HAProxy+Keepalived高可用负载均衡
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一 基础准备
1.1 部署环境及说明
系统OS：CentOS 6.8 64位
HAProxy软件：HA-Proxy version 1.5.18
Keepalived软件：keepalived-1.3.6.tar.gz
官方链接：http://www.haproxy.org/ （国内可能无法打开）
下载连接：http://pkgs.fedoraproject.org/repo/pkgs/haproxy/
部署说明：当用户访问对应的域名时，HAProxy能将请求发送到对应的后端主机上，同时当主HAProxy服务器发生故障后，能立刻将负载均衡服务切换到备用HAProxy服务器上。
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主机名
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主机IP地址
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集群角色
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虚机IP/域名
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master
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172.24.8.10
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主HAProxy服务器
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172.24.8.100
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backup
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172.24.8.11
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备HAProxy服务器
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webapp1
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172.24.8.30
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后端web服务器
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www.lz.com
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webapp2
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172.24.8.31
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static.lz.com
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webapp3
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172.24.8.32
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video.lz.com
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1.2 架构规划
二 后端httpd集群部署
2.1 部署httpd集群
1 [[email protected] ~]# yum -y install httpd 2 [[email protected] ~]# vi /var/www/html/index.html 3 This is my www.lz.com! 4 [[email protected] ~]# vi /var/www/html/index.html 5 This is my static.lz.com! 6 [[email protected] ~]# vi /var/www/html/index.html 7 This is my video.lz.com! 8 [[email protected] ~]# systemctl start httpd.service 9 [[email protected] ~]# systemctl enable httpd.service 10 [[email protected] ~]# systemctl stop firewalld.service 11 [[email protected] ~]# systemctl disable firewalld.service 12 [[email protected] ~]# vi /etc/selinux/config 13 SELINUX=disabled 14 [[email protected] ~]# setenforce 0 #关闭SELinux及防火墙
注意：后端real server节点都需要安装，本环境针对httpd简单安装即可，无需过多配置。
三 基础NTP部署
3.1 NTP部署
1 [[email protected] ~]# yum -y install ntp 2 [[email protected] ~]# systemctl start ntpd.service
建议：替换附件中的ntp配置文件，建议采用阿里云时钟进行同步。
注意：为了保证集群的稳定性，强烈建议在所有节点均部署NTP同步服务，保证所有时钟一致。
四 Keepalived部署
4.1 编译环境
安装基础环境及依赖：
1 # yum -y install gcc gcc-c++ make kernel-devel kernel-tools kernel-tools-libs kernel libnl libnl-devel libnfnetlink-devel openssl-devel wget openssh-clients
4.2 安装Keepalived
1 [[email protected]_master ~]# wget http://www.keepalived.org/software/keepalived-1.3.6.tar.gz 2 [[email protected]_master ~]# tar -zxvf keepalived-1.3.6.tar.gz 3 [[email protected]_master ~]# cd keepalived-1.3.6/ 4 [[email protected] keepalived-1.3.6]# ./configure --prefix=/usr/local/keepalived 5 [[email protected]_master keepalived-1.3.6]# make && make install
注意：CentOS6.8安装高于1.3.6版本会出现未知错误。
4.3 添加Keepalived启动相关服务
1 [[email protected]_master ~]# mkdir /etc/keepalived 2 [[email protected]_master ~]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ 3 [[email protected]_master ~]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ 4 [[email protected]_master ~]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/ 5 [[email protected]_master ~]# vi /etc/init.d/keepalived #创建Keepalived启动脚本，见附件 6 [[email protected]_master ~]# chmod u+x /etc/rc.d/init.d/keepalived
4.4 配置Keepalived
1 [[email protected]_master ~]# vi /etc/keepalived/keepalived.conf 2 global_defs { 3 notification_email { 4 #…… 5 } 6 notification_email_from [email protected] 7 smtp_server 192.168.200.1 8 smtp_connect_timeout 30 9 router_id LVS_DEVEL 10 } 11 12 vrrp_script check_haproxy { 13 script "/usr/bin/killall -0 haproxy" 14 interval 2 15 weight 21 16 } 17 18 vrrp_instance HAProxy_HA { 19 state BACKUP #在HAProxy主备均设置为BACKUP 20 interface eth0 21 virtual_router_id 80 22 priority 100 23 advert_int 2 24 nopreempt #不抢占模式 25 authentication { 26 auth_type PASS 27 auth_pass 1111 28 } 29 30 notify_master "/etc/keepalived/master.sh" 31 notify_backup "/etc/keepalived/backup.sh" 32 notify_fault "/etc/keepalived/fault.sh" 33 34 track_script { 35 check_haproxy 36 } 37 38 virtual_ipaddress { 39 172.24.8.100 dev eth0 40 } 41 }
