Memcached Vs Redis



When someone needs to enhance the execution and speed of their data-driven web applications, the primary activity is to have a proper caching system and for which Memcached and Redis instantly come to mind. Both distributed caching systems are used to boost the speed of database-driven websites. They cache the data and objects in the RAM to retrieve data so that they are easily accessible as opposed to going to external data sources like database or API. To pick the right one for their web applications, one should know the basic differences between these two data engines.

Memcached Architecture

Memcached Architecture

Redis Architecture

Redis Architecture

Similarities between Memcached & Redis:

  • These two most popular open-source and in-memory data stores are easy to use and offer high performance. While Redis offers a rich set of features that make it effective for a wide range of use cases as compared to Memcached which is designed for simplicity.
  • Both data engines utilize NoSQL data management solutions and keep data in the RAM for easy and quick fetching which makes them supremely useful as a caching layer. Both are lightning fast in their speed performance. Both work on the similar throughput and latency properties.
  • In 2003, Brad Fitzpatrick developed Memcached for the LiveJournal website. Since then, Memcached has been rewritten in C as the original implementation was in Perl and put in the public domain, where it has become a cornerstone of modern Web applications. Current development of Memcached is based on stability and optimizations rather than adding new features.
  • Salvatore Sanfilippo created Redis in 2009 and he still remains the lead developer of the project to today. Redis is developed to overcome all the shortcomings on Memcached and still, it is maintaining all the features for which Memcached is popular. In fact, Redis has a bit more additional features for which it is considered to be more powerful and useful than Memcached.

Both data engines are used by many companies and in countless mission-critical production environments. These two are supported by client libraries in every conceivable programming language and it is included in a multitude of packages for developers. In fact, it’s a rare web stack that does not include built-in support for either Memcached or Redis.

Differences Between Memcached vs Redis –
Redis Vs Memcached Table Image

Memcached vs Redis

1.Read-Write Speed:
The overall speed in data management is determined by Read-Write Speed. Both the data engines have immensely high speed as anyone can expect but Redis edges over Memcached slightly. Memcached clearly outstands Redis in the region when it comes to handling high traffic websites that are database driven.

Memcached stores data in its memory directly and retrieves required data directly from its memory rather than visiting the source database whereas Redis itself is a database that is residing in its memory. It has the same method as a database like a key-value pair for storing and retrieving data. To have real-time metrics and analytics, Redis is the best option for you.

3.Data Structure:
Memcached uses only string and integer to store data in its memory. The integers allow only addition and subtraction data manipulation. There is no scope for arrays, objects, and other widely used data structures. Saving them is hectic, and it makes the process slow. Redis takes care of the problem and has data structures like binary safe strings, list, set, sorted set along with string an integer.

Replication is considered to be a big factor in any data storage system. Unfortunately which is not supported by Memcached and there has been no improvement on that front. To increase the speed Memcached is continuously putting effort by optimizing the system but not adding any new features. While on the other hand, Redis supports master-slave replication. The slave servers can have an exact copy of master servers because of which in the time of system failure, the application will not be affected.

For any data storage system, Persistence is another big deciding factor. It is a must-have feature, but Memcached lacks an improved system in comparison to Redis where the data gets synced every two seconds, and there are various options available for controlling the data persistence. It can also be said that even when there is an accidental failure in the application and unplanned shutdown, the data are retrievable but in Memcached, it will be lost instantly. In a cache system, Redis has an upper hand on Memcached as a fact that Redis does have a data persistence and you can turn it on and off as per your requirement, whereas Memcached does not have.

6. Pipelining:
Memcached is efficient in handling high traffic websites because of Pipelining. Memcached includes multi-threading option for attending to multiple requests in parallel contrast to Redis which has an underdeveloped pipelining system, and it needs to improve significantly to catch up with Memcached. On the other hand, Redis provides a constraint limit 512MB to handle large data in comparison to Memcached whose constraint limit is merely 1MB. It is one of the major reasons for Redis to be popular in today’s scenario especially when you need to store the entire page in a cache.


In this article, we have discussed the key differences between Memcached & Redis, comparing with the data-types supported, cluster management, data persistence support, and memory management schemes.

For web applications like For online stores, IoT applications, and real-time analytics Redis is the best caching solution. Redis can boost the page loading time for e-commerce applications because of its full page cache mechanism and you can even store sessions. IoT applications send a lot of data every minute to the web server which is pushed to Redis for processing before transferring to permanent storage. You can use Memcached for its simplicity, better efficiency in handling high traffic, and efficient memory management for rather lightweight database-driven web applications. But in reality, Redis is superior, and Memcached is a subset of Redis.

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