概述
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
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 |
|---|---|---|
| 1 | Mycat1 |
192.168.110.145 |
| 2 | Mycat2 |
192.168.110.150 |
| 3 | HAProxy(master) |
192.168.110.151 |
| 4 | Keepalived(master) |
192.168.110.151 |
| 5 | HAProxy(backup) |
192.168.110.152 |
| 6 | Keepalived(backup) |
192.168.110.152 |
安装配置 HAProxy
各版本下载地址：
https://src.fedoraproject.org/repo/pkgs/haproxy/本文使用版本为：1.5.18
下载地址：
https://src.fedoraproject.org/repo/pkgs/haproxy/haproxy-1.5.18.tar.gz/21d35f114583ef731bc96af05b46c75a/haproxy-1.5.18.tar.gz安装步骤：
将下载好的
HAProxy安装包传到/usr/local/src目录下进行解压cd /usr/local/src wget https://src.fedoraproject.org/repo/pkgs/haproxy/haproxy-1.5.18.tar.gz/21d35f114583ef731bc96af05b46c75a/haproxy-1.5.18.tar.gz tar -zxvf haproxy-1.5.18.tar.gz cd /usr/local/src/haproxy-1.5.18安装依赖插件
# Ubuntu 依次执行 sudo apt-get install -y gcc sudo apt-get install -y g++ sudo apt-get install -y libssl-dev sudo apt-get install -y daemon sudo apt-get install -y make # CentOS yum install -y gcc openssl-devel popt-devel查看内核版本，进行编译
# 查看内核版本 uname -r # 查看 haproxy README文件对应的系统内核版本 cat /usr/local/haproxy/READMEmake TARGET=linux2628 PREFIX=/usr/local/haproxy ARCH=x86_64ARGET：内核版本，使用uname -r查看内核，结合查看haproxy README文件对应的系统内核版本ARCH：系统位数PREFIX：为haprpxy安装路径
编译完成，进行安装
make install PREFIX=/usr/local/haproxy安装完成
- 创建配置目录
mkdir -p /usr/data/haproxy/- 创建
HAProxy配置文件
vim /usr/local/haproxy/haproxy.conf配置内容如下：
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 # HAProxy 监听配置 listen proxy_status # 监听代理端口 bind :48066 mode tcp balance roundrobin # 监听Mycat服务地址 server mycat_1 192.168.110.145:8066 check inter 10s server mycat_2 192.168.110.150:8066 check inter 10s # HAProxy 控制台配置 frontend admin_stats bind :7777 mode http stats enable option httplog maxconn 10 stats refresh 30s stats uri /admin stats auth admin:123456 stats hide-version stats admin if TRUE启动验证
启动
HAProxy/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.conf查看
HAProxy进程ps -ef|grep haproxy打开浏览器访问
http://192.168.110.151:7777/admin输入配置文件中的账号密码进行访问。
admin/123456
验证负载均衡，通过
HAProxy访问Mycatmysql -umycat -p123456 -h 192.168.110.151 -P 48066
HAProxy(backup) 192.168.110.152如上配置
配置Keepalived
各版本下载地址：
https://www.keepalived.org/download.html本文使用版本为：1.4.2
下载地址：
https://www.keepalived.org/software/keepalived-1.4.2.tar.gz安装步骤：
将下载好的
Keepalived安装包传到/usr/local/src目录下进行解压cd /usr/local/src wget https://www.keepalived.org/software/keepalived-1.4.2.tar.gz tar -zxvf keepalived-1.4.2.tar.gz cd /usr/local/src/keepalived-1.4.2安装依赖插件
# Ubuntu 依次执行 sudo apt-get install -y gcc sudo apt-get install -y g++ sudo apt-get install -y libssl-dev sudo apt-get install -y daemon sudo apt-get install -y make # CentOS yum install -y gcc openssl-devel popt-devel进入解压后的目录，进行配置
cd /usr/local/src/keepalived-1.4.2 ./configure --prefix=/usr/local/keepalived进行编译，完成后进行安装
cd /usr/local/src/keepalived-1.4.2 make && make install运行前配置，将
keepalived设置为系统服务Ubuntu配置mkdir /etc/keepalived mkdir /etc/sysconfig cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ cp /usr/local/src/keepalived-1.4.2/keepalived/etc/init.d/keepalived /etc/init.d/ cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ ln -s /usr/local/keepalived/sbin/keepalived /usr/sbin/ ln -s /usr/local/keepalived/sbin/keepalived /sbin/CentOSmkdir /etc/keepalived cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ cp /usr/local/src/keepalived-1.4.2/keepalived/etc/init.d/keepalived /etc/init.d/ cp /usr/local/src/keepalived-1.4.2/keepalived/etc/sysconfig/keepalived /etc/default/keepalived cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
修改配置文件
vim /etc/keepalived/keepalived.conf配置文件内容如下：
! 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，在HAProxy之上设定一个虚拟IP，可以在该网段内任意指定未使用的IP 192.168.110.200 } } virtual_server 192.168.110.200 48066 { delay_loop 6 lb_algo rr lb_kind NAT persistence_timeout 50 protocol TCP # HAProxy 地址 real_server 192.168.110.151 48066 { weight 1 TCP_CHECK { connect_timeout 3 retry 3 delay_before_retry 3 } } real_server 192.168.110.152 48066 { weight 1 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 } } }配置重载
systemctl daemon-reload启动验证
启动
Keepalivedservice keepalived start启动后可以看到在
ens33真实IP:192.168.110.151下面挂载了一个虚拟IP:192.168.110.200root@ubuntu:~# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 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: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 00:0c:29:9b:eb:14 brd ff:ff:ff:ff:ff:ff inet 192.168.110.151/24 brd 192.168.110.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.110.200/32 scope global ens33 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe9b:eb14/64 scope link 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:d3:e0:c7 brd ff:ff:ff:ff:ff:ff inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0 valid_lft forever preferred_lft forever查看
Keepalived状态service keepalived status登录验证
mysql -umycat -p123456 -h 192.168.110.200 -P 48066
测试高可用
- 关闭
Mycat1
通过虚拟
IP查询数据# 通过Keepalived登录数据库 mysql -umycat -p123456 -h 192.168.110.200 -P 48066 # 切换数据库 use TESTDB; # 执行SQL命令 show tables;root@ubuntu-mysql-master:~# mysql -umycat -p123456 -h 192.168.110.200 -P 48066 mysql: [Warning] Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.6.29-mycat-1.6.7.6-release-20220524173810 MyCat Server (OpenCloudDB) Copyright (c) 2000, 2021, Oracle and/or its affiliates. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> use TESTDB; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> show tables; +------------------+ | Tables_in_orders | +------------------+ | customer | | dict_order_type | | login_info | | orders | | orders_detail | | orders_ware_info | | payment_info | +------------------+ 7 rows in set (0.00 sec)
- 关闭
