LVS+keepalived
四台centos5.5
VIP 192.168.0.82
lvs 192.168.0.81 192.168.0.74
web 192.168.0.72 192.168.0.73
LVS服务器(DR模式，所有IP都在内网)
ln -s /usr/src/kernels/2.6.18-53.e15-i686/ /usr/src/linux
#如果/usr/src/kernels/目录空先安装kernel-devel
#yum install kernel-devel
yum install ipvsadm
ipvsadm
lsmod |grep ip_vs
echo "1" > /proc/sys/net/ipv4/ip_forward
#/bin/bash
VIP=192.168.0.82
WEB1=192.168.0.72
WEB2=192.168.0.73
case "$1" in
start)
/sbin/ifconfig eth0:0 $VIP broadcast $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev eth0:0
/sbin/ipvsadm -C
/sbin/ipvsadm -A -t $VIP:80 -s rr
/sbin/ipvsadm -a -t $VIP:80 -r $WEB1 -g
/sbin/ipvsadm -a -t $VIP:80 -r $WEB2 -g
touch /var/lock/subsys/ipvsadm >/dev/null 2>&1
echo "lvs status-------------------[OK]"
;;
stop)
/sbin/ipvsadm -C
/sbin/ifconfig eth0:0 down
route del $VIP
rm -rf /var/lock/subsys/ipvsadm >/dev/null 2>&1
echo "lvs stop"
;;
status)
if [ ! -e /var/lock/subsys/ipvsadm ];then
echo "lvs stop"
exit 1
else
echo "lvs status-------------------[OK]"
fi
;;
*)
echo "Usage: $0 {start|stop|status}"
exit 1
;;
esac
WEB服务器(两台一致)
#!/bin/bash
#description:start realserver
#chkconfig
VIP=192.168.0.82
/etc/rc.d/init.d/functions
case "$1" in
start)
echo " start LVS of REALServer"
/sbin/ifconfig lo:0 $VIP1 broadcast $VIP1 netmask 255.255.255.255 up
/sbin/route add -host $VIP1 dev lo:0
echo "1" >/proc/sys/net/ipv4/ip_forward
echo "1" >/proc/sys/net/ipv4/conf/eth0/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/eth0/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
;;
stop)
/sbin/ifconfig lo:0 down
echo "close LVS Directorserver"
echo "0" >/proc/sys/net/ipv4/ip_forward
echo "0" >/proc/sys/net/ipv4/conf/eth0/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/eth0/arp_announce
echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac
编译 keepalived-1.1.17(版本不可过高)
yum install libnl-devel
./configure
make
make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ #设置为service方式启动
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
/etc/init.d/keepalived start #启动keepalived
vi /etc/rc.local #添加为开机自启动
/usr/local/sbin/keepalived -D -f /etc/keepalived/keepalived.conf
# sed -i 's#net.ipv4.ip_forward = 0#net.ipv4.ip_forward = 1#' /etc/sysctl.conf #开启内核转发功能
# sysctl -p #查看是否开启内核转发
mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf_bak #备份原始配置文件
vi /etc/keepalived/keepalived.conf
========================================================
!Configuration File for keepalived
global_defs {
#notification_email {
# [email protected] #填写自己的邮箱出现故障接收报警邮件用
#}
#notification_email_from [email protected]
#smtp_server 127.0.0.1
#smtp_connect_timeout 30
router_id LVS_01 #备份服务器改为LVS_02
}
vrrp_instance VI_1 {
state MASTER #备份服务器上MASTER为BACKUP
interface eth0
#lvs_sync_daemon_inteface eth1
virtual_router_id 51
priority 100 #备份服务上优先级要低于100，如改为90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.0.82 #这里填写VIP地址，也可添加多个VIP
}
}
virtual_server 192.168.0.82 80 { #这里填写VIP地址
delay_loop 6
lb_algo rr
lb_kind DR
#nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.0.72 80 { #这里是真实服务器的IP
weight 1
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.0.73 80 { #这里是第二台真实服务器的IP
weight 2
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
========================================================
keepalived.conf 文件详解
安装完成之后，生成的配置文件放置于:/usr/local/keepalived/etc/keepalived/keepalived.conf
官方提供了不少模板性的配置文件：/usr/local/keepalived/etc/keepalived/samples
建议将配置文件放置于: /etc/keepalived/keepalived.conf
如果运用不指定配置文件，他可以直接调用/etc/keepalived/keepalived.conf中的配置文件
接下来，详细说明配置文件中的各项含义：
#全局定义块，以下模块不可省略，必须存在。
global_defs {
notification_email {
email #如有故障，发邮件报警的地址，一般不采用，可以随意填写
}
