Description
Django database retries. Main motivation for using this - to deal with network/db issues to avoid data-loss.
Usually when you develop a project locally with a single user - everything works perfectly. Local networks are super-stable, and simultaneous users don't bother you. When it comes to the real world - your application can (and definitely will) face network issues. Second case - deadlocks, which I personally see too often across different projects. And the only possible solution here to avoid the data-loss - to do a query retry.
IMPORTANT: Right now this works ONLY WITH MYSQL. If someone requires postgres/other dbs support - please create an issue
Usage
Install: pip install django-db-retry
Choose your flow (or use both):
- Monkey-patch django internal methods (IMPORTANT: global patching won't handle retries for atomic transactions.
with_query_retry
decorator should be used instead) - Use explicit decorator
Monkey-patch:
Add next code somewhere on the top level of your project
from django_db_retry import install as install_db_retries install_db_retries()
That's it =) All the needed underlying django methods will be wrapped with the retry decorator and will do execution retry if your app will face a network issue or deadlock
Decorator
Can be used on top of any function/view and will do a retry if deadlock/network error will happen. Default number of retries is 5. This value can be configured by using the QueryRetry
class (see example 2):
from django_db_retry import with_query_retry from django.db.transaction import atomic @with_query_retry def some_view(): query_0, query_1 = ... with atomic(): query_0() query_1() return ...
Configuring own value of retries
from django_db_retry import QueryRetry from django.db.transaction import atomic my_retry_decorator = QueryRetry(max_tries=100) @my_retry_decorator def some_view(): query_0, query_1 = ... with atomic(): query_0() query_1() return ...
Todo
- Deal with atomic transactions during global patching
- Add possibility to install the package using django
INSTALLED_APPS
settings