A, Redis Introduction
Redis is an open source (BSD license) to use ANSI
C language
prepared to support the network, based on the persistence of memory can log type, Key-Value
database
API, proxy caching and message queues, and available in multiple languages. From March 15, 2010, Redis development work was hosted by VMware. From May 2013 began, Redis development sponsored by Pivotal.
It is often called a data structure of the server, since the (value) can be a string (String), a hash (the hash), a list (List), a collection (set) and the ordered set (sorted sets) and other types. Built-in replication, Lua script, LRU recovery, transaction and different levels of persistent disk function, while providing high availability by redis Sentinel, provides automatic partitioning by Redis Cluster.
Two, Redis Introduction
Redis is completely open source and so free, to comply with the BSD license, it is a high-performance key-value database.
Redis key-value cache and other products have the following three features:
- Redis supports data persistence, data in memory can be saved to disk, reboot to load when you can be reused.
- Redis only supports simple key-value data types, while also providing list, set, zset, hash and other data storage structure.
- Redis supports backup data, i.e., data backup master-slave mode.
Three, Redis advantage
- High performance -Redis can read as fast as 110,000 times / s, write speed is 81000 times / s.
- Rich data types -Redis support binary case Strings, Lists, Hashes, Sets and Ordered Sets the data type of the operation
- All operations are atomic -Redis atomic, meaning that either succeed or fail completely executed execution. It is a single atomic operation. A plurality of operation also supports transaction, i.e. atomicity, and EXEC instructions by MULTI wrap.
- Feature-rich -Redis also support publish / subcribe, notice, key expiration and so on characteristics.
Four, Redis and other key-value store What is the difference?
- Redis has a more complex data structure and provide atomic operations on them, which is different from the other databases evolutionary path. At the same time Redis data types are based on the basic data structure transparent to the programmer, without the need for additional pumping that
- Redis running in memory but can be persisted to disk, so when the high-speed read and write different data sets need to weigh memory, because the amount of data can not rain hardware memory. Another advantage of in-memory databases are, compared to the same complex data structures, operate in a very simple memory on the disk, so you can do a lot of internal Redis highly complex matter. Meanwhile, in terms of their compact disk format to generate additional way, because they do not require random access.