django-redis VS Memcached

Redis is an open-source data-structure store that can be used as a database, cache, message broker, etc. To start using Redis in your Django application, you need to first install the django-redis library. The library makes it easier to connect your Django application to Redis.

To implement caching in Django application. First, set up your Django project and application. Then install django-redis, a project by Jazzband:

django-redis

This isn't such a big deal... There are great third-party packages (i.e https://github.com/jazzband/django-redis) for whoever needs a redis cache backend in a project.

Myself, I just use good ol' memcached for all my caching needs (https://docs.djangoproject.com/en/3.2/topics/cache/#memcache...). It is rock solid and has never failed me till now!

If your example of the counter is accurate for what you want to do, it might be faster using django-redis as your cache backend and using the incr method (which adds one to a given cache key). Repeatedly inserting and deleting database records is much slower than cache operations like that would be. Or is there a way you can avoid deleting database records, and modify existing values?

Memcached

> Multiple clients racing can't be fixed.

Really? You can't think of a single way for multiple clients to operate on the same data without racing? (Here's a hint if you're still having trouble: https://github.com/memcached/memcached/wiki/Commands#cas.)

Memcached: A simple, open-source, distributed memory object caching system primarily used for caching strings. Best suited for lightweight, non-persistent caching needs.

Oh, thank you! I didn't realize that LRU Maintainer Thread was more than an expiration reaper. When it was first being introduced that was its first responsibility as lazy expiration removal by size eviction meant dead entries wasted capacity. It was all work in progress when I had read about it [1] and talked to dormando, so it got fuzzy. The compat code [2, 3] might have also thrown me off if I only looked at the setting and not the usage. Its a neat variant to all of these ideas.

[1] https://github.com/memcached/memcached/pull/97

stores session state in a session store like Memcached or Redis.

memcached has recently gained the ability to spill to disk: https://github.com/memcached/memcached/wiki/Extstore

we recently implemented this to grow our caches to >50TB

Django supports using Memcached as a cache backend. Memcached is a high-performance, distributed memory caching system that can be used to store cached data across multiple servers.