4.5 编写Keepalived脚本
1 [[email protected]_master ~]# vi /etc/keepalived/master.sh 2 #!/bin/bash 3 LOGFILE=/var/log/keepalived-mysql-state/log 4 date >>$LOGFILE 5 echo "[Master]" >>$LOGFILE 6 [[email protected]_master ~]# vi /etc/keepalived/backup.sh 7 #!/bin/bash 8 LOGFILE=/var/log/keepalived-mysql-state/log 9 date >>$LOGFILE 10 echo "[BACKUP]" >>$LOGFILE 11 [[email protected]_master ~]# vi /etc/keepalived/fault.sh 12 #!/bin/bash 13 LOGFILE=/var/log/keepalived-mysql-state/log 14 date >>$LOGFILE 15 echo "[FAULT]" >>$LOGFILE 16 [[email protected]_master ~]# chmod u+x /etc/keepalived/backup.sh 17 [[email protected]_master ~]# chmod u+x /etc/keepalived/master.sh 18 [[email protected]_master ~]# chmod u+x /etc/keepalived/fault.sh
提示：本环境采用测试脚本，真实环境建议采用自动发送邮件通知运维员的脚本。
4.5 Bakcup节点配置
1 [[email protected]_master ~]# scp /etc/keepalived/keepalived.conf 172.24.8.11:/etc/keepalived/keepalived.conf #将配置好的Master节点的配置文件复制到Backup节点 2 [[email protected]_slave ~]# vi /etc/keepalived/keepalived.conf 3 state BACKUP 4 priority 80
注意：在HAProxy备节点也设置为BACKUP，priority修改为低于HAProxy主角色的优先级即可，同时去掉nopreempt。
1 [[email protected]_master ~]# scp /etc/keepalived/*.sh 172.24.8.11:/etc/keepalived/ 2 #将对应的脚本也复制至backup节点。
五 HAProxy部署
5.1 HAProxy安装
1 [[email protected]_master ~]# yum -y install haproxy
提示：需要在主备HAProxy节点都安装。
5.2 HAProxy配置
1 [[email protected]_master ~]# vi /etc/haproxy/haproxy.cfg 2 global 3 log 127.0.0.1 local0 info 4 chroot /var/lib/haproxy 5 pidfile /var/run/haproxy.pid 6 maxconn 4096 7 user haproxy 8 group haproxy 9 daemon 10 nbproc 1 11 defaults 12 mode http 13 log global 14 retries 3 15 timeout connect 5s 16 timeout client 30s 17 timeout server 30s 18 timeout check 2s 19 frontend www 20 bind 172.24.8.100:80 21 mode http 22 option httplog 23 option forwardfor 24 log global 25 26 acl host_www hdr_dom(host) -i www.lz.com #配置不同域名分发不同后端策略 27 acl host_static hdr_dom(host) -i static.lz.com 28 acl host_video hdr_dom(host) -i video.lz.com 29 30 use_backend server_www if host_www #配置不同域名分发不同后端策略 31 use_backend server_static if host_static 32 use_backend server_video if host_video 33 backend server_www #后端真是服务器 34 mode http 35 option redispatch 36 option abortonclose 37 balance roundrobin 38 option httpchk GET /index.html 39 server webapp1 172.24.8.30:80 weight 6 check inter 2000 rise 2 fall 3 40 backend server_static #后端真是服务器 41 mode http 42 option redispatch 43 option abortonclose 44 balance roundrobin 45 option httpchk GET /index.html 46 server webapp2 172.24.8.31:80 weight 6 check inter 2000 rise 2 fall 3 47 backend server_video #后端真是服务器 48 mode http 49 option redispatch 50 option abortonclose 51 balance roundrobin 52 option httpchk GET /index.html 53 server webapp3 172.24.8.32:80 weight 6 check inter 2000 rise 2 fall 3 54 [[email protected]_master ~]# scp /etc/haproxy/haproxy.cfg [email protected]:/etc/haproxy/haproxy.cfg #将配置文件复制至HAProxy备节点
5.3 打开转发
1 [[email protected]_master ~]# vi /etc/sysctl.conf 2 net.ipv4.ip_nonlocal_bind = 1 3 [[email protected]_master ~]# sysctl -p
注意：绑定非本机的IP必须在sysctl.conf文件中配置。
六 启动服务
1 [[email protected] ~]# systemctl start httpd
提示：三个节点的httpd服务均启动。
1 [[email protected]_master ~]# service haproxy start
提示：必须先启动HAProxy服务，之后启动Keepalived，因为Keepalived会先检测HAProxy服务进程。
1 [[email protected]_master ~]# service keepalived start
七 验证测试
7.1 高可用验证
1 [[email protected]_master ~]# ip add
1 [[email protected]_master ~]# service haproxy stop #停止HAProxy主节点的HAProxy进程 2 [[email protected]_master ~]# tail -f /var/log/messages #观察HAProxy主节点日志
1 [[email protected]_slave ~]# ip addr #查看备HAProxy节点的IP
结论：通过测试可知当主HAProxy节点服务异常，Keepalived会检测到，同时HAProxy会将vip从主节点移除，备HAProxy会接管。
1 [[email protected]_master ~]# service haproxy start
结论：由于配置了非抢占模式，主HAProxy恢复进程之后，依旧由备HAProxy提供服务，vip不会切回至主HAProxy。
7.2 负载均衡测试
主机hosts中添加如下解析：
1 172.24.8.100 www.lz.com 2 172.24.8.100 static.lz.com 3 172.24.8.100 video.lz.com
浏览器分别访问不用的三个域名：
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