基于Docker的mysql keepalived 的集群环境构建
- 概述
- 切换原理和过程
- docker-compose配置Mysql主从高可用
- 切换脚本说明
- 演练过程
- 文件详情
* docker-compose
* keepalived.conf
* mycheck
* mymaster
* mybackup
* mystop
* my.cnf
* mysqlenv
概述
-
目的
为解决Mysql数据库单点问题,实现数据库的高可用。当Master数据库出现问题时,Slave切换为Master继续工作。当Master主机宕机时,由于无法通过scp拷贝位置文件,会导致无法恢复同步复制,需手动恢复同步复制。 -
环境说明
| 序号 | 服务器IP | 用途 | 备注 |
| 1 | 172.19.0.2 | 主机A | Master |
| 2 | 172.19.0.3 | 主机B | Slave |
| 3 | 172.19.0.110 | VIP |
切换原理和过程
Keepalived可实现将虚拟IP地址在实体物理机上来回漂移。Keepalived在转换状态时会依照状态来呼叫配置文件中内置的定义。
当进入Master状态时会呼叫notify_master定义的脚本
当进入Backup状态时会呼叫notify_backup定义的脚本
当keepalived程序终止时呼叫notify_stop定义的脚本
当发现异常情况时进入Fault状态呼叫notify_fault定义的脚本
切换的过程如下:
1)在Master主机上keepalived运行时执行mycheck.sh脚本不停的检查mysql的运行状态,当发现mysql停止后将keepalived进程杀掉。
2)此时Slave主机上会接管虚拟IP地址,并调用notify_master定义的脚本
3)当原Master主机上的mysql和keepalived进程恢复正常后,会调用notify_backup定义的脚本,此时数据库的主端还在Savle主机上。
4)回切,关闭Slave端的keepavlied进程,会调用notify_stop脚本,同时Master主机上会调用notify_master定义的脚本。此时数据库的主端在Master主机上
5)启动Slave端的keepavlied进程,会调用notify_backup脚本,此时完成数据同步。
docker-compose配置Mysql主从高可用
- 文件列表
├── docker-compose.yml
└── mysql
├── master
│ ├── config
│ │ ├── keepalived.conf
│ │ ├── my.cnf
│ │ └── mysqlenv
│ ├── data
│ └── init
├── slave
│ ├── config
│ │ ├── keepalived.conf
│ │ ├── my.cnf
│ │ └── mysqlenv
│ ├── data
│ └── init
├── scripts
│ ├── master
│ │ └── logs
│ ├── slave
│ │ └── logs
│ ├── mybackup.sh
│ ├── mycheck.sh
│ ├── mymaster.sh
│ ├── mystop.sh- docker-compose.yml文件说明(文件内容)
创建mysql-master和mysql-slave容器的配置文件
# 创建并启动容器
# docker-compose up -d
# 登陆Master
# docker exec -it mysql-master /bin/bash注意:docker宿主机需安装keepalived和ipvsadm,否则容器中的keepalived服务无法正常启动
# 在宿主机中执行以下指令安装keepalived和ipvsadm
# yum install -y keepalived ipvsadm
# ipvsadm --save > /etc/sysconfig/ipvsadm
# echo 1 > /proc/sys/net/ipv4/ip_forward
# systemctl enable ipvsadm
# systemctl start ipvsadm
# 开机启动需配置net.ipv4.ip_forward=1到/etc/sysctl.conf切换脚本说明
-
检查脚本mycheck(文件内容)
检查mysql运行状态,如果运行正常,退出。如果运行不正常调用pkill keepalived -
切换脚本mymaster(文件内容)
先判断同步复制是否执行完成,如果未执行完成等待1分钟后,停止同步(stop slave),并且记录切换后的日志和pos -
回切脚本mybackup(文件内容)
清空slave配置,重新获取远程日志文件及Pos,并开启同步 -
停止脚本mystop(文件内容)
设置参数保证数据不丢失,最后检查看是否还有写操作,最后1分钟退出
演练过程
- master端数据库宕机(中止mysqld数据库服务),发生:(1)master端keepalived被中止;(2)vip飘到slave端,并调用mymaster.sh脚本停止slave进程复制,相当于服务切换至slave端。
- 恢复master端数据库(启动mysqld数据库服务)和keepalived服务,发生:master端调用mybackup.sh脚本启动slave进程复制,相当于同步复制切换至master端。
- slave端数据库宕机。
- 恢复slave端数据库。
注意:12步骤切换,34步骤恢复
[root@localhost mysql]# docker-compose up -d
<-----启动容器
[root@localhost mysql]# docker exec -it mysql-master systemctl stop mysqld
[root@localhost mysql]# tail -10 mysql/scripts/master/logs/mysql_switch.log
2019-08-09 07:09:16 The mycheck.sh, mysql is down, after switch...
