LVS+KEEPALIVED负载均衡

Dear 丶 2021-11-02 03:56 476阅读 0赞

LVS+KEEPALIVED负载均衡

一、     环境准备

Master-lvs：192.168.0.5

Backup-lvs：192.168.0.10

App-web01：192.168.0.15

App-web02：192.168.0.20

VIP：192.168.0.50

二、     部署master-lvs服务器

修改内核参数  vi /etc/sysctl.conf

net.ipv4.conf.lo.arp\_ignore = 1

安装ipvsadm软件

wget  [http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz][http_www.linuxvirtualserver.org_software_kernel-2.6_ipvsadm-1.24.tar.gz]

tar zxvf ipvsadm-1.24.tar.gz

cd ipvsadm-1.24

ln -s /usr/src/kernels/2.6.18-128.el5-PAE-i686   /usr/src/linux

make

make install

安装Keepalived包

ln -s /usr/src/kernels/2.6.18-128.el5-PAE-i686 /usr/src/linux

wget http://www.keepalived.org/software/keepalived-1.1.17.tar.gz  
tar -xvzf keepalived-1.1.17.tar.gz  
cd keepalived-1.1.17  
./configure --sysconfdir=/etc/ --sbindir=/usr/sbin/

make&make install

修改 /etc/keepalived/keepalived.conf

!Configuration File for keepalived

global\_defs \{

notification\_email \{

lvze@163.com

notification\_email\_from lzspf@163.com

smtp\_server 127.0.0.1

smtp\_connect\_timeout 30

router\_id LVS\_DEVEL\_1

vrrp\_instance VI\_1 \{

state MASTER

interface eth0

virtual\_router\_id 51

priority 150

advert\_int 1

authentication \{

auth\_type PASS

auth\_pass 1234

virtual\_ipaddress \{

192.168.0.50

virtual\_server 192.168.0.50 80 \{

delay\_loop 6

lb\_algo wrr

lb\_kind DR

persistence\_timeout 50

protocol TCP

real\_server 192.168.0.15 80 \{

weight 3

TCP\_CHECK \{

connect\_timeout 10

nb\_get\_retry 3

delay\_before\_retry 3

connect\_port 80

real\_server 192.168.0.20 80 \{

weight 3

TCP\_CHECK \{

connect\_timeout 10

nb\_get\_retry 3

delay\_before\_retry 3

connect\_port 80

三、     部署Backup-lvs服务器

安装ipvsadm以及keepalived的包

内核参数需要修改如下值：

net.ipv4.conf.lo.arp\_ignore = 1

将master-lvs上的配置文件拷贝到Backup-lvs服务器上

在master-lvs上运行如下命令拷贝到backup-lvs上面前提是ipvsadm和keepalived已经安装。

Scp /etc/keepalived/keepalived.conf 192.168.0.10:/etc/keepalived/

Scp /sbin/lvsdr.sh 192.168.0.10:/sbin

可能需要输入密码进行文件的传输

主要修改keepalived的配置文件,标红的位置是需要修改的。

!Configuration File for keepalived

global\_defs \{

notification\_email \{

lvze@163.com

notification\_email\_from lzspf@163.com

smtp\_server 127.0.0.1

smtp\_connect\_timeout 30

router\_id LVS\_DEVEL\_2

vrrp\_instance VI\_1 \{

state BACKUP

interface eth0

virtual\_router\_id 51

priority 100

advert\_int 1

authentication \{

auth\_type PASS

auth\_pass 1234

virtual\_ipaddress \{

192.168.0.50

virtual\_server 192.168.0.50 80 \{

delay\_loop 6

lb\_algo wrr

lb\_kind DR

persistence\_timeout 50

protocol TCP

real\_server 192.168.0.15 80 \{

weight 3

TCP\_CHECK \{

connect\_timeout 10

nb\_get\_retry 3

delay\_before\_retry 3

connect\_port 80

real\_server 192.168.0.20 80 \{

weight 3

TCP\_CHECK \{

connect\_timeout 10

nb\_get\_retry 3

delay\_before\_retry 3

connect\_port 80

分别在master和backup运行keepalived服务

/etc/init.d/keepalived start

四、     配置后端WEB服务器

在192.168.0.15和192.168.0.20上分别建立如下脚本。

vi /sbin/realdr.sh

\#!/bin/bash

VIP=172.16.83.126

/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up

/sbin/route add -host $VIP dev lo:0

