Question: What are Memcached and Redis?


Memcached and Redis are open-source, in-memory data stores that are widely used for caching purposes. They both provide high-performance, low-latency access to frequently accessed data, which helps speed up web applications, reduce database load, and improve overall scalability.


Memcached is a distributed memory caching system that stores key-value pairs in memory. It was originally developed by Brad Fitzpatrick at LiveJournal in 2003 and has since become one of the most widely used caching systems on the internet.

Here's an example of how to use memcached in Python:

import memcache # Connect to a local instance of memcached mc = memcache.Client(['']) # Set a key-value pair mc.set('my_key', 'my_value') # Get a value by key value = mc.get('my_key') print(value)


Redis (which stands for Remote Dictionary Server) is an in-memory data store that supports a wide variety of data structures, including strings, hashes, lists, sets, and more. It was created by Salvatore Sanfilippo in 2009 and has quickly gained popularity due to its versatility and performance.

Here's an example of how to use Redis in Python using the popular Redis-py library:

import redis # Connect to a local instance of Redis r = redis.Redis(host='localhost', port=6379, db=0) # Set a key-value pair r.set('my_key', 'my_value') # Get a value by key value = r.get('my_key') print(value)

Both Memcached and Redis have their own strengths and weaknesses and are suitable for different use cases. Memcached is great for simple key-value caching, while Redis supports more complex data types and has built-in support for features like publish/subscribe messaging and transactions.

Was this content helpful?

White Paper

Free System Design on AWS E-Book

Download this early release of O'Reilly's latest cloud infrastructure e-book: System Design on AWS.

Free System Design on AWS E-Book

Start building today

Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.