I have a django app with redis which is currently used as the broker for Celery, and nothing beyond that.
I would like to utilize it further for lookup caching.
Let's say I had a widely used table in my database that I keep hitting for lookups. For the same of example, let's say it's a mapping of U.S. zip codes to city/state names, or any lookup that may actually change over time that's important to my application.
My questions are:
Once the server starts (in my case, Gunicorn), how do I one-time load the data from the database table to Redis. I mean- where and how do I make this one time call? Is there a place in the django framework for such "onload" calls? or do I simply trigger it lazy-style, upon the first request which will be served from the database, but trigger a Redis load of the entire table?
What about updates? If the database table is updated somehow, (e.g. row deleted, row updated, row added) how do I catch that in order to update the Redis representation of it?
Is there a best-practice or library already geared toward exactly that?
how do I one-time load
For the one time load you can find answer here (from those answers only urls.py worked for me). But I prefer another scenario. I would create manage command and I would add this script to the command you start your Gunicorn. For example if you're using systemd you could add this to service service config. You can also combine those, like add command and call it from urls.py
What about updates
It really depends on your database. For example if you use postgresql, you can create trigger for update/insert/delete and external table as redis. Also django has signal mechanism so you can implement that in django as well. You can also write your custom wrapper. In this wrapper you implement you operations + syncing with redis. And you would call wrapper instead of. But I prefer the first scenario.
Is there a best-practice or library already geared toward exactly that?
Sorry I can't help you with this one.