redis初次使用报错杂谈

第一次在Java中用jedis时的错误总结
1.redis.clients.jedis.exceptions.JedisConnectionException: Failed connecting to host 192.168.209.128:6379
用root权限启动的redis，但是在wind中的eclipse连接Linux的redis是用的我的自建用户，用redis-cli shutdown 停止redis并切换成自建用户并启动redis。

2.报连接超时。经分析是Linux防护墙拦截了。
a.关闭防火墙
查看防护墙状态：sudo ufw status
开启/关闭防火墙 (默认设置是’disable’)：sudo ufw enable|disable
b.设置防火墙允许6379接口
设置端口许可： sudo iptables -I INPUT -p tcp --dport 6379 -j ACCEPT
保存防火墙设置： iptables-save
3.redis.clients.jedis.exceptions.JedisDataException: 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.
Redis默认状态下是一守护状态下安装运行的，所以如果不是本地连接，就会报这个错误。redis的保护模式已经激活。没有绑定特定的连接ip地址，没有授权密码，
在这种情况下，连接只能是本地连接。
而想要从外部连接，则可以采取以下几种方式：
1）：redis服务器运行时，在本地连接，并且运行命令：CONFIG SET protected-mode no.但是如果你要这样做，
你要确保Redis不要公开在互联网上，使用命令CONFIG REWRITE来使文件来永久的改变
2）：第二种方式，你可以编辑Redis的配置文件，将protected mode选项的值改成no，并重新启动redis服务
3）：如果你启动Redis只是为了测试使用，你可以重启Redis服务，加上–protected-mode no参数
4）：设置绑定特定的ip地址或者给一个身份密码