echo "1">/proc/sys/net/ipv4/conf/default/arp\_ignore

echo "2">/proc/sys/net/ipv4/conf/default/arp\_announce

echo "1">/proc/sys/net/ipv4/conf/all/arp\_ignore

echo "2">/proc/sys/net/ipv4/conf/all/arp\_announce

sysctl -p

配置权限

chmod 755 /sbin/realdr.sh

在两台web服务器上分别执行其指命。

/sbin/realdr.sh start

五、     模拟故障测试

测试keepalived

1 当我把master的lvs服务关掉的时候，会将用户请求自动切换到backup上面进行工作。

停止Master-LVS的keepalived服务，人为造成故障  
\[root@Master-LVS\]\# service keepalived stop

这时查看Backup-LVS的log信息  
\[root@Backup-LVS\]\# tail -f /var/log/message

[?][Link 1]\[Copy to clipboard\]  LOG

<table> 
 <tbody> 
 <tr> 
 <td> Sep&nbsp; 3 11:23:28 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Transition to MASTER STATE Sep&nbsp; 3 11:23:29 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering MASTER STATE Sep&nbsp; 3 11:23:29 localhost Keepalived_vrrp: VRRP_Instance(VI_1) setting protocol VIPs. Sep&nbsp; 3 11:23:29 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.108.180 Sep&nbsp; 3 11:23:29 localhost Keepalived_vrrp: Netlink reflector reports IP 192.168.0.50 added Sep&nbsp; 3 11:23:29 localhost Keepalived_healthcheckers: Netlink reflector reports IP 192.168.0.50 added Sep&nbsp; 3 11:23:34 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.0.50 </td> 
 </tr> 
 </tbody> 
</table>

由日志可以看出，Backup-LVS监测到Master-LVS故障后立即将自己的身份切换为Master然后将VIP设置到自己的eth0端口上并发送ARP广播。

现在我手动将Master-LVS的keepalived的服务起来，然后再查看Backup-LVS的log信息  
\[root@Master-LVS\]\# service keepalived start

\[root@Backup-LVS\]\# tail -f /var/log/message

[?][Link 1]\[Copy to clipboard\]  LOG

<table> 
 <tbody> 
 <tr> 
 <td> Sep&nbsp; 3 11:30:44 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Received higher prio advert Sep&nbsp; 3 11:30:44 localhost Keepalived_vrrp: VRRP_Instance(VI_1) Entering BACKUP STATE Sep&nbsp; 3 11:30:44 localhost Keepalived_vrrp: VRRP_Instance(VI_1) removing protocol VIPs. Sep&nbsp; 3 11:30:44 localhost Keepalived_vrrp: Netlink reflector reports IP 192.168.0.50 removed Sep&nbsp; 3 11:30:44 localhost Keepalived_healthcheckers: Netlink reflector reports IP 192.168.0.50 removed </td> 
 </tr> 
 </tbody> 
</table>

由Backup-LVS的日志可以看到，其检测到比自己优先级高的实例后将自己的身份切换成了Backup，然后将VIP从eth0端口移除，并发送心跳给Master-LVS。

测试lvs

1当我把web服务关掉的时候，lvs上面会显示web消失，当启用后，web会自动显示

Web20关闭后：

\[root@localhost ~\]\# ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddressort Scheduler Flags

-> RemoteAddressort           Forward Weight ActiveConn InActConn

TCP  192.168.0.50:80 wrr

-> 192.168.0.15:80             Route   10     0          0

\[root@localhost ~\]\# ipvsadm -ln

Web20启用后：

root@localhost ~\]\# ipvsadm -ln

IP Virtual Server version 1.2.1 (size=4096)

Prot LocalAddressort Scheduler Flags

-> RemoteAddress:Port           Forward Weight ActiveConn InActConn

TCP  192.168.0.50:80 wlc

-> 192.168.0.15:80             Route   1      0          0

-> 192.168.0.20:80             Route   1      0          0

[http_www.linuxvirtualserver.org_software_kernel-2.6_ipvsadm-1.24.tar.gz]: http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz
[Link 1]: http://www.ericbess.com/ericblog/2008/03/03/wp-codebox/#examples