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 [email protected]
   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 [email protected]
   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。