How to understand redis

redis is a key-value storage system. Similar to Memcached, it supports relatively more stored value types, including string (string), list (linked list), set (set), zset (sorted set - ordered set) and hash (hash type). (Recommended: "redis video tutorial")

These data types support push/pop, add/remove, intersection, union, difference and richer operations, and these operations It's all atomic. On this basis, redis supports various different ways of sorting. Like memcached, data is cached in memory to ensure efficiency.

The difference is that redis will periodically write updated data to disk or write modification operations to additional record files, and on this basis, master-slave (master synchronized from).

Redis is a high-performance key-value database. The emergence of redis has largely compensated for the shortcomings of key/value storage such as memcached, and can play a very good supplementary role to relational databases in some situations.

It provides Java, C/C, C#, PHP, JavaScript, Perl, Object-C, Python, Ruby, Erlang and other clients, which is very convenient to use.

Redis supports master-slave synchronization. Data can be synchronized from the master server to any number of slave servers, and the slave server can be a master server associated with other slave servers. This allows Redis to perform single-level tree replication. Saving can write data intentionally or unintentionally.

Since the publish/subscribe mechanism is fully implemented, when the slave database synchronizes the tree anywhere, it can subscribe to a channel and receive the complete message release record of the master server. Synchronization is helpful for scalability and data redundancy of read operations.

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