# ./nginx -V
Tengine version: Tengine/2.1.1 (nginx/1.6.2)
built by gcc 4.4.7 20120313 (Red Hat 4.4.7-11) (GCC) 
TLS SNI support enabled
configure arguments: --prefix=/apps/tengine-2.1.1
loaded modules:
    ngx_core_module (static)
    ngx_errlog_module (static)
    ngx_conf_module (static)
    ngx_dso_module (static)
    ngx_syslog_module (static)
    ngx_events_module (static)
    ngx_event_core_module (static)
    ngx_epoll_module (static)
    ngx_procs_module (static)
    ngx_proc_core_module (static)
    ngx_openssl_module (static)
    ngx_regex_module (static)
    ngx_http_module (static)
    ngx_http_core_module (static)
    ngx_http_log_module (static)
    ngx_http_upstream_module (static)
    ngx_http_static_module (static)
    ngx_http_autoindex_module (static)
    ngx_http_index_module (static)
    ngx_http_auth_basic_module (static)
    ngx_http_access_module (static)
    ngx_http_limit_conn_module (static)
    ngx_http_limit_req_module (static)
    ngx_http_geo_module (static)
    ngx_http_map_module (static)
    ngx_http_split_clients_module (static)
    ngx_http_referer_module (static)
    ngx_http_rewrite_module (static)
    ngx_http_ssl_module (static)
    ngx_http_proxy_module (static)
    ngx_http_fastcgi_module (static)
    ngx_http_uwsgi_module (static)
    ngx_http_scgi_module (static)
    ngx_http_memcached_module (static)
    ngx_http_empty_gif_module (static)
    ngx_http_browser_module (static)
    ngx_http_user_agent_module (static)
    ngx_http_upstream_ip_hash_module (static)
    ngx_http_upstream_consistent_hash_module (static)
    ngx_http_upstream_check_module (static) #nginx的健康检查模块安装了
    ngx_http_upstream_least_conn_module (static)
    ngx_http_reqstat_module (static)
    ngx_http_upstream_keepalive_module (static)
    ngx_http_upstream_dynamic_module (static)
    ngx_http_stub_status_module (static)
    ngx_http_write_filter_module (static)
    ngx_http_header_filter_module (static)
    ngx_http_chunked_filter_module (static)
    ngx_http_range_header_filter_module (static)
    ngx_http_gzip_filter_module (static)
    ngx_http_postpone_filter_module (static)
    ngx_http_ssi_filter_module (static)
    ngx_http_charset_filter_module (static)
    ngx_http_userid_filter_module (static)
    ngx_http_footer_filter_module (static)
    ngx_http_trim_filter_module (static)
    ngx_http_headers_filter_module (static)
    ngx_http_upstream_session_sticky_module (static)
    ngx_http_copy_filter_module (static)
    ngx_http_range_body_filter_module (static)
    ngx_http_not_modified_filter_module (static)

uptream name { 
        server 192.168.0.21:80;
        server 192.168.0.22:80;
        check interval=3000 rise=2 fall=5 timeout=1000 type=http;        
 }
#上面配置的意思是，对name这个负载均衡条目中的所有节点，每个3秒检测一资，请求2资下正常则标记realserver状态为up,如果检测5次都失败，则标记realserver的状态为down，超时间为1秒。