2019-08-09 07:09:19 The mystop.sh, master sync ok...
[root@localhost mysql]# tail -10 mysql/scripts/slave/logs/mysql_switch.log
2019-08-09 07:09:18 The mymaster.sh, slave sync ok...
File Position Binlog_Do_DB Binlog_Ignore_DB Executed_Gtid_Set
mysql-bin.000010 586 mydatabase mysql,test,information_schema
2019-08-09 07:09:18 The mymaster.sh, Sync pos file sucess.
<-----1.master端数据库宕机(中止mysqld数据库服务),发生:(1)master端keepalived被中止;(2)vip飘到slave端,并调用mymaster.sh脚本停止slave进程复制,相当于服务切换至slave端。
[root@localhost mysql]# docker exec -it mysql-master systemctl start mysqld
[root@localhost mysql]# docker exec -it mysql-master systemctl start keepalived
[root@localhost mysql]# tail -20 mysql/scripts/master/logs/mysql_switch.log
2019-08-09 07:15:15 This mybackup.sh, New_ReM_File:mysql-bin.000010,New_ReM_Position:586
*************************** 1. row ***************************
......
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
2019-08-09 07:15:15 The mybackup.sh, Sync pos file sucess...
<-----2.恢复master端数据库(启动mysqld数据库服务)和keepalived服务,发生:master端调用mybackup.sh脚本启动slave进程复制,相当于同步复制切换至master端。
[root@localhost mysql]# docker exec -it mysql-slave systemctl stop mysqld
[root@localhost mysql]# tail -20 mysql/scripts/slave/logs/mysql_switch.log
......
2019-08-09 07:19:19 The mycheck.sh, mysql is down, after switch...
2019-08-09 07:19:22 The mystop.sh, master sync ok...
[root@localhost mysql]# tail -20 mysql/scripts/master/logs/mysql_switch.log
2019-08-09 07:19:21 The mymaster.sh, slave sync ok...
File Position Binlog_Do_DB Binlog_Ignore_DB Executed_Gtid_Set
mysql-bin.000010 586 mydatabase mysql,test,information_schema
2019-08-09 07:19:21 The mymaster.sh, Sync pos file sucess.
<-----3.slave端数据库宕机
[root@localhost mysql]# docker exec -it mysql-slave systemctl start mysqld
[root@localhost mysql]# docker exec -it mysql-slave systemctl start keepalived
[root@localhost mysql]# tail -20 mysql/scripts/slave/logs/mysql_switch.log
2019-08-09 07:23:24 This mybackup.sh, New_ReM_File:mysql-bin.000010,New_ReM_Position:586
*************************** 1. row ***************************
......
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
2019-08-09 07:23:24 The mybackup.sh, Sync pos file sucess...
2019-08-09 07:23:34 The mycheck.sh, mysql is running...
