MySQL远程连接失败(错误码:2003)

MySQL远程连接失败(错误码:2003)

更新于2018年3月12日

一 环境信息

  • 服务器系统:Oracle Linux 7.3
  • 服务器MySQL版本:MySQL 5.7.20
  • 本地系统:win10
  • 本地客户端:Navicat for MySQL 10.1.7
  • 本地开发环境:python(3.6.3),PyMySQL(0.8.0)
  • 假设:登录用户名为admin,密码为adminpwd ,MySQL连接端口3306

二 问题描述

  • 本地客户端及代码连接均失败: 2003, "Can't connect to MySQL server on '192.168.1.166' (10061)"

  • python连接MySQL代码

import pymysql
conn= pymysql.connect(
         host='192.168.1.166',
         port = 3306,
         user='admin',
         passwd='adminpwd',
         db ='test',
         charset='utf8'
         )
# 使用cursor方法获取操作游标
cur = conn.cursor()
# 使用execute 方法执行sql语句
cur.execute("select version()")
# 使用fetchone()方法获取一条数据库
data = cur.fetchone()
print("datebase version : %s"%data)
# 关闭数据库连接
conn.close()
  • python连接MySQL报错
Traceback (most recent call last):    
File "D:/JetBrains/test/study_test/mysql_test1.py", line 15, in <module>
 charset='utf8'
File "D:\JetBrains\pyEnv\python363\lib\site-packages\pymysql\__init__.py", line 90, in Connect
 return Connection(*args, **kwargs)
File "D:\JetBrains\pyEnv\python363\lib\site-packages\pymysql\connections.py", line 699, in __init__
 self.connect()
File "D:\JetBrains\pyEnv\python363\lib\site-packages\pymysql\connections.py", line 967, in connect
 raise exc
pymysql.err.OperationalError: (2003, "Can't connect to MySQL server on '192.168.1.166' (timed out)")         

三 官方文档描述

    "The error (2003) Can't connect to MySQL server on 'server' (10061) indicates that the network connection has been refused. You should check that there is a MySQL server running, that it has network connections enabled, and that the network port you specified is the one configured on the server."
    金山译文:错误(2003年)无法连接到“server”(10061)上的mysql服务器,表示网络连接已被拒绝。您应该检查是否有一个mysql服务器正在运行,它是否启用了网络连接,并且您指定的网络端口是在服务器上配置的。

四 解决过程

  • (1) Xshell远程登陆服务器,用“ps aux|grep mysql”命令查看,MySQL服务已启动:

  • (2) 用"vim my.cnf"命令查看my.cnf文件(在MySQL安装目录下,我的位置是/usr/local/mysql/my.cnf),修改其对应的值并重启MySQL。对应内容如下:

[mysqld]
bind-address = 0.0.0.0  # 表示允许任何主机登陆MySQL
port=3306               # 表示MySQL运行端口为3306
  • (3)用“mysql -u admin -p”命令,回车后输入密码“adminpsw”能正常登陆服务器MySQL
mysql> show global variables like 'port';  # 查看MySQL运行的实际端口
+---------------+-------
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.01 sec)
  mysql> use mysql;
  Reading table information for completion of table and column names
  You can turn off this feature to get a quicker startup with -A
  
  Database changed
  mysql> select host,user from user;
  +-----------+---------------+
  | host      | user          |
  +-----------+---------------+
  | %         | admin         |
  | %         | root          |
  | localhost | mysql.session |
  | localhost | mysql.sys     |
  +-----------+---------------+
  5 rows in set (0.00 sec)
  # 如果上述查询结果,admin用户对应的host不为%,则修改用户权限
  # 此处需注意的是,修改权限时要带上密码(IDENTIFIED BY 'adminpwd'),虽然不知道具体原理,但是没加密码之前客户端还是不能远程访问MySQL。   
  mysql> GRANT ALL PRIVILEGES ON *.* TO 'admin'@'%' IDENTIFIED BY 'adminpwd' WITH GRANT OPTION; 
  Query OK, 0 rows affected, 1 warning (0.00 sec)

  mysql> FLUSH PRIVILEGES;
  Query OK, 0 rows affected (0.00 sec)

  • (4) 至此,我的本地Navicat客户端已经能都正常访问服务器端,但是运行上述python连接MySQL代码还是报一样的错误。

  • (5)查网上资料说可能是防火墙屏蔽了3306端口,本地cmd"ping 192.168.1.166"能够Ping通,再用”telnet 192.168.1.166 3306“命令检查端口是否被屏蔽,结果为"正在连接192.168.1.166...无法打开到主机的连接。 在端口 3306: 连接失败",说明是防火墙的问题
    (如果Win10 telnet不是内部或外部命令,决解方法参考连接:https://jingyan.baidu.com/article/1e5468f9033a71484961b7d7.html)

  • (6) 起初我以为是指我本地防火墙的问题,于是把本地防火墙关了,结果问题并没有解决。

  • (7) 其实应该是远程服务器的防火墙问题。远程登陆服务器(我用root用户登录的),检查防火墙状态

systemctl start firewalld # 开启防火墙
systemctl stop firewalld  # 关闭防火墙
systemctl status firewalld  #检查防火墙状态
  • (8) 关闭远端服务器防火墙后,运行本地运行本地python连接MySQL代码,MySQL连接成功
[root@db sysconfig]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: active (running) since 三 2018-02-28 17:18:10 CST; 7s ago
     Docs: man:firewalld(1)
 Main PID: 5452 (firewalld)
   CGroup: /system.slice/firewalld.service
           └─5452 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid
[root@db sysconfig]# systemctl stop firewalld
[root@db sysconfig]# systemctl status firewalld
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled)
   Active: inactive (dead)
     Docs: man:firewalld(1)
  • (9)如果你觉得关闭防火墙不安全,可打开远端服务器的iptables(安装或升级命令“yum install iptables”)(我用root用户登录的),并用“vi /etc/sysconfig/iptables”检查3306端口是否打开,如没有,在文件中加入“-A INPUT -p tcp -m tcp --dport 3306 -j ACCEPT”(如下所示),保存文件并用“service iptables restart”命令重启iptables
# Generated by iptables-save v1.4.21 on Wed Feb 28 12:19:33 2018
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [34:3136]
-A INPUT -p tcp -m tcp --dport 3306 -j ACCEPT    ## 加上此行
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibite
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
# Completed on Wed Feb 28 12:19:33 2018
~                                                                                                  
~                                                                                                       
"/etc/sysconfig/iptables" 17L, 654C
  • (10)运行本地python连接MySQL代码,结果如下:
datebase version : 5.7.20-enterprise-commercial-advanced
posted @ 2018-02-28 10:57  大懒虫哇咔咔  阅读(98600)  评论(3编辑  收藏  举报