Software Architect's Handbook

Using a private caching strategy

A private cache is held on the machine that is running the application that is using it. If multiple instances of an application are running on the same machine, then each application instance can have its own cache.

One of the ways that data is stored in a private cache is in-memory, which makes it extremely fast. If there is a need to cache more data than can fit in the amount of memory available on the machine, then cached data can be stored on the local file system.

In a distributed system using the private caching strategy, each application instance will have its own cache. This means that it is possible for the same query to yield different results depending on the application instance.