mycat+haproxy+keepalived搭建高可用负载均衡mysql集群

keepalived-2.0.5
haproxy-1.8.12
Mycat-server-1.6.5

主机1：ip192.168.1.165 安装keepalived、haproxy、Mycat
主机2：ip192.168.1.111 安装keepalived、haproxy、Mycat
vip:192.168.1.180
keepalived与haproxy需安装在同一台机器上

运作理解：主机1与主机2上的keepalived会为该服务器抢占vip，抢占到vip后，对该主机的访问可以通过原来的ip（ip192.168.1.165或者192.168.1.111）访问，也可以直接通过vip（192.168.1.180）访问，当其中一台宕机时，vip会漂移到另一台机器上，当我们访问192.168.1.180时haproxy会根据配置将请求分发到两台Mycat上实现负载均衡，并且haproxy会检测mycat是否存活。

一、haproxy安装

1、安装haproxy

国内镜像地址：http://pkgs.fedoraproject.org/repo/pkgs/haproxy/
查看内核版本

uname -r

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根据内核版本选择编译参数：

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这里内核是3.10的选择 linux2628，安装haproxy

useradd -r haproxy
wget https://src.fedoraproject.org/repo/pkgs/haproxy/haproxy-1.8.12.tar.gz/sha512/2b782a54988cc88d1af0e5f011af062910e8fac28eab13db7e05a58d0d23961f827da47e3871e8d081f5a2d222588480d81dec2e9f14ec9f54a1c3cb5bf3d56a/haproxy-1.8.12.tar.gz
tar -zxvf haproxy-1.8.12.tar.gz
cd  haproxy-1.8.12
make TARGET=linux2628 PREFIX=/usr/local/haproxy
make install PREFIX=/usr/local/haproxy
cd /usr/local/haproxy
chown -R haproxy.haproxy *

安装成功后，查看版本

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2、配置haproxy

cd /usr/local/haproxy
touch haproxy.cfg

vim /usr/local/haproxy/haproxy.cfg
写入一下内容：

global
#设置日志
    log 127.0.0.1   local0
    chroot /usr/local/haproxy
#用户与用户组
    user haproxy
    group haproxy
#定义每个haproxy进程的最大连接数 ，由于每个连接包括一个客户端和一个服务器端，所以单个进程的TCP会话最大数目将是该值的两倍。
    maxconn 4096
# 以守护进程的方式运行
    daemon
defaults
log global
#日志中不记录空连接
option dontlognull
# 定义连接后端服务器的失败重连次数，连接失败次数超过此值后将会将对应后端服务器标记为不可用
retries 3
option redispatch
# 设置成功连接到一台服务器的最长等待时间，默认单位是毫秒
timeout connect 5000
# 设置连接客户端发送数据时的成功连接最长等待时间，默认单位是毫秒
timeout client 50000
# 设置服务器端回应客户度数据发送的最长等待时间，默认单位是毫秒
timeout server 50000
#统计页面
listen  admin_stats
        bind 192.168.1.180:48800  
        mode http
#采用http日志格式  
        option httplog
#统计页面自动刷新时间  
        stats refresh 30s
#统计页面url
        stats uri /admin_stats
#统计页面密码框上提示文本
        stats realm Haproxy Manager
#统计页面用户名和密码设置    
        stats auth admin:admin
#隐藏统计页面上HAProxy的版本信息
        stats hide-version
listen mycat_service
# 绑定192.168.1.180:8067端口访问mycat8066端口
bind 192.168.1.180:8067
# 定义为tcp模式
      mode tcp
#采用http日志格式
      option tcplog
# 开启对后端服务器的健康检测
  option httpchk OPTIONS * HTTP/1.1\r\nHost:\ www
# 设置haproxy的调度算法
      balance roundrobin
#根据调度分配到真实的后台地址，参数解释：port 48700:检测端口48700， inter 5s:5秒检测一次，rise 2:检测成功2次表示服务器可用，fall 3:检测失败3次后表示服务器不可用
  server mycat_111 192.168.1.111:8066 check port 48700 inter 5s rise 2 fall 3
  server mycat_165 192.168.1.165:8066 check port 48700 inter 5s rise 2 fall 3
#设置服务器端回应客户度数据发送的最长等待时间，默认单位是毫秒
 timeout server 20000
listen mycat_admin
#绑定192.168.1.180:9067端口访问mycat9066端口
bind  192.168.1.180:9067
mode tcp
option tcplog
option httpchk OPTIONS * HTTP/1.1\r\nHost:\ www
balance roundrobin
server mycat_111 192.168.1.111:9066 cookie 1 check port 48700 inter 5s rise 2 fall 3
server mycat_165 192.168.1.165:9066 cookie 2 check port 48700 inter 5s rise 2 fall 3
timeout server 20000

