 sec

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\ninja\operation.py", line 192, in _run_authentication
result = callback(request)
^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\ninja\security\apikey.py", line 23, in __call__
return self.authenticate(request, key)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\ninja\security\session.py", line 17, in authenticate
if request.user.is_authenticated:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\functional.py", line 251, in inner
self._setup()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\functional.py", line 404, in _setup
self._wrapped = self._setupfunc()
^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\middleware.py", line 37, in <lambda>
request.user = SimpleLazyObject(lambda: get_user(request))
^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\middleware.py", line 17, in get_user
request._cached_user = auth.get_user(request)
^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\__init__.py", line 209, in get_user
user_id = _get_user_session_key(request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\__init__.py", line 62, in
_get_user_session_key
return
get_user_model()._meta.pk.to_python(request.session[SESSION_KEY])
~~~~~~~~~~~~~~~^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\base.py", line 55, in
__getitem__
return self._session[key]
^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\base.py", line 249, in
_get_session
self._session_cache = self.load()
^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\db.py", line 55, in load
s = self._get_session_from_db()
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\db.py", line 34, in
_get_session_from_db
return self.model.objects.get(
^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\manager.py", line 87, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 645, in get
num = len(clone)
^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 382, in __len__
self._fetch_all()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 1928, in _fetch_all
self._result_cache = list(self._iterable_class(self))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 91, in __iter__
results = compiler.execute_sql(
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\cachalot\monkey_patch.py", line 37, in inner
return original(compiler, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\cachalot\monkey_patch.py", line 94, in inner
return execute_query_func()
^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\cachalot\monkey_patch.py", line 80, in <lambda>
execute_query_func = lambda: original(compiler, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\sql\compiler.py", line 1572, in execute_sql
cursor = self.connection.cursor()
^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 320, in cursor
return self._cursor()
^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 296, in _cursor
self.ensure_connection()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 278, in ensure_connection
with self.wrap_database_errors:
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\utils.py", line 91, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 279, in ensure_connection
self.connect()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 256, in connect
self.connection = self.get_new_connection(conn_params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\postgresql\base.py", line 348, in
get_new_connection
connection = self.pool.getconn()
^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\psycopg_pool\pool.py", line 202, in getconn
raise PoolTimeout(
django.db.utils.OperationalError: couldn't get a connection after 30.00
sec
Internal Server Error: /api/instances/2/actions/move/
Traceback (most recent call last):
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 279, in ensure_connection
self.connect()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 256, in connect
self.connection = self.get_new_connection(conn_params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\postgresql\base.py", line 348, in
get_new_connection
connection = self.pool.getconn()
^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\psycopg_pool\pool.py", line 202, in getconn
raise PoolTimeout(
psycopg_pool.PoolTimeout: couldn't get a connection after 30.00 sec

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\core\handlers\exception.py", line 55, in inner
response = get_response(request)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Repos\untitledgame\backend\monitor\middleware.py", line 35, in
__call__
user_id=user_id_or_none(request.user),
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Repos\untitledgame\backend\game\api\utils.py", line 9, in
user_id_or_none
if isinstance(user, AnonymousUser):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\functional.py", line 280, in __getattribute__
value = super().__getattribute__(name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\functional.py", line 251, in inner
self._setup()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\functional.py", line 404, in _setup
self._wrapped = self._setupfunc()
^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\middleware.py", line 37, in <lambda>
request.user = SimpleLazyObject(lambda: get_user(request))
^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\middleware.py", line 17, in get_user
request._cached_user = auth.get_user(request)
^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\__init__.py", line 209, in get_user
user_id = _get_user_session_key(request)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\auth\__init__.py", line 62, in
_get_user_session_key
return
get_user_model()._meta.pk.to_python(request.session[SESSION_KEY])
~~~~~~~~~~~~~~~^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\base.py", line 55, in
__getitem__
return self._session[key]
^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\base.py", line 249, in
_get_session
self._session_cache = self.load()
^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\db.py", line 55, in load
s = self._get_session_from_db()
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\contrib\sessions\backends\db.py", line 34, in
_get_session_from_db
return self.model.objects.get(
^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\manager.py", line 87, in manager_method
return getattr(self.get_queryset(), name)(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 645, in get
num = len(clone)
^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 382, in __len__
self._fetch_all()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 1928, in _fetch_all
self._result_cache = list(self._iterable_class(self))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\query.py", line 91, in __iter__
results = compiler.execute_sql(
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\cachalot\monkey_patch.py", line 37, in inner
return original(compiler, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\cachalot\monkey_patch.py", line 94, in inner
return execute_query_func()
^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\cachalot\monkey_patch.py", line 80, in <lambda>
execute_query_func = lambda: original(compiler, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\models\sql\compiler.py", line 1572, in execute_sql
cursor = self.connection.cursor()
^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 320, in cursor
return self._cursor()
^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 296, in _cursor
self.ensure_connection()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 278, in ensure_connection
with self.wrap_database_errors:
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\utils.py", line 91, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 279, in ensure_connection
self.connect()
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\base\base.py", line 256, in connect
self.connection = self.get_new_connection(conn_params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\utils\asyncio.py", line 26, in inner
return func(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\django\db\backends\postgresql\base.py", line 348, in
get_new_connection
connection = self.pool.getconn()
^^^^^^^^^^^^^^^^^^^
File "C:\Users\andre\.virtualenvs\backend-jnn8gBG-\Lib\site-
packages\psycopg_pool\pool.py", line 202, in getconn
raise PoolTimeout(
django.db.utils.OperationalError: couldn't get a connection after 30.00
sec
[13/Aug/2024 00:56:42] "POST /api/instances/2/actions/move/ HTTP/1.1" 500
235606
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/35672>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.

