LVS之DR+ldirectord实现对与后端服务器有健康检查的负载均衡-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_42732013/article/details/82860895

本文详细介绍了如何利用LVS的DR模式结合ldirectord进行负载均衡配置，实现对后端服务器的健康检查。在Red Hat Enterprise Linux 6.5环境下，通过安装ldirectord软件、配置虚拟服务、添加RealServer以及设置VIP，确保在服务器异常时能够自动切换，保持服务的高可用性。同时，通过curl测试验证了在RealServer停机时，服务能够平滑地从其他服务器接管。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

关于 ldirectord

ldirectord 用来实现LVS负载均衡资源在主、备节点间的故障转移。在首次启动时，ldirectord可以自动创建IPVS表。此外，它还可以监控各 RealServer的运行状态，一旦发现某RealServer运行异常时，还可以将其从IPVS表中移除。

ldirectord 进程通过向RealServer的RIP发送资源访问请求并通过由RealServer返回的响应信息来确定RealServer的运行状态。在 Director上，每一个VIP需要一个单独的ldirectord进程。如果RealServer不能正常响应Director上 ldirectord的请求，ldirectord进程将通过ipvsadm命令将此RealServer从IPVS表中移除。而一旦 RealServer再次上线，ldirectord会将其重新添加至IPVS表中。

例如，为了监控一组提供web服务的RealServer，ldirectord进程使用HTTP协议请求访问每台RealServer上的某个特定网页。 ldirectord进程根据自己的配置文件中事先定义的RealServer正常响应结果来判断当前的返回结果是否正常。比如，在每台web服务器的网站目录中存放一个页面".ldirectord.html"，其内容为"Nice"，ldirectord进程每隔一段时间就访问一次此网页，并根据获取到的响应信息来判断RealServer的运行状态是否正常。如果其返回的信息不是"Nice"，则表明服务不正常

服务环境搭建

实验主机环境介绍：

主机使用版本： redhat rhe6.5

iptables stop 以及 selinux disablesl

主机ip ：172.25.254.79

Load Balance ： wyx1 ：172.25.79.1 VIP 172.25.79.111 （对外开放）

Realserver1 ：wyx2 ： 172.25.79.2 vip 172.25.79.111 （仅对同一WLAN用户开放）

Realserver1 ：wyx3： 172.25.79.3 vip 172.25.79.111 （仅对同一WLAN用户开放）

安装ldirectord 软件

[root@wyx1 ~]# yum install ldirectord-3.9.5-3.1.x86_64.rpm -y

查找ldirectord配置文件

[root@wyx1 /]# rpm -ql ldirectord
/etc/ha.d
/etc/ha.d/resource.d
/etc/ha.d/resource.d/ldirectord
/etc/init.d/ldirectord
/etc/logrotate.d/ldirectord
/usr/lib/ocf/resource.d/heartbeat/ldirectord
/usr/sbin/ldirectord
/usr/share/doc/ldirectord-3.9.5
/usr/share/doc/ldirectord-3.9.5/COPYING
/usr/share/doc/ldirectord-3.9.5/ldirectord.cf
/usr/share/man/man8/ldirectord.8.gz

复制配置文件到本机/etc/ha.d/

[root@wyx1 /]# cp /usr/share/doc/ldirectord-3.9.5/ldirectord.cf /etc/ha.d/

编辑配置文件/etc/ha.d/ldirectord.cf

# Global Directives
checktimeout=3
checkinterval=1
autoreload=yes
quiescent=no

# Sample for an http virtual service
virtual=172.25.79.111:80
        real=172.25.79.2:80 gate
        real=172.25.79.3:80 gate
        fallback=127.0.0.1:80 gate
        service=http
        scheduler=rr
        #persistent=600
        #netmask=255.255.255.255
        protocol=tcp
        checktype=negotiate
        checkport=80
        request="index.html"
        #receive="Test Page"

#virtualhost=www.x.y.z

配置完成开启服务

[root@wyx1 /]# /etc/init.d/ldirectord start
Starting ldirectord... success

wyx2

安装http服务

[root@wyx2 ~]# yum install httpd -y

编辑默认发布目录

[root@wyx2 ~]# cat /var/www/html/index.html
<h1>www.wyx.org: wyx2</h1>

启动http服务

[root@wyx2 ~]# /etc/init.d/httpd start
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.79.2 for ServerName
[ OK ]

添加vip

[root@wyx2 ~]# ip addr add 172.25.79.111/24 dev eth0

[root@wyx2 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:77:c2:f5 brd ff:ff:ff:ff:ff:ff
    inet 172.25.79.2/24 brd 172.25.79.255 scope global eth0
    inet 172.25.79.111/24 scope global secondary eth0
    inet6 fe80::5054:ff:fe77:c2f5/64 scope link
       valid_lft forever preferred_lft forever

对外隐藏vip

[root@wyx2 ~]# arptables -A IN -d 172.25.79.111 -j DROP

[root@wyx2 ~]# arptables -A OUT -s 172.25.79.111 -j mangle --mangle-ip-s 172.25.79.2

保存修改

[root@wyx2 ~]# /etc/init.d/arptables_jf save

wyx3 :

安装http服务

[root@wyx3 ~]# yum install httpd -y

编辑默认发布目录

[root@wyx3 ~]# cat /var/www/html/index.html
<h1>www.wyx.org: wyx3</h1>

启动http服务

[root@wyx3 ~]# /etc/init.d/httpd start
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.79.3 for ServerName
[ OK ]

