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Database / REDIS

Difference between Memcached and REDIS.

Memcached.REDIS.
Memcached is multi-threaded. Redis is single threaded.
Memcached only does caching information. Redis does caching information and also supports persistence and replication.
Memcached supports the functionality of LRU (Least Recently Used) eviction of values.Redis does not support the functionality of LRU eviction of values.
In Memcached when they overflow memory, the one you have not used recently (LRU- Least Recently Used) will get deleted. 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.
Memcached supports CAS(Check And Set). It is useful for maintaining cache consistency. Redis does not support CAS ( Check And Set).

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