- Redis also does cache information but has got additional features like persistence and replication
- Redis does not support the functionality of LRU (least recently used) eviction of values
- In Redis you can set a time out on everything when memory is full, it will look at three random keys and deletes the one which is closest to expiry
- Redis does not support CAS ( Check and Set). It is useful for maintaining cache consistency
- Redis has got stronger data structures; it can handle strings, binary safe strings, list of binary safe strings, sorted lists, etc.
- Redis had a maximum of 2GB key length
- Redis is single threaded
- Memcached only cache information.
- Memcached supports the functionality of LRU (least recently used) eviction of values
- In Memcached when they overflow memory, the one you have not used recently (LRU- least recently used) will get deleted
- Memcached supports CAS (Check and Set)
- In Memcached, you have to serialize the objects or arrays in order to save them and to read them back you have to un-serialize them.
- Memcached had a maximum of 250 bytes length
- Memcached is a multi-threaded