Caching Strategies

5 Strategies for Managing Cache Space

Cache management strategies are used to determine which data to keep in the cache and which data to remove when the cache is full and needs to make room for new data. There are several strategies for managing cache space.

Least-Recently Used (LRU)

Least-Recently-Used (LRU) caching strategy removes the data that was least recently accessed from the cache to make room for new data. The assumption is that data that has not been accessed for a long time is less likely to be accessed again in the near future.

The Least-Recently-Used (LRU) caching strategy removes the data that was least recently accessed from the cache to make room for new data.
The Least-Recently-Used (LRU) caching strategy removes the data that was least recently accessed from the cache to make room for new data.

Least-Frequently Used (LFU)

The Least-Frequently-Used (LFU) strategy removes the data that has been accessed the fewest number of times from the cache. The idea is that data that doesn’t get used very often won’t be used again in the near future.

The Least-Frequently-Used (LFU) strategy removes the data that has been accessed the fewest number of times from the cache.
The Least-Frequently-Used (LFU) strategy removes the data that has been accessed the fewest number of times from the cache.

First-In, First-Out (FIFO)

The First-In, First-Out (FIFO) caching strategy removes the data that was added to the cache first to make room for new data. The assumption is that the data that has been in the cache the longest is less likely to be accessed again soon.

The First-In, First-Out (FIFO) caching strategy removes the data that was added to the cache first to make room for new data.
The First-In, First-Out (FIFO) caching strategy removes the data that was added to the cache first to make room for new data.

Last-In, First-Out (LIFO)

The Last-In, First-Out (LIFO) strategy removes the data that was added to the cache most recently to make room for new data. The assumption is that the data that was most recently added is the least likely to be accessed again.

The Last-In, First-Out (LIFO) strategy removes the data that was added to the cache most recently to make room for new data.
The Last-In, First-Out (LIFO) strategy removes the data that was added to the cache most recently to make room for new data.

Random Replacement

The Random Replacement caching strategy takes data out of the cache at random to make room for new information. This should only be used if your data access patterns align with several of the above strategies, making none of them ideal for your environment, so using the simplest strategy would be a reasonable choice.

The Random Replacement caching strategy takes data out of the cache at random to make room for new information.
The Random Replacement caching strategy takes data out of the cache at random to make room for new information.

The choice of cache management strategy will depend on the nature of the data being cached and the characteristics of the application that is using the cache. Some types of data or applications may work better with certain caching strategies than with others. In practice, LRU and LFU are the most effective strategies for the most workloads, so analyzing your data access patterns will favor one over the other in your deployment.