When designing and developing highly available system, cache is an very important consideration. It is useful to cache some frequently accessed data so that they can be accessed quickly and also cache can protect the downstream system like DB from being hit too often. To provide better cache design in large systems, some problems may need to be considered first. In this post, we will talk about some frequently discussed cache problems and mitigation plans.Cache penetrationCache penetration is a scenario where the data to be searched doesn't exist at DB and the returned empty result set is...