Simple server side cache for Express.js with Node.js
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This document discusses server-side caching for web applications using Express.js and Node.js. It defines caching as storing dynamically generated data for reuse to improve performance. Caching works by storing response data in memory or on disk so subsequent identical requests can be served from cache rather than re-generating the response. The document outlines the benefits of caching like better performance, scalability and robustness. It also covers caching terminology, different caching types, and how to implement caching using file system caching or in-memory caches like Memcached and Redis.
![Caching
Terminology
[ Cache Hit ]
when requested data is contained in the cache
[ Cache Miss ]
when requested not in the cached, has to be
recomputed or fetched from original storage
[ Cache Key ]
unique identifier for a data item in the cache
[ Expiration ]
item expires at a specific date (absolute),
specifies how long after an item was last
accessed that is expires (sliding)
[ Backing store ]
persist cached data on disk
[ Cache Scavenging ]
deleting items from the cache when
memory is scarce
[ Local Cache ]
caching data on clients rather than on
servers
[ Distributed Cache ]
extension of the traditional concept
of cache that may span multiple
servers](https://image.slidesharecdn.com/server-side-cache-express-170721060712/85/Simple-server-side-cache-for-Express-js-with-Node-js-10-320.jpg)
![How to use?
[ File System Caching ]
➔ It works without any
additional server. Most of the
CMS by default use file cache
without any configurations.
[ In-Memory Caching ]
➔ Need to install and configure
cache server
➔ Need client library to access
cache
➔ Most of the popular
framework has very good
built-in or third-party library.](https://image.slidesharecdn.com/server-side-cache-express-170721060712/85/Simple-server-side-cache-for-Express-js-with-Node-js-17-320.jpg)
Simple server side cache for Express.js with Node.js
- 1. Simple server side cache for Express.js with Node.js
- 4. What is caching? Caching is a commonly used technique to improve the performance of any application, be it desktop, mobile or web. When dealing with web applications we can make good use of client-side caching using response headers that all browsers currently support.
- 5. What is caching in web application? Web application caching is the process of storing dynamically generated data for reuse and leaving data closer to the end user.
- 7. Traditional Data Query (Without Cache) Query Get Rows From Database Return Rows to Application
- 8. Cached Data Query Query Data In Cache Get Rows From Database Return Row to Application Insert Rows Into Cache Cache Storage Database Yes No
- 9. Why we use? ➔ Better performance ◆ System loads faster/better responsiveness ➔ Better scalability ◆ Limit bottlenecks in a system ➔ Better robustness ◆ Can support more load
- 10. Caching Terminology [ Cache Hit ] when requested data is contained in the cache [ Cache Miss ] when requested not in the cached, has to be recomputed or fetched from original storage [ Cache Key ] unique identifier for a data item in the cache [ Expiration ] item expires at a specific date (absolute), specifies how long after an item was last accessed that is expires (sliding) [ Backing store ] persist cached data on disk [ Cache Scavenging ] deleting items from the cache when memory is scarce [ Local Cache ] caching data on clients rather than on servers [ Distributed Cache ] extension of the traditional concept of cache that may span multiple servers
- 11. Advantages ❖ Speed up application ❖ Less Resources Used ❖ Reuse content Disadvantages ❖ Stale Data ❖ Overhead ❖ Complexity
- 12. Type Of Caching ❑ Client Caching - browser caches URLs for future uses - Mozilla Firefox, Google Chrome ❑ Proxy Caching - proxy server caches most requested URLs - Varnish ( reverse proxy ) - CDN ( forward proxy ) ❑ Server-side Caching - server side cache reduces load on server - File System Cache - In-Memory Cache (MemCached, Redis)
- 13. File Cache A file of data on a local hard drive. When downloaded data are temporarily stored on the user's local disk or on a local network disk, it speeds up retrieval the next time the user wants that same data (Web page, graphic, etc.) from the Internet or other remote source.
- 14. In-Memory means We are Bound By RAM
- 15. MemCached Memcached is an in-memory key- value store for small chunks of arbitrary data (strings, objects) from results of database calls, API calls, or page rendering.
- 16. Redis Redis is an open source, advanced key-value store. It is often referred to as a "data structure server" since keys can contain strings, hashes, lists, sets and sorted sets.
- 17. How to use? [ File System Caching ] ➔ It works without any additional server. Most of the CMS by default use file cache without any configurations. [ In-Memory Caching ] ➔ Need to install and configure cache server ➔ Need client library to access cache ➔ Most of the popular framework has very good built-in or third-party library.