案例一（haproxy+keepalived高可用负载均衡系统）【转】

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1.搭建环境描述：

  操作系统：

    [root@HA-1 ~]# cat /etc/redhat-release 

    CentOS release 6.7 (Final)

  地址规划：

  拓扑结构：

  此结构要实现的功能是：通过HAProxy实现三个站点的负载均衡，即当用户通过域名www.zb.com访问网站时，HAProxy要将请求发送到webapp1主机；当用户通过域名static.zb.com访问网站时，HAProxy要将请求发送到webapp2主机；当用户通过域名video.zb.com访问网站时，HAProxy要将请求发送到webapp3主机；当主HAProxyServer发送故障后，能立刻将负载均衡切换到备用HAProxyServer上。

  为了实现HAProxy的高可用功能，这里采用Keepalived作为高可用监控软件。

2.配置HAProxy负载均衡服务器

  关于HAProxy的安装，我这里使用yum安装的，就不做详细介绍。haproxy配置文件如下：

            global

                # to have these messages end up in /var/log/haproxy.log you will

                # need to:

                #

                # 1) configure syslog to accept network log events.  This is done

                #    by adding the ‘-r‘ option to the SYSLOGD_OPTIONS in

                #    /etc/sysconfig/syslog

                #

                # 2) configure local2 events to go to the /var/log/haproxy.log

                #   file. A line like the following can be added to

                #   /etc/sysconfig/syslog

                #

                #    local2.*                       /var/log/haproxy.log

                #

                log         127.0.0.1 local2

                pidfile     /var/run/haproxy.pid

                maxconn     4000

                user        haproxy

                group       haproxy

                daemon

                nbproc      1

                # turn on stats unix socket

            #---------------------------------------------------------------------

            # common defaults that all the ‘listen‘ and ‘backend‘ sections will

            # use if not designated in their block

            #---------------------------------------------------------------------

            defaults

                mode                    http

                retries                 3

                timeout connect         5s

                timeout client          30s

                timeout server          30s

                timeout check           2s

            listen admin_stats

                bind 0.0.0.0:19088

                mode http

                log 127.0.0.1 local0 err

                stats refresh 30s

                stats uri /haproxy-status

                stats realm welcome login\ Haproxy

                stats auth admin:admin

                stats hide-version

                stats admin if  TRUE

            #---------------------------------------------------------------------

            # main frontend which proxys to the backends

            #---------------------------------------------------------------------

            frontend www

                bind *:80

                mode http

                option httplog

                option forwardfor

                log global

                acl host_www hdr_dom(host) -i www.zb.com

                acl host_static hdr_dom(host) -i static.zb.com

                acl host_video hdr_dom(host) -i video.zb.com

                use_backend server_www if host_www

                use_backend server_static if host_static

                use_backend server_video if host_video

            #---------------------------------------------------------------------

            # static backend for serving up images, stylesheets and such

            #---------------------------------------------------------------------

            backend server_www

                mode http

                option redispatch

                option abortonclose

                balance roundrobin

                option httpchk GET /index.html

                server web01 10.0.0.150:80 weight 6 check inter 2000 rise 2 fall 3

            backend server_static

                mode http

                option redispatch

                option abortonclose

                balance roundrobin

                option httpchk GET /index.html

                server web02 10.0.0.151:80 weight 6 check inter 2000 rise 2 fall 3

            backend server_video

                mode http

                option redispatch

                option abortonclose

                balance roundrobin

                option httpchk GET /index.html

                server web03 10.0.0.152:80 weight 6 check inter 2000 rise 2 fall 3

  在这个HAProxy配置中，通过ACL规则将三个站点分别转向webapp1、webapp2和webapp3三个服务节点上，这样变相地实现了负载均衡。三个后端实例server_www、server_static和server_video虽然只有一台服务器，但是如果站点访问量增加，可以很容易地增加后端服务器，实现真正的负载均衡。

  将haproxy.conf文件复制到备用的haproxy-backup服务器上，然后在主、备HAProxy上依次启动HAProxy服务。

3.配置主、备Keepalived服务器

  依次在主、备两个节点上安装Keepalived。我这还是用yum安装，在haproxy-server主机上，keepalived.conf的内容如下：  

            ! Configuration File for keepalived

            global_defs {

               notification_email {

                 acassen@firewall.loc

                 failover@firewall.loc

                 sysadmin@firewall.loc

               }

               notification_email_from Alexandre.Cassen@firewall.loc

               smtp_server 192.168.200.1

               smtp_connect_timeout 30

               router_id LVS_DEVEL

            }

            vrrp_script check_haproxy {

               script "killall -0 haproxy"

               interval 2

            }

            vrrp_instance HAProxy_HA {

               state BACKUP

               interface eth0

               virtual_router_id 80

               priority 100

               advert_int 2

               nopreempt

               authentication {

                  auth_type PASS

                  auth_pass aaaa

               }

               notify_master "/etc/keepalived/mail_notify.sh master"

               notify_backup "/etc/keepalived/mail_notify.sh backup"

               notify_fault "/etc/keepalived/mail_notify.sh fault"

               track_script {

                  check_haproxy

               }

               virtual_ipaddress {

                  10.0.0.40/24 dev eth0

               }

            }

  其中，/etc/keepalived/mail_notify.sh文件是一个邮件通知程序，当keepalived进行Master、Backup、Fault状态切换时，将会发送通知邮件给运维人员，这样可以及时了解高可用集群的运行状态，以便在适当的时候人为介入处理故障。mail_notify.sh文件的内容如下：