添加vip

[root@wyx3 ~]# ip addr add 172.25.79.111/24 dev eth0

[root@wyx3 ~]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 52:54:00:e6:31:59 brd ff:ff:ff:ff:ff:ff
    inet 172.25.79.3/24 brd 172.25.79.255 scope global eth0
    inet 172.25.79.111/24 scope global secondary eth0
    inet6 fe80::5054:ff:fee6:3159/64 scope link
       valid_lft forever preferred_lft forever

对外隐藏vip

[root@wyx3 ~]# arptables -A IN -d 172.25.79.111 -j DROP

[root@wyx3 ~]# arptables -A OUT -s 172.25.79.111 -j mangle --mangle-ip-s 172.25.79.3

保存修改

[root@wyx3 ~]# /etc/init.d/arptables_jf save

测试

wyx2与wyx3都在工作时：

[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>

当停止wyx3时仅有wyx2在工作,

[root@wyx3 ~]# /etc/init.d/httpd stop
Stopping httpd: [ OK ]

由wyx1 的回环接口接管wyx3的服务

[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>

LVS之DR+ldirectord实现对与后端服务器有健康检查的负载均衡

[root@wyx1 ~]# yum install ldirectord-3.9.5-3.1.x86_64.rpm -y

[root@wyx1 /]# cp /usr/share/doc/ldirectord-3.9.5/ldirectord.cf /etc/ha.d/

# Global Directives checktimeout=3 checkinterval=1 autoreload=yes quiescent=no

# Sample for an http virtual service virtual=172.25.79.111:80 real=172.25.79.2:80 gate real=172.25.79.3:80 gate fallback=127.0.0.1:80 gate service=http scheduler=rr #persistent=600 #netmask=255.255.255.255 protocol=tcp checktype=negotiate checkport=80 request="index.html" #receive="Test Page"

#virtualhost=www.x.y.z

配置完成开启服务

[root@wyx1 /]# /etc/init.d/ldirectord start Starting ldirectord... success

安装http服务

[root@wyx2 ~]# yum install httpd -y

编辑默认发布目录

[root@wyx2 ~]# cat /var/www/html/index.html <h1>www.wyx.org: wyx2</h1>

启动http服务

[root@wyx2 ~]# /etc/init.d/httpd start Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.79.2 for ServerName [ OK ]

添加vip

[root@wyx2 ~]# ip addr add 172.25.79.111/24 dev eth0

对外隐藏vip

[root@wyx2 ~]# arptables -A IN -d 172.25.79.111 -j DROP

[root@wyx2 ~]# arptables -A OUT -s 172.25.79.111 -j mangle --mangle-ip-s 172.25.79.2

保存修改

[root@wyx2 ~]# /etc/init.d/arptables_jf save

wyx3 :

安装http服务

[root@wyx3 ~]# yum install httpd -y

编辑默认发布目录

[root@wyx3 ~]# cat /var/www/html/index.html <h1>www.wyx.org: wyx3</h1>

启动http服务

[root@wyx3 ~]# /etc/init.d/httpd start Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.79.3 for ServerName [ OK ]

添加vip

[root@wyx3 ~]# ip addr add 172.25.79.111/24 dev eth0

对外隐藏vip

[root@wyx3 ~]# arptables -A IN -d 172.25.79.111 -j DROP

[root@wyx3 ~]# arptables -A OUT -s 172.25.79.111 -j mangle --mangle-ip-s 172.25.79.3

保存修改

[root@wyx3 ~]# /etc/init.d/arptables_jf save

测试

[root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx3</h1> [root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx2</h1> [root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx3</h1> [root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx2</h1>

当停止wyx3时仅有wyx2在工作,

[root@wyx3 ~]# /etc/init.d/httpd stop Stopping httpd: [ OK ]

由wyx1 的回环接口接管wyx3的服务

[root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx2</h1> [root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx3</h1> [root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx2</h1> [root@foundation79 html]# curl 172.25.79.111 <h1>www.wyx.org: wyx3</h1>

完成对于系统的健康检测，在客户端不会发现该服务以终止，会显示服务还是正常运行

但是坚持不料多久wyx1就会奔溃，应为访问量太大会导致该服务器承受不了直接挂掉。

# Global Directives
checktimeout=3
checkinterval=1
autoreload=yes
quiescent=no

# Sample for an http virtual service
virtual=172.25.79.111:80
real=172.25.79.2:80 gate
real=172.25.79.3:80 gate
fallback=127.0.0.1:80 gate
service=http
scheduler=rr
#persistent=600
#netmask=255.255.255.255
protocol=tcp
checktype=negotiate
checkport=80
request="index.html"
#receive="Test Page"

[root@wyx1 /]# /etc/init.d/ldirectord start
Starting ldirectord... success

[root@wyx2 ~]# cat /var/www/html/index.html
<h1>www.wyx.org: wyx2</h1>

[root@wyx2 ~]# /etc/init.d/httpd start
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.79.2 for ServerName
[ OK ]

[root@wyx3 ~]# cat /var/www/html/index.html
<h1>www.wyx.org: wyx3</h1>

[root@wyx3 ~]# /etc/init.d/httpd start
Starting httpd: httpd: Could not reliably determine the server's fully qualified domain name, using 172.25.79.3 for ServerName
[ OK ]

[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>

[root@wyx3 ~]# /etc/init.d/httpd stop
Stopping httpd: [ OK ]

[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx2</h1>
[root@foundation79 html]# curl 172.25.79.111
<h1>www.wyx.org: wyx3</h1>