在上一個實驗的基礎上LVS/DR
(NTA,DR HA 都是用 nginx 服務操作的,省去了安裝nginx安裝配置)
lvs雖然已經配置成功也實現了負載均衡,但是我們測試的時候發現,當某臺real server把httpd進程停掉,那麼director照樣會把請求轉發過去,這樣就造成了某些請求不正常。所以需要有一種機制用來檢測real server的狀態,這就是keepalived。它的作用除了可以檢測rs狀態外,還可以檢測備用director的狀態,也就是說keepalived(集HA+LB於一體)可以實現ha集羣的功能,當然了也需要一臺備用director.
實驗環境:三臺虛擬機,10.72.4.48 (dir/master),10.72.4.39(rs2&slave),10.72.4.37 (rs2)
[root@dir ~]# ipvsadm -C #清空之前的規則
[root@dir ~]# yum install -y keepalived #安裝keepalived
[root@dir ~]# vim /etc/keepalived/keepalived.conf
state MASTER #備用服務器上爲 BACKUP
interface eth0
virtual_router_id 51
priority 100 #備用服務器上爲90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.72.4.100
}
}
virtual_server 10.72.4.100 80 {
delay_loop 6 #(每隔10秒查詢realserver狀態)
lb_algo wlc #(lvs 算法)
lb_kind DR #(Direct Route)
persistence_timeout 60 #(同一IP的連接60秒內被分配到同一臺realserver)
protocol TCP #(用TCP協議檢查realserver狀態)
real_server 10.72.4.37 80 {
weight 100 #(權重)
TCP_CHECK {
connect_timeout 10 #(10秒無響應超時)
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 10.72.4.39 80 {
weight 100
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
------------------------------------------------
[root@dir ~]# scp /etc/keepalived/keepalived.conf 10.72.4.39:/etc/keepalived/keepalived.conf #拷貝到從上
[root@rs2 ~]# vim /etc/keepalived/keepalived.conf #只改以下兩處,其他地方不都不用改
vrrp_instance VI_1 {
state BACKUP #備用服務器上爲 BACKUP
interface eth0
virtual_router_id 51
priority 90 #備用服務器上爲90
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
10.72.4.100
}
}
------------------------------------------
[root@dir ~]# /etc/init.d/keepalived start
Starting keepalived: [ OK ]
[root@rs2 ~]# /etc/init.d/keepalived start
Starting keepalived: [ OK ]
[root@rs1 ~]vim /usr/local/sbin/lvs_nat.sh #編譯腳本
#! /bin/bash
vip=10.72.4.100
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip lo:0
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
[root@rs1 ~]sh /usr/local/sbin/lvs_nat.sh #執行腳本
[root@rs2 ~]vim /usr/local/sbin/lvs_nat.sh #編譯腳本
#! /bin/bash
vip=10.72.4.100
ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
route add -host $vip lo:0
echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
[root@rs2 ~]sh /usr/local/sbin/lvs_nat.sh #執行腳本
[root@dir ~]# vim /usr/local/sbin/lvs_dr.sh #編譯打開dir 上的端口轉發腳本
#! /bin/bash
echo 1 > /proc/sys/net/ipv4/ip_forward
[root@dir ~]# sh /usr/local/sbin/lvs_dr.sh #執行腳本
[root@rs2 ~]# /etc/init.d/nginx stop #停掉 rs2 上的nginx ,
Stopping nginx: [ OK ]
#停掉rs2 上的nginx 後,IE 刷新 10.72.4.100,不會再出現rs2 上的內容。且主服務器也會把rs2 的IP 踢除,重新啓動rs2 上的nginx 服務,會恢復正常。
--------------------------------------------------------
[root@dir ~]# /etc/init.d/keepalived stop #停掉主dir上的 keepalived ,rs2從上的keepalived就會啓動,取代dir 成爲主,繼續工作。
Stopping keepalived: [ OK ]
再次重新啓動主的 keepalived ,就會恢復到之前的狀態。