linux学习之使用keepalived+haproxy搭建高可用服务器

环境如下：
192.168.2.199
vm1.example.com HA主服务器
192.168.2.202
vm2.example.com HA备服务器
192.168.2.205
vm3.example.com 
192.168.2.175
vm4.example.com
其中1和2做HA，3和4做httpd的lvs。虚拟IP为192.168.2.213

1、使用keepalixed+haproxy负载均衡 

lvs 适合应用层负载均衡，nginx  haproxy适合做网站的负载均衡,haproxy 吞吐量比较高，一般和lvs结合:user->vip+proxy->realserver

[root@vm1 ~]# /etc/init.d/keepalived stop 关闭1和2的keepalived

lftp i:~> get pub/docs/haproxy/haproxy-1.4.24.tar.gz 

[root@vm1 ~]# yum install rpm-build pcre-devel -y

[root@vm1 ~]# rpmbuild -tb haproxy-1.4.24.tar.gz 

[root@vm1 ~]# rpm -ivh /root/rpmbuild/RPMS/x86_64/haproxy-1.4.24-1.x86_64.rpm

[root@vm1 ~]# mkdir /usr/share/haproxy

[root@vm1 ~]# vim /etc/haproxy/haproxy.cfg 

        option  redispatch 更改

        stats uri /status 添加

listen  www.haproxy.com *:80

        balance roundrobin

        server  web1 192.168.2.205:80 cookie app1inst1 check inter 2000 rise 2 fall 3

        server  web2 192.168.2.175:80 cookie app1inst2 check inter 2000 rise 2 fall 3

之后的全部删除。

[root@vm1 ~]# /etc/init.d/haproxy start

在真机中写入解析，192.168.2.199 www.haproxy.com

2、打开日志记录

[root@vm1 ~]# vim /etc/haproxy/haproxy.cfg 

global

        log 127.0.0.1   local0 指定日志设备

        #log 127.0.0.1  local1 notice

        log 127.0.0.1   local0 info 指定日志类型

        maxconn 4096

        chroot /usr/share/haproxy

        uid 99

        gid 99

        daemon

        #debug

        #quiet

defaults

        log     global

        mode    http

        option  httplog

        option  dontlognull

        retries 3

        option  redispatch

        maxconn 2000

        contimeout      5000

        clitimeout      50000

        srvtimeout      50000

        #stats uri /status

listen  www.haproxy.com *:80 这里真机访问测试的话，做vm1的解析

        balance roundrobin

        server  web1 192.168.2.205:80 cookie app1inst1 check inter 2000 rise 2 fall 3 #2秒检测，成功判定2次，失败判定3次

        server  web2 192.168.2.175:80 cookie app1inst2 check inter 2000 rise 2 fall 3

listen status *:8080

        stats enable

        stats uri /status

        stats auth admin:mmmmmm 认证

        stats refresh 5s 刷新时间

[root@vm1 ~]# vim /etc/rsyslog.conf 添加

$ModLoad imudp

$UDPServerRun 514

#### RULES ####

local0.*                                                /var/log/haproxy.log

[root@vm1 ~]# /etc/init.d/rsyslog restart

[root@vm1 ~]# /etc/init.d/haproxy restart

[root@vm1 ~]# cat /var/log/haproxy.log 

浏览器访问http://192.168.2.199:8080/status

3、结合keepalived高可用和haproxy负载均衡

[root@vm1 ~]# vim /etc/keepalived/keepalived.conf 主结点配置

! Configuration File for keepalived

vrrp_script check_haproxy {

   script "/etc/keepalived/check_haproxy"

   interval 2 检测脚本运行频率

   weight 2

}

global_defs {

   notification_email {

     root@localhost

   }

   notification_email_from keepalived@vm1.example.com

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id LVS_DEVEL

}

vrrp_instance VI_1 {

    state MASTER

    interface eth0

    virtual_router_id 94

    priority 100

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        192.168.2.213

    }

    track_script {

        check_haproxy

    }

}

脚本的编写

[root@vm1 ~]# vim /etc/keepalived/check_haproxy

#!/bin/bash

/etc/init.d/haproxy status &> /dev/null || /etc/init.d/haproxy restart &> /dev/null

if [ $? -ne 0 ];then

/etc/init.d/keepalived stop &> /dev/null

fi

[root@vm1 ~]# chmod +x /etc/keepalived/check_haproxy 

[root@vm1 ~]# scp /etc/keepalived/check_haproxy vm2.example.com:/etc/keepalived/

[root@vm1 ~]# scp rpmbuild/RPMS/x86_64/haproxy-1.4.24-1.x86_64.rpm vm2.example.com:

修改备结点的配置文件

[root@vm2 ~]# vim /etc/keepalived/keepalived.conf 

! Configuration File for keepalived

vrrp_script check_haproxy {

   script "/etc/keepalived/check_haproxy"

   interval 2

   weight 2

}

global_defs {

   notification_email {

     root@localhost

   }

   notification_email_from keepalived@vm2.example.com

   smtp_server 127.0.0.1

   smtp_connect_timeout 30

   router_id LVS_DEVEL

}

vrrp_instance VI_1 {

    state BACKUP

    interface eth0 

    virtual_router_id 94

    priority 50

    advert_int 1

    authentication {

        auth_type PASS

        auth_pass 1111

    }

    virtual_ipaddress {

        192.168.2.213

    }

    track_script {

        check_haproxy

    }

}

备结点安装haproxy

[root@vm2 ~]# rpm -ivh haproxy-1.4.24-1.x86_64.rpm 

[root@vm2 ~]# mkdir /usr/share/haproxy

[root@vm1 ~]# scp /etc/haproxy/haproxy.cfg vm2.example.com:/etc/haproxy/ 发送配置文件

[root@vm2 ~]# vim /etc/rsyslog.conf 

$ModLoad imudp

$UDPServerRun 514

#### RULES ####

local0.*                                                /var/log/haproxy.log

[root@vm2 ~]# /etc/init.d/rsyslog restart

启动服务测试

[root@vm1 ~]# /etc/init.d/keepalived start

[root@vm2 ~]# /etc/init.d/keepalived start

这时，在主结点上和备结点就可以看到haproxy启动，主结点拥有虚拟IP：213，使用ip addr show查看，同时查看日志tail -f /var/log/messages

访问192.168.2.213就可以轮寻，这时关闭1的keepalived，2就成为主结点，拥有IP，不影响访问。再次开启1的keepalived会回切回去。

即keep每隔2s检测ha状态，没启动则重启，重启不了就关闭keep，让他跳到备结点。所谓的虚拟ip是跟着haproxy正常的主机的，因此保证了高可用。

最后自己做遗留得问题是：虚拟ip可以添加，但是只有自己可以用w3m访问，真机访问不了，也ping不同。

日志如下

Jun 11 11:31:17 ha1 Keepalived_vrrp[9217]: VRRP_Instance(VI_1) setting protocol VIPs.

Jun 11 11:31:17 ha1 Keepalived_vrrp[9217]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.0.213

Jun 11 11:31:17 ha1 Keepalived_healthcheckers[9216]: Netlink reflector reports IP 192.168.0.213 added

Jun 11 11:31:22 ha1 Keepalived_vrrp[9217]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.0.213

最后拔掉网线正常了，原因是局域网中存在该虚拟ip。