#35685: Connection Pooling Not Working with psycopg3 in Django
------------------------+-----------------------------------------
Reporter: tsw025 | Type: Uncategorized
Status: new | Component: Uncategorized
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
------------------------+-----------------------------------------
We are encountering issues with database connection pooling in Django when
using psycopg3. The connections are being closed after each request,
preventing effective pooling. Attempting to set CONN_MAX_AGE to a value
greater than 0 results in an ImproperlyConfigured error, indicating that
"Pooling doesn't support persistent connections."
Steps to Reproduce:
Configure Django to use psycopg3 with PostgreSQL.
Set CONN_MAX_AGE to a value greater than 0 in the DATABASES settings.
Observe that connections are closed after each request and pooling is not
functioning as expected.
Expected Behavior:
Database connections should persist and be reused across requests
according to the pooling configuration.
Actual Behavior:
Connections are closed after each request, and an error is raised when
setting CONN_MAX_AGE to a non-zero value.
Configuration:
Python 3.10
Django 5.1
psycopg3 3.2.1 (with pooling enabled)
PostgreSQL
Config:
{{{
RDS_DB_ENGINE = "django.db.backends.postgresql"
if USE_SSL and not TESTING:
OPTIONS = {
"sslmode": "verify-full",
"sslrootcert": SECURE_RDS_CERTIFICATE_FILE,
"pool": True
}
else:
OPTIONS = {
"sslmode": "disable",
}
DATABASES = {
"default": {
"ENGINE": IAM_DB_ENGINE if USE_RDS_IAM_AUTH else RDS_DB_ENGINE,
"NAME": RDS_DB_NAME,
"USER": RDS_DB_USER,
"PASSWORD": RDS_DB_PASSWORD,
"HOST": RDS_HOST,
"PORT": RDS_PORT,
"OPTIONS": OPTIONS,
},
"read-db": {
"ENGINE": IAM_DB_ENGINE if USE_RDS_IAM_AUTH else RDS_DB_ENGINE,
"NAME": RDS_DB_NAME,
"USER": RDS_DB_USER,
"PASSWORD": RDS_DB_PASSWORD,
"HOST": RDS_READ_HOST,
"PORT": RDS_READ_PORT,
"OPTIONS": OPTIONS,
},
}
}}}
Error and Pooling Logic: Django.db.backends.postgres.base
{{{
@property
def pool(self):
pool_options = self.settings_dict["OPTIONS"].get("pool")
if self.alias == NO_DB_ALIAS or not pool_options:
return None
if self.alias not in self._connection_pools:
if self.settings_dict.get("CONN_MAX_AGE", 0) != 0:
raise ImproperlyConfigured(
"Pooling doesn't support persistent connections."
)
# Set the default options.
if pool_options is True:
pool_options = {}
}}}
Connection Close Logic:Django.db.backends.base.base
{{{
max_age = self.settings_dict["CONN_MAX_AGE"]
self.close_at = None if max_age is None else time.monotonic() + max_age
def close_if_unusable_or_obsolete(self):
if self.connection is not None:
self.health_check_done = False
if self.get_autocommit() != self.settings_dict["AUTOCOMMIT"]:
self.close()
return
if self.errors_occurred:
if self.is_usable():
self.errors_occurred = False
self.health_check_done = True
else:
self.close()
return
if self.close_at is not None and time.monotonic() >=
self.close_at:
self.close()
return
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/35685>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/010701915cea0f3b-8c815710-3109-40db-8822-dec4f569b36c-000000%40eu-central-1.amazonses.com.
