Caching strategies

This week has a task connected with caching, but not usual – we had a db in redis but without backup anywhere. So we have to create writes to db on update, but without adding huge load on db (analytics counters are counting very fast). So decided to make a review of different caching strategies. Feel free to add if I missed something. https://zubialevich.blogspot.com/2018/08/caching-strategies.html