Haproxy 实现负载均衡 

架构图

下载依赖 

yum -y install libnl libnl-devel
yum install gcc gcc-c++ openssl openssl-devel -y
yum update glib* -y

下载 haproxy

下载 haproxy，通过Index of /repo/pkgs/haproxy (fedoraproject.org)下载haproxy，进行解压 

tar -zxvf haproxy-2.0.3.tar.gz

进入解压后执行下面的编译命令

make TARGET=linux-glibc  PREFIX=/usr/app/haproxy-2.0.3
make install PREFIX=/usr/app/haproxy-2.0.3

配置环境变量，进入vim /etc/profile，写入配置

export HAPROXY_HOME=/usr/app/haproxy-2.0.3
export PATH=$PATH:$HAPROXY_HOME/sbin

  

使配置生效

source /etc/profile

修改haproxy.cfg

修改 node1 和 node2 的 haproxy.cfg，vim /etc/haproxy/haproxy.cfg

# 全局配置
global# 日志输出配置、所有日志都记录在本机，通过 local0 进行输出log 127.0.0.1 local0 info# 最大连接数maxconn 4096# 改变当前的工作目录chroot /usr/app/haproxy-2.0.3# 以指定的 UID 运行 haproxy 进程uid 99# 以指定的 GID 运行 haproxy 进程gid 99# 以守护进行的方式运行daemon# 当前进程的 pid 文件存放位置pidfile /usr/app/haproxy-2.0.3/haproxy.pid# 默认配置
defaults# 应用全局的日志配置log global# 使用4层代理模式，7层代理模式则为"http"mode tcp# 日志类别option tcplog# 不记录健康检查的日志信息option dontlognull# 3次失败则认为服务不可用retries 3# 每个进程可用的最大连接数maxconn 2000# 连接超时timeout connect 5s# 客户端超时timeout client 120s# 服务端超时timeout server 120s# 绑定配置
listen rabbitmq_adminbind :15673mode tcpbalance roundrobin rabbit-node为每个主机名server node1 rabbit-node1:15672server node2 rabbit-node2:15672server node3 rabbit-node3:15672# 绑定配置
listen rabbitmq_clusterbind :5673# 配置TCP模式mode tcp# 采用加权轮询的机制进行负载均衡balance roundrobin# RabbitMQ 集群节点配置 rabbit-node为每个主机名server node1 rabbit-node1:5672 check inter 5000 rise 2 fall 3 weight 1server node2 rabbit-node2:5672 check inter 5000 rise 2 fall 3 weight 1server node3 rabbit-node3:5672 check inter 5000 rise 2 fall 3 weight 1# 配置监控页面
listen monitorbind :8100mode httpoption httplogstats enablestats uri /statsstats refresh 5s

 点启动 haproxy

在两台节点启动 haproxy 

haproxy -f /etc/haproxy/haproxy.cfg
ps -ef | grep haproxy

开放端口 

firewall-cmd --add-port=8100/tcp --permanent
# 重启防火墙
firewall-cmd --reload

访问地址

http://192.168.2.3:8100/stats  

这样我们就可以通过192.168.2.3:5673或192.168.2.130:5673去访问rabbitmq

KeepAlived实现真正高可用

如果HAProxy 发生故障了怎么办，我们可以搭建 Keepalived 来解决 HAProxy 故障转移的问题 

下载KeepAlived

通过链接wget获取 

wget https://www.keepalived.org/software/keepalived-2.2.2.tar.gz

进行解压和编译

# 解压
tar -xvf keepalived-2.2.2.tar.gz# 编译安装
mkdir keepalived-2.2.2/build
cd keepalived-2.2.2/build
../configure --prefix=/usr/local/keepalived-2.2.2
make && make install

环境配置，配置文件链接 

# 创建目录
mkdir /etc/keepalived
# 备份
cp /usr/local/keepalived-2.2.2/etc/keepalived/keepalived.conf /usr/local/keepalived-2.2.2/etc/keepalived/keepalived.conf_bak
# 链接
ln -s /usr/local/keepalived-2.2.2/etc/keepalived/keepalived.conf /etc/keepalived/

