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In this article, we will take a look at the use of redis and the introduction of common data types. There is a certain reference value, friends in need can refer to, hope to help you.

First of all, let's briefly introduce redis.

Redis is a high-performance key-value database. Redis and other key-value cache products have the following three features:

1. Redis supports data persistence. You can save the data in memory on disk and load it again when you restart it.

2. Redis not only supports simple key-value data, but also provides storage of data structures such as list,set,zset,hash.

3. Redis supports data backup, that is, data backup in master-slave mode.

Five uses

1. Full page cache

Full page cache. If you are using server-side rendered content, you do not need to re-render each page for each individual request. With caches such as Redis, you can cache frequently requested content, greatly reducing latency for the most requested pages, and most frameworks have hooks for Redis cached pages.

/ / set full page cache for 1 minute SET key "..." EX 60max / get full page GET key

2. Arrange in order

Because Redis can increment and decrement Set data structures in memory very quickly and efficiently, the performance is much higher than that of SQL queries. Comparing this with Redis's sorted set means that you can grab the highest-rated items in the list in milliseconds, and it's very easy to implement.

/ / add the value ZADD sortedSet 1 "one" to the sorted set / / get all values from the sorted set ZRANGE sortedSet 0-1 WITHSCORES / get all values and weights from the sorted set

3. Session Session storage

The most common use of Redis that I have seen is session storage. Unlike other session stores, such as Memcache, Redis can retain data so that all data still exists when the cache is stopped and restarted. Even if it doesn't require strict and continuous tasks, this feature can still save your users a lot of trouble. No one would like to see their conversations randomly deleted for no reason.

/ / set the sessionSET randomHash "{userId}" EX 60Universe that expires in one minute / get the user IDGET randomHash

4. Queue

One of the less common but useful things you can do with Redis is queuing. Whether it's email queues or data used by other applications, you can create an efficient queue in Redis. This feature can be easily and naturally used by any developer who is familiar with stacks and push and pop projects.

/ / add message HSET messages ZADD due / / receive message ZRANGEBYSCORE due-inf LIMIT 0 1 HGET messages / / delete message ZREM due HDEL messages

5 、 pub/sub

The final use of Redis in the real world is the pub / sub that I will propose in this article. This is one of the most powerful features built into Redis; the results are likely to be unlimited. You can create a real-time chat system, trigger notifications for friend requests on social networks, and so on. This feature is one of the most underrated features provided by Redis, but it is very powerful and easy to use.

/ / push message PUBLISH channel message// to the channel to get message SUBSCRIBE channel from the channel

Conclusion:

I hope you like the use of these Redis in the real world. Although this article only scratches the surface of what Redis can do for you, I hope you get inspiration on how to make the most of Redis.

The above is a brief introduction of the use of redis and commonly used data types, of course, the detailed use of the above differences have to be used by everyone to understand. If you want to know more, welcome to follow the industry information channel!

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