在實際項目中，Mycat 服務也需要考慮高可用性，如果 Mycat 所在服務器出現宕機，或 Mycat 服

務故障，需要有備機提供服務，需要考慮 Mycat 集群。

1、 高可用方案

使用 HAProxy + Keepalived 配合兩臺 Mycat 搭起 Mycat 集群，實現高可用性。

HAProxy實現了 MyCat 多節點的集群高可用和負載均衡

HAProxy 自身的高可用則可以通過 Keepalived 來實現。

角色

ip

mycat01

192.168.199.217

mycat02

192.168.199.120

HA(主)

192.168.199.174

keepalive(主機)

192.168.199.174

HA(主)

192.168.199.199

keepalive(主機

192.168.199.199

先配置好mycat并且啟動mycat

2 安裝配置 HAProxy

1、 安裝 HAProxy

2解壓到/usr/local/src

3進入解壓后的目錄，查看內核版本，進行編譯

[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，內核版本，使用uname -r查看內核，如：3.10.0-957.el7，此時該參數就為linux310；

#ARCH=x86_64，系統位數；

#PREFIX=/usr/local/haprpxy #/usr/local/haprpxy，為haprpxy安裝路徑。

4編譯完成后，進行安裝

make install PREFIX=/usr/local/haproxy

5安裝完成后，創建目錄、創建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 //登陸賬戶and密碼stats hide-version

stats adminif TRUE

2、 啟動驗證

1啟動HAProxy

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

2查看HAProxy進程

ps -ef|grep haproxy

3打開瀏覽器訪問

如果Mycat主備機均已啟動，則可以看到如下圖

4驗證負載均衡，通過HAProxy訪問Mycat

在HAProxy主機上執行(192.168.199.174HA的主機地址)

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

3 配置 Keepalived

1準備好Keepalived安裝包，傳到/opt目錄下

2解壓到/usr/local/src

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

3安裝依賴插件

yum install -y gcc openssl-devel popt-devel

4進入解壓后的目錄，進行配置，進行編譯

cd /usr/local/src/keepalived-1.4.2

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

5進行編譯，完成后進行安裝

make && make install

6運行前配置

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

#修改內容如下! 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 {

#主機配MASTER，備機配BACKUP

state MASTER

#所在機器網卡interfaceens33

virtual_router_id51#數值越大優先級越高

priority100advert_int1authentication {

auth_type PASS

auth_pass1111}

virtual_ipaddress {

#虛擬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(主機)

weight1rTCP_CHECK {

connect_timeout3retry3delay_before_retry3} }

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

weight1TCP_CHECK {

connect_timeout3nb_get_retry3delay_before_retry3}

} }

8、啟動Keepalived

同時啟動備機上的HA

service keepalived start

9、登錄驗證

mysql -umycat -p123456 -h 192.168.199.111 -P 48066

192.168.199.111 ：虛擬ip

此時是：

HA隱藏mycat的ip

KeepAlive隱藏HA的ip

4 測試高可用

1關閉mycat

2通過虛擬ip查詢數據

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)