One: Features and comparisons1. Performance: Performance is excellent, specific to the details, because Redis only use single core, and memcached can use multi-core, so on average every core redis in the storage of small data than memcached performance higher. In more than 100k of data, Memcached performance is higher than Redis, although Redis has recently been optimized for the performance of storing big data, but it is slightly inferior to Memcached. 2. Memory space and data volume size: memcached can modify the maximum memory, using the LRU algorithm. Redis adds features to the VM, breaking the limits of physical memory. 3. Convenient operation: memcached data structure is single, only used to cache data, Redis support richer data types (most commonly used data types are mainly composed of five kinds: String, Hash, List, set and sorted set), The data can also be manipulated directly on the server side, which reduces network IO times and data volume. 4. Reliability: Memcached does not support data persistence, the data disappears after power outage or reboot, but its stability is guaranteed. Redis supports data persistence and data recovery, allowing single points of failure, but also at the cost of performance. 5. Application Scenario: Memcached: Reduce database load in dynamic system, improve performance, do cache, suitable for reading and writing, big data volume (such as Renren large query user information, friend information, article information, etc.). Redis: It is suitable for high requirements for read/write efficiency, complex data processing business and high security requirements (such as the count of Sina Weibo and Weibo release part of the system, the data security, read and write requirements are very high).
Two: The use of the two need to consider1.Memcached single Key-value size Limited, one value maximum only 1MB, Redis's maximum supported 512mb2.memcached is just a memory cache, no requirement for reliability, and Redis prefers a memory database, so it is 3 more reliable. Essentially, memcached is just a single key-value memory cache, while Redis is a Data structure in memory database, support five types, so redis in addition to simple caching, but also can handle some simple logic operations, Redis can not only cache, And can also be used as a database with 4. The new version (3.0) of Redis refers to cluster distribution, which means that the cluster itself balances client requests, each node can communicate, can expand the line, maintainability more powerful.
Reference: http://www.open-open.com/lib/view/open1409643182369.html
http://blog.163.com/sun_jian_zhang/blog/static/187804041201310795917333/
Differences between Memcached and Redis and their application scenarios