<-----4.恢复slave端数据库文件详情
docker-compose
docker-compose.yml
version: '3'
services:
mysql-master:
image: 'oracle/mysql:5.7'
hostname: master
restart: always
container_name: mysql-master
privileged: true
volumes:
- ./mysql/master/data:/var/lib/mysql
- ./mysql/scripts:/etc/keepalived/mysql
- ./mysql/master/config/my.cnf:/etc/my.cnf
- ./mysql/master/config/mysqlenv:/root/.mysqlenv
- ./mysql/master/config/keepalived.conf:/etc/keepalived/keepalived.conf
- ./mysql/master/init:/docker-entrypoint-initdb.d/
networks:
extnetwork:
ipv4_address: 172.19.0.2
ports:
- '3307:3306'
environment:
- MYSQL_ROOT_PASSWORD=123456
mysql-slave:
image: 'oracle/mysql:5.7'
hostname: slave
restart: always
container_name: mysql-slave
privileged: true
volumes:
- ./mysql/slave/data:/var/lib/mysql
- ./mysql/scripts:/etc/keepalived/mysql
- ./mysql/slave/config/my.cnf:/etc/my.cnf
- ./mysql/slave/config/mysqlenv:/root/.mysqlenv
- ./mysql/slave/config/keepalived.conf:/etc/keepalived/keepalived.conf
- ./mysql/slave/init:/docker-entrypoint-initdb.d/
networks:
extnetwork:
ipv4_address: 172.19.0.3
ports:
- '3308:3306'
environment:
- MYSQL_ROOT_PASSWORD=123456
volumes:
data:
driver: local
networks:
extnetwork:
ipam:
config:
- subnet: 172.19.0.0/16keepalived.conf
Master
! Configuration File for keepalived
global_defs {
router_id KeepAlive_Mysql
# 标识,主从一致
}
vrrp_script check_run {
script "/etc/keepalived/mysql/mycheck.sh"
# Mysql状态检查脚本
interval 10
}
vrrp_sync_group VG1 {
group {
VI_1
}
}
vrrp_instance VI_1 {
state BACKUP
# 注意,主从两端都配置成了backup,因为使用了nopreempt,即非抢占模式
interface eth0
virtual_router_id 51
# 分组,主从相同
priority 100
# 优先级,这个高一点则先把它作为master
advert_int 1
nopreempt
# 不主动抢占资源,设置非抢占模式
authentication {
# 主从一致
auth_type PASS
auth_pass 123456
}
track_script {
check_run
}
notify_master /etc/keepalived/mysql/mymaster.sh
notify_backup /etc/keepalived/mysql/mybackup.sh
notify_stop /etc/keepalived/mysql/mystop.sh
virtual_ipaddress {
172.19.0.110/24 brd 172.19.0.255 dev eth0 label eth0:0
# 虚拟IP地址
}
}Slave
! Configuration File for keepalived
global_defs {
router_id KeepAlive_Mysql
}
vrrp_script check_run {
script "/etc/keepalived/mysql/mycheck.sh"
interval 10
}
vrrp_sync_group VG1 {
group {
VI_1
}
}
vrrp_instance VI_1 {
state BACKUP
interface eth0
virtual_router_id 51
priority 90
advert_int 1
nopreempt
authentication {
auth_type PASS
auth_pass 123456
}
track_script {
check_run
}
notify_master /etc/keepalived/mysql/mymaster.sh
notify_backup /etc/keepalived/mysql/mybackup.sh
notify_stop /etc/keepalived/mysql/mystop.sh
virtual_ipaddress {
172.19.0.110/24 brd 172.19.0.255 dev eth0 label eth0:0
}
}mycheck
#!/bin/sh
##################################################
#File Name : mycheck.sh
#Date : 2019-08-07
#Description: mysql is working MYSQL_OK is 1
# mysql is down MYSQL_OK is 0
#Writer :by L.H.W
##################################################
BASEPATH=/etc/keepalived/mysql/$HOSTNAME
LOGSPATH=$BASEPATH/logs
[[ -d $LOGSPATH ]] || mkdir -p $LOGSPATH
CHECK_TIME=3
MYSQL_OK=1
source /root/.mysqlenv
function check_mysql_helth(){
$mysql -e "show status;" >/dev/null 2>&1
if [ $? = 0 ] ;then
MYSQL_OK=1
else
MYSQL_OK=0
fi
return $MYSQL_OK
}
while [ $CHECK_TIME -ne 0 ]
do
CHECK_TIME=$((CHECK_TIME-1))
check_mysql_helth
if [ $MYSQL_OK = 1 ] ; then
CHECK_TIME=0
echo "$(date "+%Y-%m-%d %H:%M:%S") The mycheck.sh, mysql is running..." >> $LOGSPATH/mysql_switch.log
exit 0
fi
if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 0 ];then
echo "$(date "+%Y-%m-%d %H:%M:%S") The mycheck.sh, mysql is down, after switch..." >> $LOGSPATH/mysql_switch.log
