一.keepalived
keepalived是保證集群高可用的服務(wù)軟件,網(wǎng)絡(luò)中優(yōu)先級高的節(jié)點為master負(fù)責(zé)響應(yīng)vip的arp包,將vip和mac地址映射關(guān)系告訴網(wǎng)絡(luò)內(nèi)其他主機(jī),還會以多播的形式向網(wǎng)絡(luò)中發(fā)送vrrp通告,告知自己的優(yōu)先級。backup節(jié)點只負(fù)責(zé)處理master發(fā)出的多播包,當(dāng)發(fā)現(xiàn)master的優(yōu)先級沒自己高,或者沒收到master的vrrp通告時,backup將自己切換到master狀態(tài)。
二.環(huán)境搭建
1.使用臨時快照創(chuàng)建兩臺虛擬機(jī),以下操作兩臺虛擬機(jī)都需要執(zhí)行
faramita2016@linux-l9e6:~>?qemu-kvm?-cpu?host?-m?512?-hda?vdisk.img?-net?nic?-net?bridge,br=br0?-snapshot?-nographic
2.設(shè)置虛擬機(jī)靜態(tài)ip
root@debian:~#?cat?/etc/network/interfaces #?the?primary?network?interface allow-hotplug?ens3 #iface?ens3?inet?dhcp iface?ens3?inet?static address?10.0.0.3??//?設(shè)置ip netmask?255.0.0.0 gateway?10.0.0.1 hwaddress?ether?52:54:00:12:34:53??//?設(shè)置mac地址
3.激活網(wǎng)卡ip
root@debian:~#?ip?addr?del?10.0.0.8/8?dev?ens3??//?刪除客戶機(jī)原有ip root@debian:~#?ifdown?ens3 root@debian:~#?ifup?ens3
4.安裝nginx、keepalived
root@debian:~#?apt-get?install?-y?nginx?keepalived
5.修改/var/www/html/index.nginx-debian.html文件,添加當(dāng)前虛擬機(jī)ip,用于標(biāo)記實際響應(yīng)的服務(wù)器
root@debian:~#?vi?/var/www/html/index.nginx-debian.html? …… <h1>welcome?to?nginx!?10.0.0.3</h1> ……
三.軟件配置
主節(jié)點虛擬機(jī)(10.0.0.3),備用節(jié)點虛擬機(jī)(10.0.0.4),虛擬ip(10.0.0.100)
1.在主節(jié)點虛擬機(jī),編輯/etc/keepalived/keepalived.conf文件
root@debian:~#?cat?/etc/keepalived/keepalived.conf? global_defs?{ ??router_id?ri_1??//?標(biāo)識當(dāng)前keepalived節(jié)點 } vrrp_script?chk_nginx?{ ??script?"/root/chk_nginx.sh"??//?定義監(jiān)控腳本 ??interval?2??//?執(zhí)行監(jiān)控腳本的鬧中間隔時間 } vrrp_instance?vi_1?{ ??state?master??//?設(shè)置節(jié)點為主節(jié)點,節(jié)點的初始狀態(tài) ??interface?ens3??//?設(shè)置綁定虛擬ip的網(wǎng)絡(luò)接口 ??virtual_router_id?50??//?vrrp組名,指明節(jié)點同屬一個組 ??priority?100??//?節(jié)點優(yōu)先級,主節(jié)點應(yīng)當(dāng)高于備用節(jié)點 ??advert_int?1??//?組播信息發(fā)送間隔 ??#nopreempt??//?禁止搶占服務(wù),只對備用節(jié)點生效,主節(jié)點根據(jù)priority優(yōu)先級進(jìn)行搶占,不受nopreempty控制 ??authentication?{ ????auth_type?pass??//?設(shè)置認(rèn)證方式 ????auth_pass?123456??//?密碼 ??} ??virtual_ipaddress?{ ????10.0.0.100/24??//?設(shè)置vip ??} ??track_script?{??//?調(diào)用監(jiān)控腳本 ????chk_nginx ??} }
2.在備用節(jié)點虛擬機(jī),編輯/etc/keepalived/keepalived.conf文件,除以下項,其它與主節(jié)點相同
state?backup??//?設(shè)置節(jié)點為主節(jié)點,節(jié)點的初始狀態(tài) ??priority?10??//?節(jié)點優(yōu)先級
3.在所有節(jié)點執(zhí)行,創(chuàng)建監(jiān)控腳本,編輯/root/chk_nginx.sh文件
root@debian:~#?vi?/root/chk_nginx.sh? #!/bin/bash a=`ps?-c?nginx?--no-header?|?wc?-l` if?[?$a?-eq?0?] then ??/etc/init.d/keepalived?stop fi
四.驗證服務(wù)
1.主節(jié)點虛擬機(jī),啟動nginx和keepalived服務(wù)
root@debian:~#?/etc/init.d/nginx?start root@debian:~#?/etc/init.d/keepalived?start
執(zhí)行ip a命令,主節(jié)點網(wǎng)卡ens3已綁定vip(10.0.0.100)
2.在備用節(jié)點虛擬機(jī),啟動nginx和keepalived服務(wù)
root@debian:~#?/etc/init.d/nginx?start root@debian:~#?/etc/init.d/keepalived?start
執(zhí)行ip a命令,備用節(jié)點網(wǎng)卡ens3未綁定vip(10.0.0.100)
3.宿主機(jī)瀏覽器訪問http://10.0.0.100
出現(xiàn)10.0.0.3的網(wǎng)頁,說明keepalived服務(wù)已生效,vip已綁定主節(jié)點
4.在主節(jié)點虛擬機(jī),關(guān)閉nginx服務(wù),模擬宕機(jī)
root@debian:~#?/etc/init.d/nginx?stop
執(zhí)行ip a命令,主節(jié)點網(wǎng)卡ens3未綁定vip(10.0.0.100)
5.在備用節(jié)點虛擬機(jī),查詢ip
執(zhí)行ip a命令,備用節(jié)點網(wǎng)卡ens3已綁定vip(10.0.0.100)
6.宿主機(jī)瀏覽器訪問http://10.0.0.100
出現(xiàn)10.0.0.4的網(wǎng)頁,說明keepalived服務(wù)已生效,vip已綁定備用節(jié)點