目录
一、介绍
有些情况下，可能MySQL Router不便装在每个应用所在的服务器上，那么这时候要解决MySQL Router的单点故障，就需要用到keepalived或者pacemaker了，本文介绍了MySQL Router HA通过keepalived来实现。
二、环境准备
| IP地址 | 角色 |
|---|---|
| 172.16.8.53 | MySQL Router+MASTER |
| 172.16.8.68 | MySQL Router+BACKUP |
| 172.16.8.24 | VIP |
keepalived版本：2.0.18
三、安装步骤
- 下载软件包，解压
mkdir /software
wget https://www.keepalived.org/software/keepalived-2.0.18.tar.gz -P /software
tar -zxvf /software/keepalived-2.0.18.tar.gz ; cd /software/keepalived- 源码安装
yum -y install openssl* libnl‐dev* gcc-c++
./configure --prefix=/usr/local/keepalived
make
make install- 配置keepalived
mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /data/keepalived-2.0.18/keepalived/etc/init.d/keepalived /etc/init.d/
cp /data/keepalived-2.0.18/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/- 修改keepalived配置文件
MASTER
! Configuration File for keepalived
global_defs {
notification_email {
zhenweizheng@upchina.com
}
notification_email_from 13912345678@139.com
smtp_server smtp.139.com
smtp_connect_timeout 30
router_id Router1
vrrp_skip_check_adv_addr
# vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script chk_mysqlrouter {
script "/usr/bin/killall -0 /usr/bin/mysqlrouter" # check the haproxy process
interval 2 # every 2 seconds
weight 2 # add 2 points if OK
fall 2
}
vrrp_instance VI_1 {
state MASTER
interface ens160
virtual_router_id 51
priority 102
advert_int 1
virtual_ipaddress {
172.16.8.24
}
track_script {
chk_mysqlrouter
}
notify_master "/usr/bin/python /data/keepalived_monitor/keepalived_notify.py master 172.16.8.53 172.168.8.24"
notify_backup "/usr/bin/python /data/keepalived_monitor/keepalived_notify.py backup 172.16.8.53 172.168.8.24"
}BACKUP
! Configuration File for keepalived
global_defs {
notification_email {
xxx@xxx.com
}
notification_email_from 13912345678@139.com
smtp_server smtp.139.com
smtp_connect_timeout 30
router_id Router2
vrrp_skip_check_adv_addr
# vrrp_strict
vrrp_garp_interval 0
vrrp_gna_interval 0
}
vrrp_script chk_mysqlrouter {
script "/usr/bin/killall -0 /usr/bin/mysqlrouter" # check the haproxy process
interval 2 # every 2 seconds
weight 2 # add 2 points if OK
fall 2
}
vrrp_instance VI_1 {
state BACKUP
interface ens160
virtual_router_id 51
priority 101
advert_int 1
virtual_ipaddress {
172.16.8.24
}
track_script {
chk_mysqlrouter
}
notify_master "/usr/bin/python /data/keepalived_monitor/keepalived_notify.py master 172.16.8.68 172.168.8.24"
notify_backup "/usr/bin/python /data/keepalived_monitor/keepalived_notify.py backup 172.16.8.68 172.168.8.24"
}/usr/bin/killall -0 /usr/bin/mysqlrouter，每2秒钟会执行一次，监测mysqlrouter进程是否存在，一旦超过2次不正常，则会且换vip到BACKUP，并且执行keepalived_notify.py邮件报警脚本发送告警邮件
- 启动keepalived
systemctl start keepalived
systemctl enable keepalived启动参数说明：
使用systemctl start keepalived命令启动服务时，默认会将/etc/sysconfig/keepalived文件中KEEPALIVED_OPTIONS参数作为keepalived服务启动时的参数，并从/etc/keepalived/目录下加载keepalived.conf配置文件，或用-f参数指定配置文件的位置。
- 查看VIP绑定情况
MASTER
[root@node3 keepalived_monitor]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:50:56:99:45:ad brd ff:ff:ff:ff:ff:ff
inet 172.16.8.53/24 brd 172.16.8.255 scope global noprefixroute ens160
valid_lft forever preferred_lft forever
inet 172.16.8.24/32 scope global ens160