将所有 Keepalived 脚本拷贝到 /etc/init.d/ 目录下

# 编译目录中的脚本
cp keepalived-2.2.2/keepalived/etc/init.d/keepalived /etc/init.d/
# 安装目录中的脚本
cp /usr/local/keepalived-2.2.2/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived-2.2.2/sbin/keepalived /usr/sbin/

设置开机自启动

chmod +x /etc/init.d/keepalived
chkconfig --add keepalived
systemctl enable keepalived.service

 配置 Keepalived

对 node1 主节点上 keepalived.conf 配置文件进行修改 ，vi /etc/keepalived/keepalived.conf

global_defs {# 路由id,主备节点不能相同router_id node1
}# 自定义监控脚本
vrrp_script chk_haproxy {# 脚本位置script "/etc/keepalived/haproxy_check.sh" # 脚本执行的时间间隔interval 5 weight 10
}vrrp_instance VI_1 {# Keepalived的角色，MASTER 表示主节点，BACKUP 表示备份节点state MASTER  # 指定监测的网卡，可以使用 ifconfig 进行查看interface ens33# 虚拟路由的id，主备节点需要设置为相同virtual_router_id 1# 优先级，主节点的优先级需要设置比备份节点高priority 100 # 设置主备之间的检查时间，单位为秒 advert_int 1 # 定义验证类型和密码authentication { auth_type PASSauth_pass 123456}# 调用上面自定义的监控脚本track_script {chk_haproxy}virtual_ipaddress {# 虚拟IP地址，可以设置多个192.168.2.200  }
}

node2的操作跟node1差不多，对node2 备份节点上,vi /etc/keepalived/keepalived.conf

global_defs {# 路由id,主备节点不能相同    router_id node2
}vrrp_script chk_haproxy {script "/etc/keepalived/haproxy_check.sh" interval 5 weight 10
}vrrp_instance VI_1 {# BACKUP 表示备份节点state BACKUP interface ens33virtual_router_id 1# 优先级，备份节点要比主节点低priority 50 advert_int 1 authentication { auth_type PASSauth_pass 123456}track_script {chk_haproxy}virtual_ipaddress {192.168.2.200  }
}

 编写HAProxy状态检测脚本

# 创建存放检测脚本的日志目录
mkdir -p /usr/local/keepalived-2.2.2/log# 创建检测脚本
vim /etc/keepalived/haproxy_check.sh

 脚本如下：

#!/bin/bashLOGFILE="/usr/local/keepalived-2.2.2/log/haproxy-check.log"
echo "[$(date)]：check_haproxy status" >> $LOGFILE# 判断haproxy是否已经启动
HAProxyStatusA=`ps -C haproxy --no-header|wc -l`
if [ $HAProxyStatusA -eq 0 ];thenecho "[$(date)]：启动haproxy服务......" >> $LOGFILE# 如果没有启动，则启动/usr/local/haproxy-2.3.10/sbin/haproxy -f /usr/local/haproxy-2.3.10/haproxy.cfg >> $LOGFILE 2>&1
fi# 睡眠5秒以便haproxy完全启动
sleep5# 如果haproxy还是没有启动，此时需要将本机的keepalived服务停掉，以便让VIP自动漂移到另外一台haproxy
HAProxyStatusB=`ps -C haproxy --no-header|wc -l`
if [ $HAProxyStatusB eq 0 ];thenecho "[$(date)]：haproxy启动失败，睡眼5秒后haproxy服务还是没有启动，现在关闭keepalived服务，以便让VIP自动漂移到另外一台haproxy" >> $LOGFILEsystemctl stop keepalived
fi

赋权

chmod +x /etc/keepalived/haproxy_check.sh

启动服务

分别在 node1 和 node2 上启动 KeepAlived 服务，命令如下 

systemctl start keepalived

查看虚拟 IP 

 ip a 命令查看到虚拟 IP 的情况

ip a

 访问rabbitmq

这样我们可以通过192.168.2.200:5672去访问rabbitmq

我们停掉node1的KeepAlived  

systemctl stop keepalived

 我们仍旧可以通过备份服务器去获取服务