Ubuntu下LVS + Keepalived 实现MySQL高可用负载均衡实现

在192.85.1.4上，在终端输入：sudo /usr/local/mysql/bin/mysql -h 192.85.1.10 -u zichen -penter password:62672000正常情况下

LVS Server : 192.85.1.5
Virtual IP : 192.85.1.10
Real Server1 : 192.85.1.4
Real Server2 : 192.85.1.9
在 LVS Server 上安装 ipvsadm 和 keepalived。
$ sudo apt-get install ipvsadm keepalived
使用这两个做配合时，无需配置 ipvsadm，直接修改 keepalived.conf 即可。
$ sudo vim /etc/keepalived/keepalived.conf

global_defs {
router_id LVS_DEVEL
}

vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100 #100为从服务器，主服务器为：101
advert_int 1

authentication {
auth_type PASS
auth_pass 1111
}

virtual_ipaddress {
192.85.1.10
}
}

virtual_server 192.85.1.10 3306{
delay_loop 1 # 每隔 1 秒查询 RealServer 状态
lb_algo wrr # LVS 算法
lb_kind DR # Direct Route
#persistence_timeout 60 # 同一 IP 在 60 秒内分配到同一台 RealServer
protocol TCP # 使用 TCP 协议检查 RealServer 状态

real_server 192.85.1.4 3306{
weight 3 # 权重
TCP_CHECK {
connect_timeout 10 # 10 秒无响应超时
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}

real_server 192.85.1.9 3306 {
weight 3
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 3306
}
}
}}
启动 keepalived 服务。$ sudo service keepalived start #应该先启动mysql集群

检查 ipvsadm 设置。
$ sudo ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.85.1.10:3306 wrr
-> 192.85.1.4:3306 Route 3 0 0
-> 192.85.1.9:3306 Route 3 0 0

在所有 RealServer /etc/rc.local 中添加配置信息后重启
$ sudo nano /etc/rc.local

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

ifconfig lo:0 192.85.1.10 netmask 255.255.255.255 broadcast 192.85.1.10 up
route add -host 192.85.1.10 dev lo:0

echo "0" > /proc/sys/net/ipv4/ip_forward
echo "1" > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" > /proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/all/arp_announce

exit 0

这时我们就可以进行测试了。在Real Server1 上，创建数据库：clustertest,
sudo /usr/local/mysql/bin/mysql -u root -p
密码默认为空
mysql> GRANT ALL ON clustertest.* TO 'zichen'@'$' IDENTIFIED BY '62672000';
mysql> FLUSH PRIVILEGES;
mysql> CREATE DATABASE clustertest;
mysql> USE clustertest;
mysql> CREATE TABLE test(id INT) ENGINE=NDBCLUSTER;
mysql> INSERT INTO test VALUES(1);
mysql> quit;
在 Real Server2上
sudo /usr/local/mysql/bin/mysql -u root -p
密码默认为空
mysql> GRANT ALL ON clustertest.* TO 'zichen'@'$' IDENTIFIED BY '62672000';
mysql> FLUSH PRIVILEGES;
mysql> quit;

在192.85.1.4上，，在终端输入：sudo /usr/local/mysql/bin/mysql -h 192.85.1.10 -u zichen -p
enter password:62672000
正常情况下，应该能进入如下界面：mysql >
mysql > use clustertest;
mysql > show tables;
mysql > select * from test;
mysql > insert into test values (2);
在两个SQL节点上查看数据是否同步。