在实际项目中，Mycat 服务也需要考虑高可用性，如果 Mycat 所在服务器出现宕机，或 Mycat 服

务故障，需要有备机提供服务，需要考虑 Mycat 集群。

1、 高可用方案

使用 HAProxy + Keepalived 配合两台 Mycat 搭起 Mycat 集群，实现高可用性。

HAProxy实现了 MyCat 多节点的集群高可用和负载均衡

HAProxy 自身的高可用则可以通过 Keepalived 来实现。

角色

ip

mycat01

192.168.199.217

mycat02

192.168.199.120

HA(主)

192.168.199.174

keepalive(主机)

192.168.199.174

HA(主)

192.168.199.199

keepalive(主机

192.168.199.199

先配置好mycat并且启动mycat

2 安装配置 HAProxy

1、 安装 HAProxy

2解压到/usr/local/src

3进入解压后的目录，查看内核版本，进行编译

[root@mycat05 software]# cd /usr/local/src/haproxy-1.5.18/

[root@mycat05 haproxy-1.5.18]# uname -r

3.10.0-957.el7.x86_64

[root@mycat05 haproxy-1.5.18]# make TARGET=linux310 PREFIX=/usr/local/haproxy ARCH=x86_64

# ARGET=linux310，内核版本，使用uname -r查看内核，如：3.10.0-957.el7，此时该参数就为linux310；

#ARCH=x86_64，系统位数；

#PREFIX=/usr/local/haprpxy #/usr/local/haprpxy，为haprpxy安装路径。

4编译完成后，进行安装

make install PREFIX=/usr/local/haproxy

5安装完成后，创建目录、创建HAProxy配置文件

mkdir -p /usr/data/haproxy/

vim /usr/local/haproxy/haproxy.conf

6向配置文件中插入以下配置信息,并保存

globallog127.0.0.1local0

#log127.0.0.1local1 notice

#log loghost local0 info

maxconn4096chroot/usr/local/haproxy

pidfile/usr/data/haproxy/haproxy.pid

uid99gid99daemon

#debug

#quiet

defaults

logglobalmode tcp

option abortonclose

option redispatch

retries3maxconn2000timeout connect5000timeout client50000timeout server50000listen proxy_status

bind :48066mode tcp

balance roundrobin

server mycat_1192.168.140.128:8066check inter 10s

server mycat_2192.168.140.127:8066check inter 10s

frontend admin_stats

bind :7777mode http

stats enable

option httplog

maxconn10stats refresh 30s

stats uri/admin

stats auth admin:123123 //登陆账户and密码stats hide-version

stats adminif TRUE

2、 启动验证

1启动HAProxy

/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.conf

2查看HAProxy进程

ps -ef|grep haproxy

3打开浏览器访问

如果Mycat主备机均已启动，则可以看到如下图

4验证负载均衡，通过HAProxy访问Mycat

在HAProxy主机上执行(192.168.199.174HA的主机地址)

[root@mycat05 haproxy-1.5.18]# mysql -umycat -p123456 -h 192.168.199.174 -P 48066

3 配置 Keepalived

1准备好Keepalived安装包，传到/opt目录下

2解压到/usr/local/src

tar -zxvf keepalived-1.4.2.tar.gz -C /usr/local/src

3安装依赖插件

yum install -y gcc openssl-devel popt-devel

4进入解压后的目录，进行配置，进行编译

cd /usr/local/src/keepalived-1.4.2

./configure --prefix=/usr/local/keepalived

5进行编译，完成后进行安装

make && make install

6运行前配置

cp /usr/local/src/keepalived-1.4.2/keepalived/etc/init.d/keepalived /etc/init.d/

mkdir /etc/keepalived

cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

cp /usr/local/src/keepalived-1.4.2/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

7修改配置文件

vim /etc/keepalived/keepalived.conf

#修改内容如下! Configuration File forkeepalived

global_defs {

notification_email {

xlcocoon@foxmail.com

}

notification_email_from keepalived@showjoy.com

smtp_server127.0.0.1smtp_connect_timeout30router_id LVS_DEVEL

vrrp_skip_check_adv_addr

vrrp_garp_interval0vrrp_gna_interval0}

vrrp_instance VI_1 {

#主机配MASTER，备机配BACKUP

state MASTER

#所在机器网卡interfaceens33

virtual_router_id51#数值越大优先级越高

priority100advert_int1authentication {

auth_type PASS

auth_pass1111}

virtual_ipaddress {

#虚拟IP

192.168.199.111} }

virtual_server192.168.199.111 48066{

delay_loop6lb_algo rr

lb_kind NAT

persistence_timeout50protocol TCP

real_server192.168.199.174 48066{ # HA的地址(主机)

weight1rTCP_CHECK {

connect_timeout3retry3delay_before_retry3} }

real_server192.168.199.199 48600{#HA地址(备机r)

weight1TCP_CHECK {

connect_timeout3nb_get_retry3delay_before_retry3}

} }

8、启动Keepalived

同时启动备机上的HA

service keepalived start

9、登录验证

mysql -umycat -p123456 -h 192.168.199.111 -P 48066

192.168.199.111 ：虚拟ip

此时是：

HA隐藏mycat的ip

KeepAlive隐藏HA的ip

4 测试高可用

1关闭mycat

2通过虚拟ip查询数据

mysql -umycat -p123456 -h 192.168.199.111 -P 48066

mysql> select * fromorders;

ERROR2013(HY000): Lost connection to MySQL server during query

mysql> select * fromorders;

ERROR2006(HY000): MySQL server has gone away

No connection. Trying to reconnect...

Connection id:2Current database: TESTDB+--------+------------+-------------+-----------+

| id | order_type | customer_id | amount |

+--------+------------+-------------+-----------+

| 1 | 101 | 100 | 100100.00 |

| 2 | 101 | 100 | 100300.00 |

| 6 | 102 | 100 | 100020.00 |

| 3 | 101 | 101 | 120000.00 |

| 4 | 101 | 101 | 103000.00 |

| 5 | 102 | 101 | 100400.00 |

| 400100 | 102 | 101 | 1000.00 |

| 400101 | 102 | 101 | 1000.00 |

+--------+------------+-------------+-----------+

8 rows in set (1.46 sec)