notification_email_from email
smtp_server host
smtp_connect_timeout num #邮件服务链接超时的最长时间
lvs_id string #Lvs负载均衡器标识，在一个网络里面，请保持他是唯一性。
}
#VRRP实例定义块
vrrp_sync_group string { #确定失败切换（FailOver）包含的路由实例个数。即在有2个负载均衡器的场景，一旦某个负载均衡器失效
group {
string #备用的负载均衡的服务器名
string
}
vrrp_instance string { #前面定义的后备的负载均衡的服务器名
state MASTER|BACKUP #只有MASTER和BACKUP两种状态，都必须保持大写。
interface string #进行通信的端口，如eth0,eth1
mcast_src_ip @IP #真实的IP地址
lvs_sync_daemon_interface string #负载均衡器之间的监控接口。如果采用DR模式，可以保持和通信端口一致。
virtual_router_id num #这个标识是同一个vrrp实例使用唯一的标识。即同一个vrrp_stance,MASTER和BACKUP的virtual_router_id是一致的，同时在整个vrrp内是唯一的。
priority num #权重，数值越大，权重越大，Master大于Slave。
advert_int num #Master和Slave负载均衡器之间同步检查的时间间隔，单位：秒
smtp_alert
authentication { #Master和Slave之间认证的方式
auth_type PASS|AH
auth_pass string #认证的秘密
}
virtual_ipaddress { # Block limited to 20 IP addresses
IP
IP
IP
}
virtual_ipaddress_excluded { # Unlimited IP addresses number
IP
IP
IP
}
#虚拟服务器定义块
virtual_server (@IP PORT)|(fwmark num) { #上面定义的virtual_ipaddress，需要添加端口
delay_loop num #服务健康检查周期，单位：秒
lb_algo rr|wrr|lc|wlc|sh|dh|lblc #负载均衡的调度算法方式，一般使用rr或者wlc。
lb_kind NAT|DR|TUN #负载均衡转发规则，一般采用DR
(nat_mask @IP) #地址掩码，可不填
persistence_timeout num #会话保持时间，单位：秒。如果是动态服务，建议开启。
persistence_granularity @IP
virtualhost string
protocol TCP|UDP #通信协议，有
sorry_server @IP PORT
real_server @IP PORT { #真实IP地址
weight num #权重值，数值越大，权重越高，分发的可能越大。
TCP_CHECK {
connect_port num #检查端口
connect_timeout num #检查超时时间
}
}
real_server @IP PORT {
weight num
MISC_CHECK {
misc_path /path_to_script/script.sh
(or misc_path “/path_to_script/script.sh ”)
}
}
real_server @IP PORT {
weight num
HTTP_GET|SSL_GET {
url { # You can add multiple url block
path alphanum
digest alphanum
}
connect_port num
connect_timeout num
nb_get_retry num
delay_before_retry num
}
}
}
keepalived 实例
Master 服务器
#guration File for keepalived (Master Server)
#writed by eric.w.t 2011/04/12
###################################
# global define
###################################
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
####################################
# vrrp define
####################################
vrrp_sync_group VGM {
group {
VI_1
}
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 110
priority 100
advert_int 1
virtual_ipaddress {
10.249.0.208
}
}
#####################################
# virtual machine setting
#####################################
virtual_server 10.249.0.208 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
nat_mask 255.255.255.0
protocol TCP
persistence_timeout 20
real_server 10.249.0.254 80 {
weight 10
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
Slave 服务器配置
#guration File for keepalived (Slave Server)
#writed by eric.w.t 2011/04/12
###################################
# global define
###################################
global_defs {
notification_email {
[email protected]
}
notification_email_from [email protected]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
####################################
# vrrp define
####################################
vrrp_sync_group VGM {
group {
VI_1
}
}
vrrp_instance VI_1 {
state SLAVE
interface eth0
virtual_router_id 110
priority 99
advert_int 1
virtual_ipaddress {
10.249.0.208
}
}
#####################################
# virtual machine setting
#####################################
virtual_server 10.249.0.208 80 {
delay_loop 6
lb_algo rr
lb_kind NAT
nat_mask 255.255.255.0
protocol TCP
persistence_timeout 20
real_server 10.249.0.254 80 {
weight 10
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
参考文档 ：
http://www.keepalived.org/documentation.html
#调用检测脚本
vrrp_script check_run {
script "/root/keepalived_check_mysql.sh"
interval 5
}