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

[[email protected] software]# cd /usr/local/src/haproxy-1.5.18/
[[email protected] haproxy-1.5.18]# uname -r
3.10.0-957.el7.x86_64
[[email protected] 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

global
 log 127.0.0.1 local0
 #log 127.0.0.1 local1 notice
 #log loghost local0 info
 maxconn 4096
 chroot /usr/local/haproxy
 pidfile /usr/data/haproxy/haproxy.pid
 uid 99
 gid 99
 daemon
 #debug
 #quiet
defaults
 log global
 mode tcp
 option abortonclose
 option redispatch
 retries 3
 maxconn 2000
 timeout connect 5000
 timeout client 50000
 timeout server 50000
listen proxy_status 
bind :48066
 mode tcp
 balance roundrobin
 server mycat_1 192.168.140.128:8066 check inter 10s
 server mycat_2 192.168.140.127:8066 check inter 10s
frontend admin_stats 
bind :7777
 mode http
 stats enable
 option httplog
 maxconn 10
 stats refresh 30s
 stats uri /admin
 stats auth admin:123123 //登陆账户and密码
 stats hide-version
 stats admin if 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 http://192.168.199.174:7777/admin

 

 

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）

[[email protected] haproxy-1.5.18]# mysql -umycat -p123456 -h 192.168.199.174 -P 48066

 

 

 

 

3 配置 Keepalived 

下载地址：https://www.keepalived.org/software/

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 for keepalived
global_defs {
 notification_email {
 [email protected]
 }
 notification_email_from [email protected]
 smtp_server 127.0.0.1
 smtp_connect_timeout 30
 router_id LVS_DEVEL
 vrrp_skip_check_adv_addr
 vrrp_garp_interval 0
 vrrp_gna_interval 0
}
vrrp_instance VI_1 {
 #主机配MASTER，备机配BACKUP
state MASTER
#所在机器网卡
 interface ens33
virtual_router_id 51
#数值越大优先级越高
 priority 100
 advert_int 1
 authentication {
 auth_type PASS
 auth_pass 1111
 }
virtual_ipaddress {
#虚拟IP
 192.168.199.111
 } }
virtual_server 192.168.199.111 48066 {
 delay_loop 6
 lb_algo rr
 lb_kind NAT
 persistence_timeout 50
 protocol TCP
 real_server 192.168.199.174 48066 { # HA的地址（主机）
 weight 1r
 TCP_CHECK {
 connect_timeout 3
 retry 3
 delay_before_retry 3
 } }
real_server 192.168.199.199 48600 {#HA地址（备机r）
 weight 1
 TCP_CHECK {
 connect_timeout 3
 nb_get_retry 3
 delay_before_retry 3
 }
 } }

 

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 * from orders;
ERROR 2013 (HY000): Lost connection to MySQL server during query


mysql> select * from orders;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    2
Current 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)