启动和停止haproxy命令

/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.cfg #启动
killall haproxy #停止

3、配置haproxy记录日志功能

默认haproxy是不记录日志的，为了记录日志还需要配置syslog模块，在linux下是rsyslogd服务，需要先安装rsyslog

yum –y install rsyslog
mkdir /etc/rsyslog.d
cd /etc/rsyslog.d/
touch haproxy.conf

vim haproxy.conf
写入一下内容

$ModLoad imudp
$UDPServerRun 514
local0.* /var/log/haproxy.log

vim /etc/rsyslog.conf
修改两处：1在#### RULES ####上面一行加入以下内容

# Include all config files in /etc/rsyslog.d/
$IncludeConfig /etc/rsyslog.d/*.conf

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第二处在local7.* /var/log/boot.log下面增加

local0.*                                                /var/log/haproxy.log

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重启rsyslog服务

systemctl restart rsyslog.service

将rsyslog加入自动启动服务

systemctl enable rsyslog.service

二、配置监听mycat是否存活

在Mycat server1 Mycat server2上都需要添加检测端口48700的脚本，为此需要用到xinetd，xinetd为linux系统的基础服务，在xinetd目录下面增加脚本与端口的映射配置文件。

yum install xinetd -y
cd /etc/xinetd.d
touch mycat_status

vim /etc/xinetd.d/mycat_status
写入以下内容

service mycat_status
{
flags = REUSE
socket_type = stream
port = 48700
wait = no
user = nobody
server =/usr/local/bin/mycat_status
log_on_failure += USERID
disable = no
}

创建xinetd启动服务脚本
vim /usr/local/bin/mycat_status

#!/bin/bash
#/usr/local/bin/mycat_status.sh
# This script checks if a mycat server is healthy running on localhost. It will
# return:
#
# "HTTP/1.x 200 OK\r" (if mycat is running smoothly)
#
# "HTTP/1.x 503 Internal Server Error\r" (else)
mycat=`/usr/local/mycat/bin/mycat status |grep 'not running'| wc -l`
if [ "$mycat" = "0" ];
then
/bin/echo -e "HTTP/1.1 200 OK\r\n"
else
/bin/echo -e "HTTP/1.1 503 Service Unavailable\r\n"
fi

修改脚本文件权限

chmod 777 /usr/local/bin/mycat_status
chmod 777 /etc/xinetd.d/mycat_status

将启动脚本加入服务
vim /etc/services
在末尾加入

mycat_status    48700/tcp               # mycat_status

重启xinetd服务

systemctl restart xinetd.service

验证mycat_status服务是否启动成功

netstat -antup|grep 48700

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注意：/etc/xinetd.d/mycat_status里的service mycat_status(服务名)和port = 48700(端口)要与 /etc/services里的相同

三、keepalived安装

1、安装依赖

yum install -y openssl-devel openssl libnl libnl-devel libnfnetlink-devel

2、keepalived安装

wget http://www.keepalived.org/software/keepalived-2.0.5.tar.gz
tar -zxvf keepalived-2.0.5.tar.gz
cd keepalived-2.0.5
./configure --prefix=/usr/local/keepalived
make
make install
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp ./keepalived/etc/init.d/keepalived /etc/init.d/
mkdir /etc/keepalived
cd /etc/keepalived/
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived
mkdir -p  /usr/local/keepalived/var/log

2、keepalived配置

a、查看网卡

ifconfig

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我这里网卡是enp0s3所以配置里的interface为enp0s3，主机1与主机2配置基本一样，state与priority 不同。b、配置主机2的keepalived
vim /etc/keepalived/keepalived.conf

