Redis笔记-单机版安装

1、几个相关概念

概念	现象描述	规避措施
穿透	通过访问一个缓存中不存在的key，导致程序一定要在数据库中执行查询	将访问结果进行处理，如果返回是null，也存储在缓存中，可以将过期时间设置较短
雪崩	某一个时间段内，大量缓存key同时失效，导致访问直接查询数据库	讲不同的缓存数据进行分级分类，并进行不通的过期时间设置，例如可以通过定值+随机的方式生成过期时间，防止集中失效的的情况
击穿	缓存中某个key被访问的频率极高，在缓存失效的瞬间，访问直接访问数据库，比如商城的爆款等	可以将对应的缓存过期时间设置较大甚至是永不过期来规避

2、Linux安装(以CentOS 7.X为例)

step1、到官网下载对应的tar安装包http://download.redis.io/releases截止目前，最新版本已经发布到5.X

　　下载：wget http://download.redis.io/releases/redis-5.0.4.tar.gz

　　解压：tar zxvf redis-5.0.4.tar.gz

step2、编译

　　cd redis-5.0.4 然后执行make

　　编译完进入src目录，可以看到生成对应的文件如下：

[root@VM_0_14_centos redis-5.0.4]# ll
total 264
-rw-rw-r--  1 root root 99445 Mar 19 00:21 00-RELEASENOTES
-rw-rw-r--  1 root root    53 Mar 19 00:21 BUGS
-rw-rw-r--  1 root root  1894 Mar 19 00:21 CONTRIBUTING
-rw-rw-r--  1 root root  1487 Mar 19 00:21 COPYING
drwxrwxr-x  6 root root  4096 Mar 20 16:00 deps
-rw-rw-r--  1 root root    11 Mar 19 00:21 INSTALL
-rw-rw-r--  1 root root   151 Mar 19 00:21 Makefile
-rw-rw-r--  1 root root  4223 Mar 19 00:21 MANIFESTO
-rw-rw-r--  1 root root 20555 Mar 19 00:21 README.md
-rw-rw-r--  1 root root 62155 Mar 19 00:21 redis.conf
-rwxrwxr-x  1 root root   275 Mar 19 00:21 runtest
-rwxrwxr-x  1 root root   280 Mar 19 00:21 runtest-cluster
-rwxrwxr-x  1 root root   281 Mar 19 00:21 runtest-sentinel
-rw-rw-r--  1 root root  9710 Mar 19 00:21 sentinel.conf
drwxrwxr-x  3 root root  4096 Mar 20 16:01 src
drwxrwxr-x 10 root root  4096 Mar 19 00:21 tests
drwxrwxr-x  8 root root  4096 Mar 19 00:21 utils
[root@VM_0_14_centos redis-5.0.4]# 
[root@VM_0_14_centos redis-5.0.4]# 
[root@VM_0_14_centos redis-5.0.4]# 
[root@VM_0_14_centos redis-5.0.4]# 
[root@VM_0_14_centos redis-5.0.4]# 
[root@VM_0_14_centos redis-5.0.4]# cd src
[root@VM_0_14_centos src]# ls -lrt redis-*
-rwxr-xr-x 1 root root 8100759 Mar 20 16:01 redis-server
-rwxr-xr-x 1 root root 8100759 Mar 20 16:01 redis-sentinel
-rwxr-xr-x 1 root root 4805624 Mar 20 16:01 redis-cli
-rwxr-xr-x 1 root root 4365280 Mar 20 16:01 redis-benchmark
-rwxr-xr-x 1 root root 8100759 Mar 20 16:01 redis-check-rdb
-rwxr-xr-x 1 root root 8100759 Mar 20 16:01 redis-check-aof

step3、新建redis目录/usr/redis，并将文件copy进去（目前以单节点测试，先可以不用copy其他文件）

1 [root@VM_0_14_centos /]# mkdir /usr/redis
2 [root@VM_0_14_centos /]# cp /data01/redis-5.0.4/redis.conf /usr/redis/
3 [root@VM_0_14_centos /]# cp /data01/redis-5.0.4/src/redis-server /usr/redis/
4 [root@VM_0_14_centos /]# cp /data01/redis-5.0.4/src/redis-cli /usr/redis/
5 [root@VM_0_14_centos /]#

step4、启动测试 ./redis-server redis.conf

 1 [root@VM_0_14_centos redis]# 
 2 [root@VM_0_14_centos redis]# ./redis-server redis.conf 
 3 6440:C 20 Mar 2019 16:16:13.047 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
 4 6440:C 20 Mar 2019 16:16:13.047 # Redis version=5.0.4, bits=64, commit=00000000, modified=0, pid=6440, just started
 5 6440:C 20 Mar 2019 16:16:13.047 # Configuration loaded
 6                 _._                                                  
 7            _.-``__ ''-._                                             
 8       _.-``    `.  `_.  ''-._           Redis 5.0.4 (00000000/0) 64 bit
 9   .-`` .-```.  ```\/    _.,_ ''-._                                   
10  (    '      ,       .-`  | `,    )     Running in standalone mode
11  |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
12  |    `-._   `._    /     _.-'    |     PID: 6440
13   `-._    `-._  `-./  _.-'    _.-'                                   
14  |`-._`-._    `-.__.-'    _.-'_.-'|                                  
15  |    `-._`-._        _.-'_.-'    |           http://redis.io        
16   `-._    `-._`-.__.-'_.-'    _.-'                                   
17  |`-._`-._    `-.__.-'    _.-'_.-'|                                  
18  |    `-._`-._        _.-'_.-'    |                                  
19   `-._    `-._`-.__.-'_.-'    _.-'                                   
20       `-._    `-.__.-'    _.-'                                       
21           `-._        _.-'                                           
22               `-.__.-'                                               
23 
24 6440:M 20 Mar 2019 16:16:13.048 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
25 6440:M 20 Mar 2019 16:16:13.048 # Server initialized
26 6440:M 20 Mar 2019 16:16:13.048 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
27 6440:M 20 Mar 2019 16:16:13.048 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
28 6440:M 20 Mar 2019 16:16:13.048 * Ready to accept connections

开启客户端，并测试：

1 [root@VM_0_14_centos redis]# 
2 [root@VM_0_14_centos redis]# ./redis-cli 
3 127.0.0.1:6379> 
4 127.0.0.1:6379> 
5 127.0.0.1:6379> set name hello
6 OK
7 127.0.0.1:6379> get name
8 "hello"
9 127.0.0.1:6379>