        #!/bin/bash

        #监控keepalived切换状态脚本

        IP=`ifconfig | grep 10.0.0|awk ‘{print $2}‘|awk -F ‘:‘ ‘{print $2}‘`

        echo "${IP} $1 状态被激活，请确认HAProxy服务运行状态！"|mail -s "HAProyx状态切换报警" 11*******11@qq.com

  最后，将keepalived.conf文件和mail_notify.sh文件复制到haproxy-backup服务器上对应的位置，然后将keepalived文件中priority值修改为90，由于配置的是不抢占模式，因此，还需要在backup-haproxy服务器上去掉nopreempt选项。

  完成所有配置后，分别在haproxy-server和haproxy-backup主机上依次启动HAProxy服务和Keepalived服务。注意，这里一定要先启动HAProxy服务，因为Keepalived服务在启动的时候回自动检测HAProxy服务是否正常，如果发现HAProxy服务没有启动，那么主、备Keepalived将自动进入Fault状态。在依次启动服务后，在正常情况下VIP地址应该运行在haproxy-server服务器上，通过命令“ip a”可以查看VIP是否已经正常加载。

4.测试HAProxy+Keepalived高可用负载均衡集群

  高可用的HAProxy负载均衡系统能够实现HAProxy的高可用性、负载均衡特性和故障切换特性。

  测试keepalived的高可用功能：

    高可用性是通过HAProxy的两个HAProxy Server完成的。为了模拟故障，先将主haproxy-server上面的HAProxy服务停止，接着观察haproxy-server上的keepalived的运行日志，信息如下：

                Jul 24 16:04:13 data-1-1 Keepalived_vrrp[25735]: VRRP_Script(check_haproxy) failed

                Jul 24 16:04:14 data-1-1 Keepalived_vrrp[25735]: VRRP_Instance(HAProxy_HA) Received higher prio advert

                Jul 24 16:04:14 data-1-1 Keepalived_vrrp[25735]: VRRP_Instance(HAProxy_HA) Entering BACKUP STATE

                Jul 24 16:04:14 data-1-1 Keepalived_vrrp[25735]: VRRP_Instance(HAProxy_HA) removing protocol VIPs.

                Jul 24 16:04:14 data-1-1 Keepalived_healthcheckers[25734]: Netlink reflector reports IP 10.0.0.40 removed

    这段日志显示了check_haproxy检测失败后，haproxy-server自动进入了backup状态，同时释放了虚拟IP。由于执行了角色切换，此时mail_notify.sh脚本应该会自动执行并发送状态切换邮件。

    然后观察备机haproxy-backup上Keepalived的运行日志，信息如下：

                Jul 24 16:04:14 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) forcing a new MASTER election

                Jul 24 16:04:14 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) forcing a new MASTER election

                Jul 24 16:04:16 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) Transition to MASTER STATE

                Jul 24 16:04:18 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) Entering MASTER STATE

                Jul 24 16:04:18 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) setting protocol VIPs.

                Jul 24 16:04:18 data-1-2 Keepalived_healthcheckers[25242]: Netlink reflector reports IP 10.0.0.40 added

                Jul 24 16:04:18 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) Sending gratuitous ARPs on eth0 for 10.0.0.40

                Jul 24 16:04:23 data-1-2 Keepalived_vrrp[25243]: VRRP_Instance(HAProxy_HA) Sending gratuitous ARPs on eth0 for 10.0.0.40

    从日志中可以看出，主机出现故障后，haproxy-backup立刻检测到，此时，haproxy-backup变成Master角色，并且接管了主机的虚拟IP资源，最后将虚拟IP绑定在eth0设备上。

    接着，重新启动主haproxy-server上的haproxy服务，然后观察haproxy-server上的日志状态：

                Jul 24 18:22:16 data-1-1 Keepalived_vrrp[30896]: VRRP_Script(check_haproxy) succeeded

                Jul 24 18:22:17 data-1-1 Keepalived_vrrp[30896]: VRRP_Instance(HAProxy_HA) Entering BACKUP STATE

   从日志输出可知，在HAProxy服务启动后，Keepalived监控程序vrrp_script检测到HAProxy已经正常运行，但是并没有执行切换操作，这是由于Keepalived集群中设置了不抢占模式的缘故。

 测试负载均衡功能：

    将www.zb.com、static.zb.com、video.zb.com这个三个域名解析到10.0.0.40这个虚拟IP上，然后依次访问网站，如果HAProxy运行正常，并且ACL规则设置正确，这里三个网站应该都能正常访问，如果出现错误，可通过查看HAProxy的运行日志判断哪里出现问题。

转自

案例一（haproxy+keepalived高可用负载均衡系统）-闫利朋的博客-51CTO博客
http://blog.51cto.com/6284444/2149581

案例一（haproxy+keepalived高可用负载均衡系统）【转】

标签：--   email   des   mode   reflector   mod   显示   nbsp   stat   

原文地址：https://www.cnblogs.com/paul8339/p/9649141.html