! Configuration Fileforkeepalived
#VRRP脚本
vrrp_script chk_http_port {
#执行的脚本
script"/etc/keepalived/scripts/check_haproxy.sh"
 #脚本执行间隔
interval 2
#脚本结果导致的优先级变更：2表示优先级+10；-2则表示优先级-2
weight 2
}
#vrrp实例
vrrp_instance VI_1 {
state BACKUP
#本机网卡
interface enp0s3
##VRRP组名，两个节点的设置必须一样，以指明各个节点属于同一VRRP组
virtual_router_id 51
#优先级，数值愈大，优先级越高
priority 120
#检查间隔，默认1秒
advert_int 1
#设置认证
authentication {
#认证方式
auth_type PASS
#认证密码
auth_pass 1111
}
track_script {
#调用脚本check_haproxy.sh检查haproxy是否存活
chk_http_port
}
#虚拟IP地址池，可以有多个IP，每个IP占一行
virtual_ipaddress {
192.168.1.180 dev enp0s3 scope global
}
#指定当切换到master时，执行的脚本
notify_master /etc/keepalived/scripts/haproxy_master.sh
#指定当切换到backup时，执行的脚本
notify_backup /etc/keepalived/scripts/haproxy_backup.sh
#故障时执行的脚本
notify_fault /etc/keepalived/scripts/haproxy_fault.sh
notify_stop /etc/keepalived/scripts/haproxy_stop.sh

c、配置主机1的keepalived

! Configuration Fileforkeepalived
vrrp_script chk_http_port {
script"/etc/keepalived/scripts/check_haproxy.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface enp0s3
virtual_router_id 51
priority 150
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
track_script {
chk_http_port
}
virtual_ipaddress {
192.168.1.180 dev enp0s3 scope global
}
notify_master /etc/keepalived/scripts/haproxy_master.sh
notify_backup /etc/keepalived/scripts/haproxy_backup.sh
notify_fault /etc/keepalived/scripts/haproxy_fault.sh
notify_stop /etc/keepalived/scripts/haproxy_stop.sh
}

3、创建配置文件和脚本

mkdir /etc/keepalived/scripts

a、创建检查haproxy是否存活的脚本
vim /etc/keepalived/scripts/check_haproxy.sh

#!/bin/bash
STARTHAPROXY="/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.cfg"
STOPKEEPALIVED="/etc/init.d/keepalived stop"
LOGFILE="/usr/local/keepalived/var/log/keepalived-haproxy-state.log"
echo "[check_haproxy status]" >> $LOGFILE
A=`ps -C haproxy --no-header |wc -l`
echo "[check_haproxy status]" >> $LOGFILE
date >> $LOGFILE
#如果没有haproxy进程存在，就启动haproxy，停止keepalived，并写入日志
if [ $A -eq 0 ];then
echo $STARTHAPROXY >> $LOGFILE
$STARTHAPROXY >> $LOGFILE 2>&1
sleep 5
fi
if [ `ps -C haproxy --no-header |wc -l` -eq 0 ];then
exit 0
else
exit 1
fi

b、创建切换到MASTER与BACKUP脚本
vim /etc/keepalived/scripts/haproxy_master.sh
vim /etc/keepalived/scripts/haproxy_backup.sh
在两个文件中写入以下内容

#!/bin/bash
STARTHAPROXY=`/usr/local/haproxy/sbin/haproxy -f /usr/local/haproxy/haproxy.cfg`
STOPHAPROXY=`ps -ef | grep sbin/haproxy | grep -v grep | awk '{print $2}'| xargs kill -s 9`
LOGFILE="/usr/local/keepalived/var/log/keepalived-haproxy-state.log"
echo "[master]" >> $LOGFILE
date >> $LOGFILE
echo "Being master...." >> $LOGFILE 2>&1
echo "stop haproxy...." >> $LOGFILE 2>&1
$STOPHAPROXY >> $LOGFILE 2>&1
echo "start haproxy...." >> $LOGFILE 2>&1
$STARTHAPROXY >> $LOGFILE 2>&1
echo "haproxy stared ..." >> $LOGFILE

c、创建故障时执行的脚本
vim /etc/keepalived/scripts/haproxy_fault.sh

#!/bin/bash
LOGFILE=/usr/local/keepalived/var/log/keepalived-haproxy-state.log
echo "[fault]" >> $LOGFILE
date >> $LOGFILE

d、创建停止vrrp脚本
vim /etc/keepalived/scripts/haproxy_stop.sh

#!/bin/bash
LOGFILE=/usr/local/keepalived/var/log/keepalived-haproxy-state.log
echo "[stop]" >> $LOGFILE
date >> $LOGFILE

4、赋予脚本可执行权限

chmod 777 /etc/keepalived/scripts/*

5、启动keepalived

systemctl start keepalived.service

6、加入开机启动

systemctl enable keepalived.service

四、测试

在浏览器输入http://192.168.1.180:48800/admin_stats

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查看8067与9067端口是否在监听

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连接8067端口
mysql -uroot -p123456 -h192.168.1.180 -P806

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可以连接，到此就搭建完成了