We changed auth.py to import from app.serialised_models here:
https://github.com/alphagov/notifications-api/pull/2887/files#diff-77cbb1e03185c7319f0311371c438b0cR11
`serialised_models.py` imports from `templates_dao.py`
`templates_dao.py` imports from `users_dao.py`
`users_dao.py` imports from `errors.py`
`errors.py` imports from `auth.py` … and the circle is complete 💥
For some reason this caused the Celery workers to crash on startup, but
not the app. Which I guess is why the integration tests didn’t catch
this?
Same as we’re doing for templates.
This means avoiding a database call, even for services that don’t hit
our API so often.
They’ll still need to go to the database for the API keys, because we’re
not comfortable putting the API key secrets in Redis.
But once a service has got its keys from the database we commit the
transaction, so the connection can be freed up until we need it again to
insert the notification.
Same as we’ve done for templates.
For high volume services this should mean avoiding calls to external
services, either the database or Redis.
TTL is set to 2 seconds, so that’s the maximum time it will take for
revoking an API key or renaming a service to propagate.
Some of the tests created services with the same service ID. This
caused intermittent failures because the cache relies on unique service
IDs (like we have in the real world) to key itself.
We think that holding open database transactions while we go and do
something else is causing us to have poor performance.
Because we’re not serialising everything as soon as we pull it out of
the database we can guarantee that we don’t need to go back to the
database again.
So let’s see if explicitly closing the transaction helps with
performance.
By serialising these straight away we can:
- not go back to the database later, potentially closing the connection
sooner
- potentially cache the serialised data, meaning we don’t touch the
database at all
For some reason our V1 get template response wraps the whole template in
a dictionary with one key, `'data'`:
0d99033889/app/template/rest.py (L166)
That means when the admin app caches the response it also caches it in
this format.
The API needs to do the same, otherwise it will be cacheing data with a
schema that the admin app isn’t expecting, and vice-versa.