valid_lft forever preferred_lft forever
inet6 fe80::170e:b457:5dbd:d629/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:c3:9f:ab:0e brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 scope global docker0
valid_lft forever preferred_lft forever
4: tunl0@NONE: <NOARP,UP,LOWER_UP> mtu 1440 qdisc noqueue state UNKNOWN group default qlen 1000
link/ipip 0.0.0.0 brd 0.0.0.0
inet 10.233.71.0/32 scope global tunl0
valid_lft forever preferred_lft forever可以看到VIP：172.16.8.24已经绑定到ens160网卡上
BACKUP
[root@node4 mysqlrouter]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens160: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 00:50:56:99:1c:0f brd ff:ff:ff:ff:ff:ff
inet 172.16.8.68/24 brd 172.16.8.255 scope global noprefixroute ens160
valid_lft forever preferred_lft forever
inet6 fe80::25a1:8b8d:a00e:70dd/64 scope link noprefixroute
valid_lft forever preferred_lft forever
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
link/ether 02:42:00:4f:fb:9b brd ff:ff:ff:ff:ff:ff
inet 172.17.0.1/16 scope global docker0
valid_lft forever preferred_lft forever
4: tunl0@NONE: <NOARP,UP,LOWER_UP> mtu 1440 qdisc noqueue state UNKNOWN group default qlen 1000
link/ipip 0.0.0.0 brd 0.0.0.0
inet 10.233.74.64/32 scope global tunl0
valid_lft forever preferred_lft foreverBACKUP是没有绑定VIP的，只有当MASTER发生故障，触发了VIP切换，BACKUP才会绑定VIP
四、邮件告警
邮件告警脚本如下，需要在MASTER和BACKUP上都部署
[root@node3 keepalived_monitor]# cat keepalived_notify.py
#!/usr/bin/python
# -*- coding:utf-8 -*-
import smtplib
from email.mime.text import MIMEText
from email.header import Header
import sys, time, subprocess
# 第三方 SMTP 服务
mail_host="smtp.139.com" #设置服务器
mail_user="13912345678@139.com" #用户名
mail_pass="xxx" #口令
sender = '13912345678@139.com' # 邮件发送者
receivers = ['xxx@xxx.com', 'xxx@xxx.com'] # 接收邮件，可设置为你的QQ邮箱或者其他邮箱
p = subprocess.Popen('hostname', shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
hostname = p.stdout.readline().split('\n')[0]
message_to = ''
for i in receivers:
message_to += i + ';'
def print_help():
note = '''python script.py role ip vip
'''
print(note)
exit(1)
time_stamp = time.strftime('%Y-%m-%d %H:%M:%S',time.localtime(time.time()))
if len(sys.argv) != 4:
print_help()
elif sys.argv[1] == 'master':
message_content = '%s server: %s(%s) change to Master, VIP: %s' %(time_stamp, sys.argv[2], hostname, sys.argv[3])
subject = '%s change to Master -- keepalived notify' %(sys.argv[2])
elif sys.argv[1] == 'backup':
message_content = '%s server: %s(%s) change to Backup, VIP: %s' %(time_stamp, sys.argv[2], hostname, sys.argv[3])
subject = '%s change to Backup -- keepalived notify' %(sys.argv[2])
else:
print_help()
message = MIMEText(message_content, 'plain', 'utf-8')
message['From'] = Header(sender, 'utf-8')
message['To'] = Header(message_to, 'utf-8')
message['Subject'] = Header(subject, 'utf-8')
try:
smtpObj = smtplib.SMTP()
smtpObj.connect(mail_host, 25) # 25 为 SMTP 端口号
smtpObj.login(mail_user,mail_pass)
smtpObj.sendmail(sender, receivers, message.as_string())
print("邮件发送成功")
except smtplib.SMTPException as e:
print("Error: 无法发送邮件")
print(e)五、问题汇总
4.1没有killall命令
解决办法：yum install psmisc
4.2VIP无法ping通
解决办法：关闭防火墙和SELinux，如果要开启防火墙的话，需要开放keepalived的组播端口