systemctl stop keepalived
exit 1
fi
sleep 1
donemymaster
#!/bin/sh
##################################################
#File Name : mymaster.sh
#Date : 2019-08-07
#Description: First determine whether synchronous
# replication is performed, and if no
# execution is completed, wait for 1
# minutes. Log logs and POS after
# switching, and record files synchronously.
#Writer :by L.H.W
##################################################
BASEPATH=/etc/keepalived/mysql/$HOSTNAME
LOGSPATH=$BASEPATH/logs
[[ -d $LOGSPATH ]] || mkdir -p $LOGSPATH
source /root/.mysqlenv
$mysql -e "show slave status\G" > $LOGSPATH/mysqlslave.states
Master_Log_File=`cat $LOGSPATH/mysqlslave.states | grep -w Master_Log_File | awk -F": " '{print $2}'`
Relay_Master_Log_File=`cat $LOGSPATH/mysqlslave.states | grep -w Relay_Master_Log_File | awk -F": " '{print $2}'`
Read_Master_Log_Pos=`cat $LOGSPATH/mysqlslave.states | grep -w Read_Master_Log_Pos | awk -F": " '{print $2}'`
Exec_Master_Log_Pos=`cat $LOGSPATH/mysqlslave.states | grep -w Exec_Master_Log_Pos | awk -F": " '{print $2}'`
i=1
while true
do
if [ $Master_Log_File = $Relay_Master_Log_File ] && [ $Read_Master_Log_Pos -eq $Exec_Master_Log_Pos ];then
echo "$(date "+%Y-%m-%d %H:%M:%S") The mymaster.sh, slave sync ok... " >> $LOGSPATH/mysql_switch.log
break
else
sleep 1
if [ $i -gt 60 ];then
break
fi
continue
let i++
fi
done
$mysql -e "stop slave;"
$mysql -e "set global innodb_support_xa=0;"
$mysql -e "set global sync_binlog=0;"
$mysql -e "set global innodb_flush_log_at_trx_commit=0;"
$mysql -e "flush logs;GRANT ALL PRIVILEGES ON *.* TO 'repl'@'%' IDENTIFIED BY '123456';flush privileges;"
$mysql -e "show master status;" > $LOGSPATH/master_status.txt
cat $LOGSPATH/master_status.txt >> $LOGSPATH/mysql_switch.log
# sync pos file
/usr/bin/ssh -o StrictHostKeyChecking=no root@$REMOTE_IP date
/usr/bin/scp $LOGSPATH/master_status.txt root@$REMOTE_IP:/tmp/backup_master.status
echo "$(date "+%Y-%m-%d %H:%M:%S") The mymaster.sh, Sync pos file sucess." >> $LOGSPATH/mysql_switch.logmybackup
#!/bin/sh
##################################################
#File Name : mybackup.sh
#Date : 2019-08-07
#Description: Empty the slave configuration, retrieve
# the remote log file and Pos, and open
# the synchronization
#Writer :by L.H.W
##################################################
BASEPATH=/etc/keepalived/mysql/$HOSTNAME
LOGSPATH=$BASEPATH/logs
[[ -d $LOGSPATH ]] || mkdir -p $LOGSPATH
source /root/.mysqlenv
CHECK_TIME=6
SLAVE_OK=1
$mysql -e "GRANT ALL PRIVILEGES ON *.* TO 'repl'@'%' IDENTIFIED BY '123456';flush privileges;"
$mysql -e "set global innodb_support_xa=0;"
$mysql -e "set global sync_binlog=0;"
$mysql -e "set global innodb_flush_log_at_trx_commit=0;"
$mysql -e "flush logs;"
$mysql -e "reset slave all;"
function check_slave(){
LOGFILE=$1
IO_STATUS=`grep Slave_IO_Running: $LOGFILE| awk -F": " '{print $2}'`
SQL_STATUS=`grep Slave_SQL_Running: $LOGFILE| awk -F": " '{print $2}'`
if [[ "$IO_STATUS" = "Yes" ]] && [[ "$SQL_STATUS" = "Yes" ]] ;then
SLAVE_OK=1
else
SLAVE_OK=0
fi
return $SLAVE_OK
}
while [ $CHECK_TIME -ne 0 ]
do
CHECK_TIME=$((CHECK_TIME-1))
# 存在同步位置信息文件则尝试进行从库同步
if [ -f /tmp/backup_master.status ]; then
New_ReM_File=`cat /tmp/backup_master.status | grep -v File |awk '{print $1}'`
New_ReM_Position=`cat /tmp/backup_master.status | grep -v File |awk '{print $2}'`
echo "$(date "+%Y-%m-%d %H:%M:%S") This mybackup.sh, New_ReM_File:$New_ReM_File,New_ReM_Position:$New_ReM_Position" >> $LOGSPATH/mysql_switch.log
