Redis series-1 [brief introduction]-What is it? What is it used? What are its advantages and disadvantages?

1.0 prerequisites

Objective: To have a conceptual understanding of what a memory-type database is .?

Read the following five blog posts about the redis series. This ID will be added one after another.

This ID redis Series

1. 0: first, this is your official redis Website:

Http://www.redis.cn/

1.1 you need to download, install, and configure redis successfully. For more information about the process, see another blog post on this ID:

Redis series-2 [installation and configuration]

1.2 If you need to understand the design and implementation of redis, please refer to this ID blog:

Redis series-3 [Design and Implementation of redis]

1.3 if you need to know the redis client, refer to other blog posts of this ID:

Redis series-4 [detailed analysis of redis client-jredis]

1.4 If You Need To Know How redis is integrated with storm, refer to the blog post of this ID:

Redis series-5 [storm-redis-pubsub]-storm Interface Series

? 1.5 If You Need To Know or encounter problems during use, please refer to another blog post of this ID

? ? Redis series-6 [difficult and problem diagnosis]-Qa time.

If there are any mistakes in the above blog posts or you have any questions, opinions, and suggestions about this ID blog, please give me feedback in time. Thank you for reading this article.

What is redis?

Generally, there are several types of databases, including SQL/nsql, relational databases, and key-value databases, redis is also a key-value database in nature, but it keeps the key-value database simple and fast, while absorbing the advantages of some relational databases. So that it is located between the relational database and the key-value data base. Redis not only saves strings data, but also stores lists (ordered) and sets (unordered) data. It also supports advanced functions such as sorting, this ensures the atomicity of operations when implementing functions such as incr and setnx. In addition, it also supports master-slave replication and other functions.

For more detailed descriptions, see:

Http://code.google.com/p/redis/wiki/index

Redis also provides a project code named retwis.

2 What is redis used?

Generally, redis also exists in the form of message queues as an embedded list to meet real-time high concurrency requirements. In the process of processing data of an e-commerce type, queues related to commodities, hot sales, and recommended sorting are usually stored in redis, during which storm is also expanded to read and update the redis list.

For a detailed example, refer to another blog post of this ID: Storm [topn] sorting. The storm-redis-pubsub interface is used during this period.

3 advantages of redis

• High Performance-redis supports read/write frequencies of over 100 K + per second.

• Rich data types-redis supports binary case strings, lists, hashes, sets, and Ordered Sets data type operations.

• All the operations of atomic redis are atomic, and redis also supports atomic execution after the sum of several operations.

• Rich features-redis also supports features such as Publish/subscribe, notification, and key expiration.

4. disadvantages of redis

Because the database capacity is limited by physical memory and cannot be used for high-performance read/write of massive data, redis is suitable for scenarios mainly limited to high-performance operations and operations with small data volumes.

Conclusion: due to specific scenarios, redis focuses on specific fields, and the speed is quite fast. Currently, no alternative products have been found.

 

Redis series-1 [brief introduction]-What is it? What is it used? What are its advantages and disadvantages?