Redis知识点
1、关于配置文件
redis启动如果不显式地指定配置文件，则默认不使用任何配置文件，而是使用它自己的默认配置。所以，如果修改了配置文件的内容，但若启动时没有显式地指定它，则对它的修改不会有任何效果。
如果redis_6379里配置文件是/etc/redis/6379.conf，则使用redis-server /etc/redis/6379.conf启动，与使用/etc/init.d/redis_6379start启动是启动的同一个实例。
vim /etc/init.d/redis_6379
#!/bin/sh#Configurations injected by install_server below.... EXEC=/usr/local/bin/redis-serverCLIEXEC=/usr/local/bin/redis-cliPIDFILE=/var/run/redis_6379.pidCONF="/etc/redis/6379.conf"REDISPORT="6379"
2、Redis复制
（1）在同一台主机的不同实例之间实现复制：只需在slave实例的配置文件中，添加:
slaveof master_ip master_port
就可以了；
（2）在不同主机之间实现复制：除了实现（1）中的配置之外，还需要：
A.在master的配置文件中注释掉监听地址 bind一行
B.将protected-mode的值由yes改为no（仅限没有设置bind并且没有设置密码的时候）
设置密码：
在配置文件中加入
requirepass redis
以上"redis"即为密码。保存后重启master的服务。
[root@host103 ~]# /etc/init.d/redis_6379 restartStopping ...Redis stoppedStarting Redis server...[root@host103 ~]# redis-cli -p 6379 infoNOAUTH Authentication required.[root@host103 ~]# redis-cli -p 6379127.0.0.1:6379> keys * (error) NOAUTH Authentication required.127.0.0.1:6379> auth redisOK127.0.0.1:6379> keys *1) "c"2) "d"3) "a"4) "b"5) "e"
在master设置密码之后，slave是无法与其进行同步的，此时要修改slave的配置文件：
slaveof 127.0.0.1 6379# If the master is password protected (using the "requirepass" configuration# directive below) it is possible to tell the slave to authenticate before# starting the replication synchronization process, otherwise the master will# refuse the slave request.## masterauthmasterauth redis
保存并重启slave服务。
遇到的一个问题：
在虚拟机不同主机（192.168.1.111和192.168.1.112）之间配置redis复制，slave端已经加入"slaveof 192.168.1.111 6378"，并且在master注释掉bind,但无法实现复制，在slave上显示：
redis-cli -p 6379 info
查看slave端的日志：
tail -n200 /var/log/redis_6379.log
在112上运行如下命令：
[root@host112 log]# telnet 192.168.1.111 6379
有如下结果：
[root@host112 log]# telnet 192.168.1.111 6379
Trying 192.168.1.111...
Connected to 192.168.1.111.
Escape character is '^]'.
-DENIED Redis is running in protected mode because protected mode is enabled, no bind address was specified, no authentication password is requested to clients. In this mode connections are only accepted from the loopback interface. If you want to connect from external computers to Redis you may adopt one of the following solutions: 1) Just disable protected mode sending the command 'CONFIG SET protected-mode no' from the loopback interface by connecting to Redis from the same host the server is running, however MAKE SURE Redis is not publicly accessible from internet if you do so. Use CONFIG REWRITE to make this change permanent. 2) Alternatively you can just disable the protected mode by editing the Redis configuration file, and setting the protected mode option to 'no', and then restarting the server. 3) If you started the server manually just for testing, restart it with the '--protected-mode no' option. 4) Setup a bind address or an authentication password. NOTE: You only need to do one of the above things in order for the server to start accepting connections from the outside.
Connection closed by foreign host.
参考http://arui.me/index.php/archives/151/
将master的这一项protected-mode由yes改为no，就可以正常实现复制了。该参数是3.2版本之后加入的新特性。
（未完待续）