$mysql -e "change master to master_host='$REMOTE_IP',master_port=3306,master_user='repl',master_password='123456',master_log_file='$New_ReM_File',master_log_pos=$New_ReM_Position;"
$mysql -e "start slave;"
fi
SLAVE_LOGFILE=$LOGSPATH/slave_status.txt
$mysql -e "show slave status\G;" > $SLAVE_LOGFILE
check_slave $SLAVE_LOGFILE
cat $SLAVE_LOGFILE >> $LOGSPATH/mysql_switch.log
# 同步成功则正常退出
if [ $SLAVE_OK = 1 ] ; then
CHECK_TIME=0
echo "$(date "+%Y-%m-%d %H:%M:%S") The mybackup.sh, Sync pos file sucess..." >> $LOGSPATH/mysql_switch.log
rm -f /tmp/backup_master.status
exit 0
fi
# 同步失败 且 尝试次数超过CHECK_TIME次数
if [ $SLAVE_OK -eq 0 ] && [ $CHECK_TIME -eq 0 ];then
echo "$(date "+%Y-%m-%d %H:%M:%S") The scripts mybackup.sh running error..." >> $LOGSPATH/mysql_switch.log
exit 1
fi
sleep 15
donemystop
#!/bin/sh
##################################################
#File Name : mystop.sh
#Date : 2019-08-07
#Description: Set parameters to ensure that the data
# is not lost, and finally check to see
# if there are still write operations,
# the last 1 minutes to exit
#Writer :by L.H.W
##################################################
BASEPATH=/etc/keepalived/mysql/$HOSTNAME
LOGSPATH=$BASEPATH/logs
[[ -d $LOGSPATH ]] || mkdir -p $LOGSPATH
source /root/.mysqlenv
$mysql -e "GRANT ALL PRIVILEGES ON *.* TO 'repl'@'%' IDENTIFIED BY '123456';flush privileges;"
$mysql -e "set global innodb_support_xa=1;"
$mysql -e "set global sync_binlog=1;"
$mysql -e "set global innodb_flush_log_at_trx_commit=1;"
$mysql -e "show master status\G" > $LOGSPATH/mysqlmaster0.states
M_File1=`cat $LOGSPATH/mysqlmaster0.states | awk -F': ' '/File/{print $2}'`
M_Position1=`cat $LOGSPATH/mysqlmaster0.states | awk -F': ' '/Position/{print $2}'`
sleep 2
$mysql -e "show master status\G" > $LOGSPATH/mysqlmaster1.states
M_File2=`cat $LOGSPATH/mysqlmaster1.states | awk -F': ' '/File/{print $2}'`
M_Position2=`cat $LOGSPATH/mysqlmaster1.states | awk -F': ' '/Position/{print $2}'`
i=1
while true
do
if [ $M_File1 = $M_File2 ] && [ $M_Position1 -eq $M_Position2 ];then
echo "$(date "+%Y-%m-%d %H:%M:%S") The mystop.sh, master sync ok..." >> $LOGSPATH/mysql_switch.log
exit 0
else
sleep 1
if [ $i -gt 60 ];then
break
fi
continue
let i++
fi
done
echo "$(date "+%Y-%m-%d %H:%M:%S") The mystop.sh, master sync exceed one minutes..." >> $LOGSPATH/mysql_switch.logmy.cnf
Master
[mysqld]
log-bin=mysql-bin
lower_case_table_names = 1
default-time-zone = '+08:00'
character-set-server = utf8
event_scheduler = on
server-id= 1
expire_logs_days = 10
binlog-ignore-db = mysql
binlog-ignore-db = test
binlog-ignore-db = information_schema
binlog-do-db = mydatabase
skip-host-cache
skip-name-resolve
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
secure-file-priv=/var/lib/mysql-files
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/lib/mysql/mysqld.pidSlave
[mysqld]
log-bin=mysql-bin
lower_case_table_names = 1
default-time-zone = '+08:00'
character-set-server = utf8
event_scheduler = on
server-id= 2
expire_logs_days = 10
binlog-ignore-db = mysql
binlog-ignore-db = test
binlog-ignore-db = information_schema
binlog-do-db = mydatabase
skip-host-cache
skip-name-resolve
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
secure-file-priv=/var/lib/mysql-files
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/lib/mysql/mysqld.pidmysqlenv
Master
export REMOTE_IP=172.19.0.3
export mysql='/usr/bin/mysql -uroot -p123456'Slave
export REMOTE_IP=172.19.0.2
export mysql='/usr/bin/mysql -uroot -p123456'
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