負(fù)載均衡服務(wù)器

Nginx的反向代理功能配置一個nginx負(fù)載均衡服務(wù)器，后端有三個服務(wù)節(jié)點，提供web服務(wù)。
搭建環(huán)境：
系統(tǒng)redhat系統(tǒng)5.4
（1）搭建前準(zhǔn)備：
四臺linux主機(jī)
DNS:192.168.1.150
web:192.168.1.121
web:192.168.1.125
web:192.168.1.126
nginx:192.168.1.120用nginx搭建負(fù)載均衡
注明：
在這里主要介紹nginx使用，以上幾臺請參考其它配置文件來做。
再要搭建nginx負(fù)載時首先做好域名解析：注明：其他三個web不需要做什么域名解析，
A記錄index.htm;
#}
error_page404/404.html;
#redirectservererrorpagestothestaticpage/50x.html
#
#error_page500502503504/50x.html;
#location=/50x.html{
#roothtml;
#}
#proxythePHPscriptstoApachelisteningon127.0.0.1:80
#
#location~\.php${
#proxy_pass127.0.0.1;
#}
#passthePHPscriptstoFastCGIserverlisteningon127.0.0.1:9000
#
#location~\.php${
#roothtml;
#fastcgi_pass127.0.0.1:9000;
#fastcgi_indexindex.php;
#fastcgi_paramSCRIPT_FILENAME/scripts$fastcgi_script_name;
#includefastcgi_params;
#}
#denyaccessto.htaccessfiles,ifApache'sdocumentroot
#concurswithnginx'sone
#
#location~/\.ht{
#denyall;
#}
}
#anothervirtualhostusingmixofIP-,name-,andport-basedconfiguration
#
#server{
#listen8000;
#listensomename:8080;
#server_namesomenamealiasanother.alias;
#location/{
#roothtml;
#indexindex.htmlindex.htm;
#}
#}
#HTTPSserver
#
#server{
#listen443;
#server_namelocalhost;
#sslon;
#ssl_certificatecert.pem;
#ssl_certificate_keycert.key;
#ssl_session_timeout5m;
#ssl_protocolsSSLv2SSLv3TLSv1;
#ssl_ciphersALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
#ssl_prefer_server_cipherson;
#location/{
#roothtml;
#indexindex.htmlindex.htm;
#}
#}
http
{
upstream;
#root/web/wwwroot;
location/{
proxy_pass