用shell脚本监控MySQL主从同步

企业面试题1：（生产实战案例）：监控MySQL主从同步是否异常，如果异常，则发送短信或者邮件给管理员。提示：如果没主从同步环境,可以用下面文本放到文件里读取来模拟：
阶段1：开发一个守护进程脚本每30秒实现检测一次。
阶段2：如果同步出现如下错误号（1158,1159,1008,1007,1062），则跳过错误。
阶段3：请使用数组技术实现上述脚本（获取主从判断及错误号部分）

 [root@mysql01 shell]# mysql -uroot -poldboy123 -S /data//mysql.sock -e "show slave status\G"
 Warning: Using a password on the command line interface can be insecure.
 *************************** . row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 172.16.1.52
                   Master_User: rep
                   Master_Port:
                 Connect_Retry:
               Master_Log_File: mysql-bin.
           Read_Master_Log_Pos:
                Relay_Log_File: relay-bin.
                 Relay_Log_Pos:
         Relay_Master_Log_File: mysql-bin.
              Slave_IO_Running: Yes
             Slave_SQL_Running: Yes
               Replicate_Do_DB:
           Replicate_Ignore_DB:
            Replicate_Do_Table:
        Replicate_Ignore_Table:
       Replicate_Wild_Do_Table:
   Replicate_Wild_Ignore_Table:
                    Last_Errno:
                    Last_Error:
                  Skip_Counter:
           Exec_Master_Log_Pos:
               Relay_Log_Space:
               Until_Condition: None
                Until_Log_File:
                 Until_Log_Pos:
            Master_SSL_Allowed: No
            Master_SSL_CA_File:
            Master_SSL_CA_Path:
               Master_SSL_Cert:
             Master_SSL_Cipher:
                Master_SSL_Key:
         Seconds_Behind_Master:
 Master_SSL_Verify_Server_Cert: No
                 Last_IO_Errno:
                 Last_IO_Error:
                Last_SQL_Errno:
                Last_SQL_Error:
   Replicate_Ignore_Server_Ids:
              Master_Server_Id:
                   Master_UUID: 74e721f9-3c82-11e8-a818-000c29a97a9f
              Master_Info_File: /data//data/master.info
                     SQL_Delay:
           SQL_Remaining_Delay: NULL
       Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
            Master_Retry_Count:
                   Master_Bind:
       Last_IO_Error_Timestamp:
      Last_SQL_Error_Timestamp:
                Master_SSL_Crl:
            Master_SSL_Crlpath:
            Retrieved_Gtid_Set:
             Executed_Gtid_Set:
                 Auto_Position: 

1、编写shell脚本：

系统：centos6.7

Mysql:多实例主从同步

#!/bin/bash

#-------------CopyRight-------------
#   Name:MySQL Check master and slave
#   Version Number:1.00
#   Type:sh
#   Language:bash shell
#   Date:--
#   Author:xubing
#   QQ:
#   Email:eeexu123@.com
#   Blog:https://www.cnblogs.com/eeexu123/

Port=3307                                         //MySQL端口
User="root"                                       //MySQL用户
Password="oldboy123"                              //MySQL用户密码
Mysql_sock="/data/${Port}/mysql.sock"             //mysql.sock随着每次MySQL启动而生成
Mysql_cmd="/application/mysql/bin/mysql -u${User} -p${Password} -S $Mysql_sock -e"  //MySQL非交互命令
Error_file="/tmp/mysql_check_error.log"   //错误输入文件

#source functions libary
. /etc/init.d/functions

#check mysql server    //检查MySQL是否启动
[ -e $Mysql_sock ]||{
  echo "The Mysql server no start"
  exit
}

#function ingore errors    //忽略错误函数
skip_errors(){
  array=(    )
  flag=
  for num in ${array[*]}
  do
    if [ "$1" = "$num" ];then    //如果有对应的错误号，MySQL就跳过此错误号
       ${Mysql_cmd} "stop slave;set global sql_slave_skip_counter = 1;start slave;"
       echo "Last_IO_Errno:$1">>$Error_file
    else
       echo "Last_IO_Errno:$1">>$Error_file
       ((flag++))   //如果此错误号不在array数组中，将此错误号写入错误文件中，并循环五次
    fi
  done

  if [ $flag = ${#array[@]} ];then   //发送邮件
     echo "**********`date +%F_%T`************">>$Error_file
     uniq $Error_file|mail -s "Mysql Slave error" eeexu123@.com
  fi
}

#check mysql slave  //检查从库是否正常
check_mysql(){
  array1=(`${Mysql_cmd} "show slave status\G"|egrep "Slave_IO_Running|Slave_SQL_Running|Last_SQL_Errno|Seconds_Behind_Master"|awk '{print $NF}'`)
  if [ "${array1[0]}" = "Yes" -a "${array1[1]}" == "Yes" -a "${array1[2]}" =  ];then
     action "Mysql Slave" /bin/true
  else
     action "Mysql Slave" /bin/false
     if [ "${array1[0]}" != "Yes" ];then   //将上述错误的列写入到错误文件中
        ${Mysql_cmd} "show slave status\G"|grep "Slave_IO_Running">>$Error_file
     elif [ "${array1[1]}" != "Yes" ];then
        ${Mysql_cmd} "show slave status\G"|grep "Slave_SQL_Running"|grep -v "Slave_SQL_Running_State">>$Error_file
     else [ "${array1[2]}" !=  ]
        ${Mysql_cmd} "show slave status\G"|grep "Seconds_Behind_Master">>$Error_file
     fi
     skip_errors ${array1[]}  //发送邮件
  fi
}

main(){
  while true
  do
    check_mysql
    sleep
  done
}
main

2、检测（执行脚本）

a:检测忽略号

先在从库3307中创建库

mysql>  create database taili123;
Query OK,  row affected (0.00 sec)

