django-db-connection-retrier

Django Database Connection Retrier

Automatically try to re-establish Django database connections when they fail due to DNS errors.

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When the Django app (dbconnectionretrier) loads, a hook is installed in Django's BaseDatabaseWrapper.ensure_connection that catches django.db.OperationalError. If the error raised is a DNS error, the connction attempt is retried synchronously three times.

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Tested on Django 2.0-2.3 and Python 3.7 and 3.8. Might work with other versions of Django and Python.

Installation

1. Install the package from PyPi:

    $ pip install django-db-connection-retrier
   

2. Add dbconnectionretrier to your INSTALLED_APPS:

    INSTALLED_APPS = [
        'dbconnectionretrier',
        ...
    ]
   

Manual usage

Adding dbconnectionretrier to INSTALLED_APPS enables automatic connection retrying. Want more granular control over patching?

Globally

from dbconnectionretrier.patch import patch_ensure_connection

# after this line executes, connection retrying is enabled
patch = patch_ensure_connection()

# after this line, the connection retrying is disabled
patch.rollback()

Context manager

from dbconnectionretrier.patch import patch_ensure_connection_contextual

with patch_ensure_connection_contextual():
    # all code inside this block benefits from connection retrying