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Difference between memcache and Redis

What is the difference between memcache and Redis Internal design also for both.


Course: Grokking the Principles and Practices of Advanced System Design - Learn Interactively
Lesson: Estimations and Limitations of a Many-Core System - Grokking the Principles and Practices of Advanced System Design

Hi @Ashwani,
Both Memcache and Redis are in-memory caching systems, but they have different internal designs:

Memcache: Memcached is a simple key-value store that stores data in a hash table. When data is added to Memcached, it is broken down into a key-value pair and hashed to a specific location in the hash table. Memcached uses a single-threaded architecture, so it can only process one request at a time.
Redis: Redis is more than just a key-value store. It is also a data structure server that supports a wide range of data structures such as strings, hashes, lists, sets, and sorted sets. Redis uses a more complex architecture that includes multiple threads and an event loop. Data is stored in a dictionary-like data structure called a Redis database. When data is added to Redis, it is serialized and stored in memory.

Redis also provides some advanced features that are not available in Memcached, such as:

  • Persistence: Redis can persist data to disk to protect against data loss in the event of a server failure.
  • Replication: Redis can replicate data to multiple servers to improve availability and performance.
  • Pub/Sub messaging: Redis can be used as a messaging system, with the ability to publish messages to channels and subscribe to receive messages.

Overall, while Memcache is a simple and lightweight caching solution, Redis provides a more complex and feature-rich caching system that can support a wide range of use cases.

I hope this helps.