Redis-01.初探

官网 http://redis.io

中文网 http://redis.cn

命令参考 http://redisdoc.cn

Redis（Remote Dictionary Server）是一个开源的key-value内存存储的NoSQL数据库，具有非常强悍的读写性能，现阶段正越来越多地被用于互联网高并发场景。

1 安装

Linux(CentOS 7.2)下yum方式安装

yum install redis

2 启动

2.1 交互模式启动

[root@VM_0_171_centos ~]# redis-server
23173:C 26 Mar 16:13:02.365 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
                _._
           _.-``__ ''-._
      _.-``    `.  `_.  ''-._           Redis 3.2.3 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 23173
  `-._    `-._  `-./  _.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |           http://redis.io
  `-._    `-._`-.__.-'_.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |
  `-._    `-._`-.__.-'_.-'    _.-'
      `-._    `-.__.-'    _.-'
          `-._        _.-'
              `-.__.-'

23173:M 26 Mar 16:13:02.366 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
23173:M 26 Mar 16:13:02.366 # Server started, Redis version 3.2.3
23173:M 26 Mar 16:13:02.366 # 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.
23173:M 26 Mar 16:13:02.366 # 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.
23173:M 26 Mar 16:13:02.366 * DB loaded from disk: 0.000 seconds
23173:M 26 Mar 16:13:02.366 * The server is now ready to accept connections on port 6379

2.2 后台启动

step 1：需要修改配置文件/etc/redis.conf

# By default Redis does not run as a daemon. Use 'yes' if you need it.
daemonize yes

step 2：使用配置文件启动

[root@VM_0_171_centos ~]# redis-server /etc/redis.conf
[root@VM_0_171_centos ~]#

3 客户端连接

[root@VM_0_171_centos ~]# redis-cli
127.0.0.1:6379> ping
PONG
127.0.0.1:6379>

4 停止服务

[root@VM_0_171_centos ~]# redis-shutdown
[root@VM_0_171_centos ~]#

5 其它程序

redis通过yum方式安装后，所有程序均位于/usr/bin目录

[root@VM_0_171_centos ~]# ls -l /usr/bin | grep redis
-rwxr-xr-x  1 root root      86832 8月   5 2016 redis-benchmark
-rwxr-xr-x  1 root root      15408 8月   5 2016 redis-check-aof
-rwxr-xr-x  1 root root     975248 8月   5 2016 redis-check-rdb
-rwxr-xr-x  1 root root     173344 8月   5 2016 redis-cli
lrwxrwxrwx  1 root root         12 3月  25 23:41 redis-sentinel -> redis-server
-rwxr-xr-x  1 root root     975248 8月   5 2016 redis-server
-rwxr-xr-x  1 root root        918 8月   5 2016 redis-shutdown
[root@VM_0_171_centos ~]#

其中redis-benchmark可以用来测试redis的性能，官网给出的信息是redis的读速度：110000次/s，写速度：81000次/s

[root@VM_0_171_centos ~]# redis-benchmark
====== PING_INLINE ======
  100000 requests completed in 0.69 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
145137.88 requests per second

====== PING_BULK ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
153846.16 requests per second

====== SET ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

99.97% <= 1 milliseconds
100.00% <= 1 milliseconds
153609.83 requests per second

====== GET ======
  100000 requests completed in 0.64 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
156250.00 requests per second

====== INCR ======
  100000 requests completed in 0.64 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
156006.25 requests per second

====== LPUSH ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
153846.16 requests per second

====== RPUSH ======
  100000 requests completed in 0.64 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
156985.86 requests per second

====== LPOP ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
153374.23 requests per second

====== RPOP ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
153374.23 requests per second

====== SADD ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
152671.77 requests per second

====== SPOP ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
154083.20 requests per second

====== LPUSH (needed to benchmark LRANGE) ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
153846.16 requests per second

====== LRANGE_100 (first 100 elements) ======
  100000 requests completed in 0.64 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

99.97% <= 1 milliseconds
100.00% <= 1 milliseconds
155279.50 requests per second

====== LRANGE_300 (first 300 elements) ======
  100000 requests completed in 0.64 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

99.99% <= 1 milliseconds
100.00% <= 1 milliseconds
155763.23 requests per second

====== LRANGE_500 (first 450 elements) ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
154320.98 requests per second

====== LRANGE_600 (first 600 elements) ======
  100000 requests completed in 0.65 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
153374.23 requests per second

====== MSET (10 keys) ======
  100000 requests completed in 0.63 seconds
  50 parallel clients
  3 bytes payload
  keep alive: 1

100.00% <= 0 milliseconds
159744.41 requests per second

[root@VM_0_171_centos ~]#

6 配置文件

通过yum方式安装后，redis的配置文件的位置为：/etc/redis.conf，包括前面提到的后台启动也是需要通过修改配置文件实现，配置项比较多，需要对redis有进一步了解

6.1 设置密码

如果要限制连接redis必须使用密码，需要配置requirepass选项：requriepass

################################## SECURITY ###################################

# Require clients to issue AUTH <PASSWORD> before processing any other
# commands.  This might be useful in environments in which you do not trust
# others with access to the host running redis-server.
#
# This should stay commented out for backward compatibility and because most
# people do not need auth (e.g. they run their own servers).
#
# Warning: since Redis is pretty fast an outside user can try up to
# 150k passwords per second against a good box. This means that you should
# use a very strong password otherwise it will be very easy to break.
#
requirepass 123456

设置密码后需要重启服务，再连接redis-cli时会提示需要验证授权，通过auth 命令验证

[root@VM_0_171_centos ~]# vim /etc/redis.conf
[root@VM_0_171_centos ~]# redis-server /etc/redis.conf
[root@VM_0_171_centos ~]# redis-cli
127.0.0.1:6379> ping
(error) NOAUTH Authentication required.
127.0.0.1:6379> auth 123456
OK
127.0.0.1:6379> ping
PONG
127.0.0.1:6379>

7 帮助

客户端连接redis后，可以通过help获取帮助，帮助信息里面给出了3种不同方式获取帮助，具体用法其它章节会进一步描述

127.0.0.1:6379> help
redis-cli 3.2.3
To get help about Redis commands type:
      "help @<group>" to get a list of commands in <group>
      "help <command>" for help on <command>
      "help <tab>" to get a list of possible help topics
      "quit" to exit

To set redis-cli perferences:
      ":set hints" enable online hints
      ":set nohints" disable online hints
Set your preferences in ~/.redisclirc