nginxkeepalive實(shí)現(xiàn)高可用熱備負(fù)載均衡

兩臺(tái)相同配置的兩臺(tái)接入服務(wù)器分別安裝NginX建議更新centos6的yumwget-O/etc/yum.repos.d/CentOS-Base.repohttp://m 運(yùn)行yummakecacheyum-yinstall yum-yinstall yum-yinstallpopt-安裝cdnginx-1.2.4./configure--help|more useraddwww./configure--user=www--group=www--prefix=/usr/local/nginx--with-http_stub_status_module--with-make&&make安裝cpcp/usr/local/etc/rc.d/init.d/keepalived/etc/rc.d/init.d/cp/usr/local/etc/sysconfig/keepalived/etc/sysconfig/mkdir/etc/keepalivedcdkeepalived-1.2.7makeechoecho"/usr/local/nginx/sbin/nginx">>/etc/rc.localecho"/etc/init.d/keepalivedstart">>/etc/rc.local配置兩臺(tái)接入服務(wù)器的NginX的配置完全一樣,主要是配置/usr/local/nginx/conf/nginx.conf的http。其中多指向是通過虛擬主機(jī)（配置http下面的server）實(shí)現(xiàn)；同一的不同虛擬通過每個(gè)server下面的不同location實(shí)現(xiàn)；到后端的服務(wù)器在http下面配置upstream,然后在server或location中通過proxypass。要實(shí)現(xiàn)前面規(guī)劃的接入方式，http的配置如下：下面的配置是202的httphttp default_typeapplication/octet-{server}{serverserver}serverlisten80;location/{proxy_pass};;}首先用IP前表中各個(gè)應(yīng)用服務(wù)器的配置nginxnginxtnginx正確，同時(shí)也告訴了你配置文件得路徑：#nginx-tnginx:theconfigurationfile 配置按照上面的安裝方法，keepalived的配置文件在/etc/keepalived/keepalived.conf。!ConfigurationFileforkeepalivedglobal_defs{}vrrp_instance{stateMASTERinterfaceeth0priorityadvert_int1auth_pass}{}}!ConfigurationFileforkeepalivedglobal_defs{}vrrp_instance{stateBACKUPinterfaceeth0priorityadvert_int1auth_pass}{}}先后在主、從服務(wù)器上啟動(dòng)keepalivedetc/init.d/keepalivedIPip停止主服務(wù)器上的keepalivedetc/init.d/keepalivedstop然后在從服務(wù)器上查看是否已經(jīng)綁定了虛擬IP：啟動(dòng)主服務(wù)器上的keepalived讓keepalivedNginX的狀經(jīng)過前面的配置，如果主服務(wù)器的keepalived停止服務(wù)，從服務(wù)器會(huì)自動(dòng)接管VIP對(duì)外服務(wù)；一旦主服務(wù)器的keepalived恢復(fù)，會(huì)重新接管VIP。但這并不是需要的，需要的是當(dāng)NginX停止服務(wù)的時(shí)候能夠自動(dòng)切換。keepalived支持配置，可以通過NginX的狀態(tài)，如果狀態(tài)不正常則進(jìn)行一系列的操作，最終仍不能恢復(fù)NginX則殺掉keepalived，使得從服務(wù)器能如何NginX的狀最簡單的做法是NginX進(jìn)程，更靠譜的做法是檢查NginX端口，最靠譜的做法是檢查多個(gè)url能否獲取到頁面。根據(jù)上述策略很容易寫出。這里使用nmap檢查nginx端口來判斷nginx的狀#checknginxserverstatusnmaplocalhost-p$PORT|grep"$PORT/tcpopen"#echo$?if[$?-ne0$NGINX-ssleepnmaplocalhost-p$PORT|grep"$PORT/tcpopen"[$?-ne0]&&/etc/init.d/keepalivedstop主 vrrp_script{scriptinterval1weight-}{}!ConfigurationFilefor}vrrp_script{scriptinterval1weight-}vrrp_instance{stateMASTERinterfaceeth0priorityadvert_int1auth_typePASSauth_pass1111}{}{}}更進(jìn)一步，為了避免啟動(dòng)keepalived之前沒有啟動(dòng)nginx,/etc/init.d/keepalived的start中首先啟動(dòng)start()start()sleep3ech