Should you trust Redis to keep your data safe?

Question

Redis

Can Redis be trusted to store data as practically the primary storage? For example in Memcached or file cache, we usually check for the existence of data, and if it doesn't exist, pull it from a database like MySql and save it again. Can Redis guarantee data persistence and availability? Is it possible, for example, not to store data like categories in the main database, but always use Redis to store them?
Those. probably, the question is rather about what radishes can be useful for at all.

Answer 1

I once asked a ± similar question Redis vs Elasticsearch vs Sphinx for data storage and searching?
There, in one of the solutions, they suggested the universal tool Manticore Search, although I haven’t tested it yet

Answer 2

Can Redis guarantee data integrity and availability?

I view Redis as a snapshot-recoverable cache. With some probability, the data will be saved (not guaranteed). The data is reset periodically as a delta.
https://redis.io/topics/persistence

Is it possible, for example, not to store data like categories in the main database, but always use Redis to store them?

It is possible, but I do not recommend using it as the main DBMS. While it scales well, RAM is much more expensive than SSDs. As a result, you will have to pay bills for memory-heavy servers with multiple Redis instances.
https://stackoverflow.com/a/42677671

What are radishes good for?

For storing data that needs frequent access: a cache of short-lived keys.