在windows下作nginx负载均衡测试。
nginx的配置文件如下：
worker_processes 1;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
upstream localhost {
server 127.0.0.1:8080 weight=1 max_fails=2 fail_timeout=30s;
server 127.0.0.1:8081 weight=1 max_fails=2 fail_timeout=30s;
}
sendfile on;
keepalive_timeout 65;
server {
listen 80;
server_name localhost;
listen 80;
server_name localhost;
location /{
proxy_pass http://localhost;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}
遇到这个问题，搜索网络， 发现网上也有人遇到同样的问题， 问题描述如下：
用了nginx负载均衡后，在两台tomcat正常运行的情况下，访问http://localhost 速度非常迅速，通过测试程序也可以看出是得到的负载均衡的效果，但是我们试验性的把其中一台tomcat（server localhost:8080）关闭后，再查看http://localhost，发现反应呈现了一半反映时间快，一半反映时间非常非常慢的情况，但是最 后都能得到正确结果。
然后我又把关闭的那吧tomcat实例恢复，此时再访问http://localhost，又可以很快的访问，负载均衡也运行正常了！郁闷！
分析怀疑可能是nginx将一半的左右的请求仍然发到了宕掉的tomcat实例上了，然后由于转发到宕掉的tomcat没有反映，nginx又重新分发到其它实例上处理。
但是这个时间也太长了。当有一台宕机后，访问http://localhost有时候会现了大概30s左右的响应时间，非常郁闷！
增加这么几个参数：
proxy_connect_timeout 300;
proxy_send_timeout 300;
proxy_read_timeout 300;
问题解决，主要是proxy_connect_timeout 这个参数， 这个参数是连接的超时时间。 我设置成1，表示是1秒后超时会连接到另外一台服务器。
现在贴出NGINX的配置如下，供后来人参考：
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include mime.types;
default_type application/octet-stream;
upstream localhost {
#ip_hash;
server 127.0.0.1:8081;
server 127.0.0.1:8080;
}
#log_format main '$remote_addr - $remote_user [$time_local] "$request" '
# '$status $body_bytes_sent "$http_referer" '
# '"$http_user_agent" "$http_x_forwarded_for"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
server {
listen 80;
server_name localhost;
listen 80;
server_name localhost;
location /{
proxy_pass http://localhost;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_connect_timeout 1;
proxy_read_timeout 1;
proxy_send_timeout 1;
}
#charset koi8-r;
#access_log logs/host.access.log main;
#error_page 404 /404.html;
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
# proxy the PHP scripts to Apache listening on 127.0.0.1:80
#
#location ~ .php$ {
# proxy_pass http://127.0.0.1;
#}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
#location ~ .php$ {
# root html;
# fastcgi_pass 127.0.0.1:9000;
# fastcgi_index index.php;
# fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;
# include fastcgi_params;
#}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
#location ~ /.ht {
# deny all;
#}
}
# another virtual host using mix of IP-, name-, and port-based configuration
#
#server {
# listen 8000;
# listen somename:8080;
# server_name somename alias another.alias;
# location / {
# root html;
# index index.html index.htm;
# }
#}
# HTTPS server
#
#server {
# listen 443;
# server_name localhost;
# ssl on;
# ssl_certificate cert.pem;
# ssl_certificate_key cert.key;
# ssl_session_timeout 5m;
# ssl_protocols SSLv2 SSLv3 TLSv1;
# ssl_ciphers ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
# ssl_prefer_server_ciphers on;
# location / {
# root html;
# index index.html index.htm;
# }
#}
}