再在主库3306中创建库

mysql>  create database taili123;
Query OK,  row affected (0.00 sec)

再次查看从库状态如下：出现错误代码

 mysql> show slave status\G
 *************************** . row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 172.16.1.52
                   Master_User: rep
                   Master_Port:
                 Connect_Retry:
               Master_Log_File: mysql-bin.
           Read_Master_Log_Pos:
                Relay_Log_File: relay-bin.
                 Relay_Log_Pos:
         Relay_Master_Log_File: mysql-bin.
              Slave_IO_Running: Yes
             Slave_SQL_Running: No
               Replicate_Do_DB:
           Replicate_Ignore_DB:
            Replicate_Do_Table:
        Replicate_Ignore_Table:
       Replicate_Wild_Do_Table:
   Replicate_Wild_Ignore_Table:
                    Last_Errno:
                    Last_Error: Error 'Can't create database 'taili123'; database exists' on query. Default database: 'taili123'. Query: 'create database taili123'
                  Skip_Counter:
           Exec_Master_Log_Pos:
               Relay_Log_Space:
               Until_Condition: None
                Until_Log_File:
                 Until_Log_Pos:
            Master_SSL_Allowed: No
            Master_SSL_CA_File:
            Master_SSL_CA_Path:
               Master_SSL_Cert:
             Master_SSL_Cipher:
                Master_SSL_Key:
         Seconds_Behind_Master: NULL
 Master_SSL_Verify_Server_Cert: No
                 Last_IO_Errno:
                 Last_IO_Error:
                Last_SQL_Errno:
                Last_SQL_Error: Error 'Can't create database 'taili123'; database exists' on query. Default database: 'taili123'. Query: 'create database taili123'
   Replicate_Ignore_Server_Ids:
              Master_Server_Id:
                   Master_UUID: 74e721f9-3c82-11e8-a818-000c29a97a9f
              Master_Info_File: /data//data/master.info
                     SQL_Delay:
           SQL_Remaining_Delay: NULL
       Slave_SQL_Running_State:
            Master_Retry_Count:
                   Master_Bind:
       Last_IO_Error_Timestamp:
      Last_SQL_Error_Timestamp:  ::
                Master_SSL_Crl:
            Master_SSL_Crlpath:
            Retrieved_Gtid_Set:
             Executed_Gtid_Set:
                 Auto_Position: 

查看脚本执行状态：

 [root@mysql01 shell]# sh ckmysql_master_slave.sh
 Warning: Using a password on the command line interface can be insecure.
 Mysql Slave                                                [失败]
 Warning: Using a password on the command line interface can be insecure.
 Warning: Using a password on the command line interface can be insecure.
 Warning: Using a password on the command line interface can be insecure.
 Mysql Slave                                                [失败]
 Warning: Using a password on the command line interface can be insecure.
 Warning: Using a password on the command line interface can be insecure.
 Warning: Using a password on the command line interface can be insecure.
 Mysql Slave                                                [确定]

b:检测发送邮件

在从库中停止SQL线程

mysql> stop slave sql_thread;
Query OK,  rows affected (0.02 sec)

再次查看从库状态

 mysql> show slave status\G
 *************************** . row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 172.16.1.52
                   Master_User: rep
                   Master_Port:
                 Connect_Retry:
               Master_Log_File: mysql-bin.
           Read_Master_Log_Pos:
                Relay_Log_File: relay-bin.
                 Relay_Log_Pos:
         Relay_Master_Log_File: mysql-bin.
              Slave_IO_Running: Yes
             Slave_SQL_Running: No
               Replicate_Do_DB:
           Replicate_Ignore_DB:
            Replicate_Do_Table:
        Replicate_Ignore_Table:
       Replicate_Wild_Do_Table:
   Replicate_Wild_Ignore_Table:
                    Last_Errno:
                    Last_Error:
                  Skip_Counter:
           Exec_Master_Log_Pos:
               Relay_Log_Space:
               Until_Condition: None
                Until_Log_File:
                 Until_Log_Pos:
            Master_SSL_Allowed: No
            Master_SSL_CA_File:
            Master_SSL_CA_Path:
               Master_SSL_Cert:
             Master_SSL_Cipher:
                Master_SSL_Key:
         Seconds_Behind_Master: NULL
 Master_SSL_Verify_Server_Cert: No
                 Last_IO_Errno:
                 Last_IO_Error:
                Last_SQL_Errno:
                Last_SQL_Error:
   Replicate_Ignore_Server_Ids:
              Master_Server_Id:
                   Master_UUID: 74e721f9-3c82-11e8-a818-000c29a97a9f
              Master_Info_File: /data//data/master.info
                     SQL_Delay:
           SQL_Remaining_Delay: NULL
       Slave_SQL_Running_State:
            Master_Retry_Count:
                   Master_Bind:
       Last_IO_Error_Timestamp:
      Last_SQL_Error_Timestamp:
                Master_SSL_Crl:
            Master_SSL_Crlpath:
            Retrieved_Gtid_Set:
             Executed_Gtid_Set:
                 Auto_Position: 

查看邮件收发，接收如下状态：