基于 HA 机制的 Mycat 高可用
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。
高可用方案
我们可以使用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，而 HAProxy 自身的高可用则可以通过Keepalived 来实现。
|
编号 |
角色 |
IP 地址 |
机器名 |
|
1 |
Mycat1 |
192.168.140.128 |
host79.atguigu |
|
2 |
Mycat2 |
192.168.140.127 |
host80.atguigu |
|
3 |
HAProxy（master） |
192.168.140.126 |
host81.atguigu |
|
4 |
Keepalived（master） |
192.168.140.126 |
host81.atguigu |
|
5 |
HAProxy（backup） |
192.168.140.125 |
host82.atguigu |
|
6 |
Keepalived（backup） |
192.168.140.125 |
host82.atguigu |
安装配置 HAProxy
1、 安装 HAProxy
#1准备好HAProxy安装包，传到/opt目录下 #2解压到/usr/local/src tar -zxvf haproxy-1.5.18.tar.gz -C /usr/local/src #3进入解压后的目录，查看内核版本，进行编译cd /usr/local/src/haproxy-1.5.18 uname -r 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：3.10.0-514.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 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://192.168.140.125:7777/admin
#在弹出框输入用户名：admin密码：123123
#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
mysql -umycat -p123456 -h 192.168.140.126 -P 48066
配置 Keepalived
1、 安装 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 #3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 #4进行编译，完成后进行安装make && make install #5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/ #6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 { xlcocoon@foxmail.com } notification_email_from keepalived@showjoy.com 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 192.168.140.200 } } virtual_server 192.168.140.200 48066 { delay_loop 6 lb_algo rr lb_kind NAT persistence_timeout 50 protocol TCP real_server 192.168.140.125 48066 { weight 1 TCP_CHECK { connect_timeout 3 retry 3 delay_before_retry 3 } } real_server 192.168.140.126 48600 { weight 1 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } }
2、 启动验证
#1启动Keepalived
service keepalived start
#2登录验证
mysql -umycat -p123456 -h 192.168.140.200 -P 48066
测试高可用
#1关闭mycat
#2通过虚拟ip查询数据
mysql -umycat -p123456 -h 192.168.140.200 -P 48066