[Django]

#35672: Using database connection pooling raises PoolTimeout after a while
-------------------------------------+-------------------------------------

Reporter: Andrioden | Owner: (none)
Type: Bug | Status: new
Component: Database layer | Version: 5.1
(models, ORM) |
Severity: Normal | Resolution:

Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Description changed by Andrioden:

Old description:

New description:

I am testing the new db connection pooling, which increased the
performance greatly, typically lowering api response times from 30ms ->
20ms on my dev env.

--
Ticket URL: <https://code.djangoproject.com/ticket/35672#comment:1>

[Django]

#35672: Using database connection pooling raises PoolTimeout after a while
-------------------------------------+-------------------------------------

Reporter: André S. Hansen | Owner: (none)
Type: Bug | Status: closed

Component: Database layer | Version: 5.1
(models, ORM) |

Severity: Normal | Resolution: needsinfo

Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Changes (by Sarah Boyce):

* cc: Florian Apolloner (added)
* resolution: => needsinfo
* status: new => closed

Comment:

Hi Andre, I think we need more information to understand whether/where
Django is at fault here

I believe you have this error because the connection pool is full, this
could mean that Django is not closing connections after using them. For us
to be able to identify where this is happening, can you share a minimal
Django project and steps to reproduce?
--
Ticket URL: <https://code.djangoproject.com/ticket/35672#comment:2>

[Django]

#35672: Using database connection pooling raises PoolTimeout after a while
-------------------------------------+-------------------------------------
Reporter: André S. Hansen | Owner: (none)
Type: Bug | Status: closed
Component: Database layer | Version: 5.1
(models, ORM) |
Severity: Normal | Resolution: needsinfo
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by Florian Apolloner):

Hi André, it would probably help if you enabled the `psycopg.pool` logger
and then check if the connections are returned to the pool properly. Also
what is your request rate and how long are the requests taking? How are
you running the django server? What are the postgresql connection limits?
--
Ticket URL: <https://code.djangoproject.com/ticket/35672#comment:3>

[Django]

#35672: Using database connection pooling raises PoolTimeout after a while
-------------------------------------+-------------------------------------
Reporter: André S. Hansen | Owner: (none)
Type: Bug | Status: closed
Component: Database layer | Version: 5.1
(models, ORM) |
Severity: Normal | Resolution: needsinfo
Keywords: | Triage Stage:
| Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------

Comment (by André S. Hansen):

I did some more testing and figured out the source of the problem. When i
disabled a Threaded connection to the database, the bug stopped happening.
My current theory is that the thread dont return the connection to the
pool. I am investigating now how i should properly do this with Threads.

Simplified version of code

{{{
class TimeMonitorMiddleware(object):
batched_logs: List[RequestLog] = []

def __call__(self, request: WSGIRequest) -> HttpResponse:
# ...

# Save batched logs
if len(self.batched_logs) >= 50:
Thread(target=RequestLog.objects.bulk_create,
args=(batched_logs,)).start()

return response
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/35672#comment:4>