Caching

Storing items which are frequently accessed in a memory cache, is one definitive way to improve performance (latency) exponentially rather than accessing from disk.

Sample Cache Usage in system

Why do we use cache?

• Cache improves the overall performance of the system. (latency and throughput)
• Example: Facebook prepares the user’s main page in advance and stores in a cache located geographically close to the user. This approach ensures faster page-load of the main page.

How the cache improves performance?

• Some items are likely to be accessed more often than others, so if we store these items where it can be accessed faster, we can improve performance considerably.
• The cache generally uses memory and is 10x - 100x times faster than persistent storage