Redis可以执行Memcached提供的所有内容（LRU缓存，项目到期，现在已经在版本3.x +中进行集群，目前处于测试阶段），或者像twemproxy这样的工具。 表现也是相似的。 更重要的是，Redis添加了持久性，因为在服务器重新启动时您不需要进行缓存升级。 
 
 参考一些比较Redis和Memcache的旧答案，其中有些则赞成Redis替代Memcache（如果已经存在于堆栈中）： 
 
 
 
 Memcached vs. Redis？ 
 
 
 与Redis相比，memcached是一只恐龙吗？ 
 
 
 Redis和Memcache还是Redis？ 
 
 
 尽管如此，在研究诸如Instagram，Pinterest，Twitter等大型网页规模公司的堆栈时，我发现他们使用Memcached和Redis来实现不同的目的，而不是使用Redis进行主缓存。 主缓存仍然是Memcached，Redis用于其基于逻辑缓存的数据结构。 
 
 截至2014年，为什么memcached仍然值得将其作为附加组件添加到堆栈中，当您已经拥有可以完成memcached可以执行的所有操作的Redis组件时？ 有哪些优点使建筑师/工程师仍然将memcached与已经存在的Redis分开？ 
 
 更新： 
 
 对于我们的平台，我们完全丢弃了Memcached，并且将redis用于简单的逻辑缓存要求。 高性能，灵活可靠。 
 
 一些示例场景： 
 
 
 
 按特定模式列出所有缓存的密钥，并读取或删除其值。 很容易在redis，不可行（容易）在memcached。 
 
 
 存储一个有效载荷超过1mb，容易做到redis，需要在memcached的平板大小的调整，这具有自己的性能副作用。 
 
 
 当前缓存内容的简单快照 
 
 
 Redis集群以及语言驱动程序以及生产准备以及集群部署也很容易。 
 

Redis can do everything that Memcached provides (LRU cache, item expiry, and now clustering in version 3.x+, currently in beta) or by tools like twemproxy. The performance is similar too. Morever, Redis adds persistence due to which you need not do cache warming in case of a server restart.
 
Reference to some old answers which compare Redis and Memcache, some of which favor Redis as replacement of Memcache (if already present in the stack):
 
 
 
Memcached vs. Redis?
 
 
Is memcached a dinosaur in comparison to Redis?
 
 
Redis and Memcache or just Redis?
 
 
In spite of this, on studying stacks of large web scale companies like Instagram, Pinterest, Twitter etc, I found that they use both Memcached and Redis for different purposes, not using Redis for primary caching. The primary cache is still Memcached, and Redis is used for its data structures based logical caching.
 
As of 2014, why is memcached still worth the pain to be added as additional component into your stack, when you already have a Redis component which can do everything that memcached can? What are the favorable points that incline the architects/engineers to still include memcached apart from already existing Redis?
 
Update :
 
For our platforms, we have completely discarded Memcached, and use redis for plain as well as logical caching requirements. Highly performant, flexible and reliable.
 
Some example scenarios:
 
 
 
Listing all cached keys by a specific pattern, and read or delete their values. Very easy in redis, not doable ( easily ) in memcached.
 
 
Storing a payload more than 1mb, easy to do in redis, requires slab size tweaks in memcached, which has performance side effects of its own.
 
 
Easy snapshots of current cache content
 
 
Redis cluster is production ready as well along with language drivers,hence clustered deployment is easy too.
 

原文：https://stackoverflow.com/questions/23601622