之前用ssh寫過一個後端服務介面，通過一個api向外部提供天氣預報資料，但是併發量一旦大了，反應時長就會變的很長，也容易爆記憶體不足的問題。後來瞭解到node.js 處理高併發的優勢，就拿java+tomcat 和node.js 做了實驗對比。
整體框架結構為，前端nginx 做反向代理，轉向兩個http server，httpserver 從快取中去讀取資料，並立馬返回，服務端指令碼定時去更新快取中的資料，為確保每一個客戶端訪問的資料的一致性，nginx配置如下。
nginx.conf

#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;

    #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;


    upstream weather.deyuan.com { 
    ip_hash
 
;
    server 192.168.6.120:3000; 
    server 192.168.6.80:3000; 
    }
    server {
        listen       83;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
           proxy_pass http://weather.deyuan.com; 
           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  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 ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}

}

express 路由配置:

var express = require('express');
var redis = require('redis');
var util=require("util")
var client = redis.createClient(6379,'127.0.0.1');
var router = express.Router();

/**
 * 本級目錄對應上一級目錄為WeatherApi
 * 為天氣預報相關介面
 */




/* 天氣預報資料介面 引數cityName 為城市名稱      */
router.get('/getData', function(req, res, next) {
    cityName = req.query.cityName;
    client.get(cityName, function (err, reply) {
        res.send(reply);

    });
})

/* 天氣預報Token介面   */
router.get('/getToken', function (req, res,next) {
    var str=util.format('%s=%s&%s=%s', 'host_lbs', 'v.juhe.cn', 'key_lbs','9c6b8aaa4a399952faad5765313849de');
    res.send(str);
})

module.exports = router;