[redis] redis installation

1 redis Introduction

redis It's a key-value The storage system . and Memcached similar , It supports storage value There are more types , Include string( character string )、list( Linked list )、set( aggregate )、zset(sorted set -- Ordered set ) and hash（ Hash type ）. these data type All support push/pop、add/remove And take intersection, union and difference sets and more abundant operations , And these operations are atomic . On this basis ,redis Support various sorts of sorting . And memcached equally , To ensure efficiency , The data is cached in memory . The difference is redis Periodically, updated data is written to disk or changes are written to an appended log file , And on this basis to achieve master-slave( Master-slave ) Sync .

Redis Is a high-performance key-value database . redis Appearance , A lot of compensation memcached This kind of key/value Insufficient storage , In some cases, it can play a very good complementary role to the relational database . It provides Java,C/C++,C#,PHP,JavaScript,Perl,Object-C,Python,Ruby,Erlang Such as the client , Easy to use . 

Redis Support master-slave synchronization . Data can be synchronized from the master server to any number of slaves , A slave server can be the master server associated with other slaves . This makes Redis Single-layer tree replication can be performed . The disk can write to the data intentionally or unintentionally . Because it's fully realized Release / subscribe Mechanism , Enables trees to be synchronized anywhere from the database , Subscribe to a channel and receive a complete record of message publication from the master server . Synchronization helps with scalability and data redundancy for read operations .

Reprint ：Redis_ Baidu Encyclopedia

1.1 redis What is it?

Redis:REmote DIctionary Server( Remote dictionary server ) It's completely open source and free , use C language-written , comply with BSD agreement , Is a high-performance (key/value) Distributed memory database , Run based on memory , And support persistent NoSQL database , It's the hottest NoSql One of the databases , Also known as data structure server .

Redis And others key - value Cache products have the following three characteristics ：

• Redis Support data persistence , Data in memory can be kept on disk , When you restart, you can load it again for use ;

• Redis It's not just about supporting simple key-value Data of type , It also provides list,set,zset,hash Such as data structure storage ;

• Redis Support data backup , namely master-slave Mode data backup .

1.2  What can I do?

• Memory storage and persistence ：redis Support asynchronous write data in memory to hard disk , At the same time, it does not affect the continued service

• Take the latest N Data operations , Such as ： You can put the latest 10 Of comments ID Put it in Redis Of List In the assembly

• The simulation is similar to HttpSession This function needs to set expiration time

• Release 、 Subscribe to the messaging system

• Timer 、 Counter

1.3  Where to download

• Redis Official website ：Redis

• Redis Chinese net ：CRUG Website

1.4  How do you play?

• data type 、 Basic operation and configuration

• Persistence and replication ,RDB/AOF

• Control of transactions

• Copy （ Master-slave relationship ）

2 redis Installation

linus：centos7

redis edition ：redis-4.0.11

After downloading the compressed package on the official website , Drag into virtual machine , decompression

tar -zxvf redis-4.0.11.tar.gz

  notes ： The version I first installed is 6.0.9, But the later installation was unsuccessful , So I changed the version , It uses 4.0.11. The installation process is the same , The screenshot uses 6.0.9

Enter the unzipped installation package

make

gcc The order was not found ！！！【 This machine is missing gcc Environment 】

gcc yes linux Compiler under , yes C Compiler for , install gcc

yum install gcc-c++

Again make

Need to put the first make Clean up your files . make distclean Again after make

make install

/usr: Many of the user's applications and files are in this directory , similar windows Under the program files file

Get into opt/redis4.0.11 Next , Copy redis.conf Go to the new directory usr/etc/ Next

To configure redis-conf. Be careful , stay root Use by user vim

vim redis-conf

Modify the daemon to yes

Check with the command redis Has the process of ：

ps -ef|grep redis

start-up redis

redis-server /usr/etc/redis.conf        ##  Start the configured , Didn't touch the original 

redis-cli -p 6379, It means that

 redis yes k-v Key value pair

The process has started in the background

Turn off the redis

Look at the process again , No, redis process

3 redis Miscellaneous basics after startup

3.1  test set and get

cd /usr/local/bin

3.3 

3.2  Single process

• Single process model to handle client requests . Response to events such as reading and writing Is based on epoll Function to do this .Redis The actual processing speed of depends on the execution efficiency of the main process

• epoll yes Linux The kernel has made improvements to handle large quantities of file descriptors epoll, yes Linux Lower multiplexing IO Interface select/poll Enhanced version of , It can significantly improve the system when the program is only active in a large number of concurrent connections CPU utilization .

3.3  library

Default 16 A database , Similar array the following table starts from zero , The initial default is to use library zero , It can be configured in the configuration file .

3.4  A simple command

select Command switch database

dbsize Check the... Of the current database key The number of

see key Number

• flushdb： Empty the current library

• flushall; Kill all the warehouses

• Unified password management ,16 Every library is the same password , Or both OK Or none of them can connect

• Redis Indexes start from scratch

• Why is the default port 6379 Nine key middle ：6-m 3-e 7-r 0-z merz

Study ： Silicon Valley super classic Redis course ,redis actual combat , Brother Yang version from introduction to mastery _ Bili, Bili _bilibili