早些年 get 参数都是限制 256 个字符的。再长的话就用 POST。
由于，POST 遇到跨域访问。无法发送数据，只能选择 GET

开发环境下没有错误，部署到 Nginx + Gunicorn 的时候 发生了 400 错误
~~~~.shell
Nginx 400 request line is too large (5132 4094)
~~~~

**首先：**

* 检查 nginx 配置文件是否加入了下面的配置
```.shell
client_header_buffer_size 512k;
large_client_header_buffers 4 512k;
```

**接着：**

* 检查下 gunicorn 配置
gunicorn 默认限制 GTE 长度是 4094
~~~~.shell
$ gunicorn --help
  --limit-request-line INT
                        The maximum size of HTTP request line in bytes. [4094]
~~~~

**最后：**
重启服务

解决： Nginx 400 request line is too large (5132 4094)

####  ngxtop 是一个纯 python 实时分析 nginx 访问日志的 python 项目,并且支持 python3


## 安装
-----
```.shell
pip install ngxtop
```


## 默认输出：
-------
```.shell
~# ngxtop
running for 548 seconds, 196 records processed: 0.36 req/sec

Summary:
|   count |   avg_bytes_sent |   2xx |   3xx |   4xx |   5xx |
|---------+------------------+-------+-------+-------+-------|
|     196 |         4189.750 |   183 |     3 |     9 |     1 |

Detailed:
| request_path                                   |   count |   avg_bytes_sent |   2xx |   3xx |   4xx |   5xx |
|------------------------------------------------+---------+------------------+-------+-------+-------+-------|
| /admin/jsi18n/                                 |      16 |         2191.000 |    16 |     0 |     0 |     0 |
| /admin/weixin/article/                         |      16 |         7133.188 |    16 |     0 |     0 |     0 |
| /jet/jsi18n/                                   |      14 |         2191.000 |    14 |     0 |     0 |     0 |
| /tags/%E5%A8%B1%E4%B9%90                       |      10 |        12220.100 |    10 |     0 |     0 |     0 |
| /                                              |       5 |          652.200 |     4 |     0 |     1 |     0 |
| /admin/articles/article/                       |       5 |         7822.000 |     5 |     0 |     0 |     0 |
| /admin/articles/article/64352/                 |       2 |        15374.000 |     2 |     0 |     0 |     0 |
| /api/articles/06549522408f4603f278e1f76327d5dc |       2 |            0.000 |     2 |     0 |     0 |     0 |
| /api/articles/49fc7a754153b414677cd3bb32b2225d |       2 |            0.000 |     2 |     0 |     0 |     0 |
| /tags/%E6%AE%B5%E5%AD%90                       |       2 |        11734.000 |     2 |     0 |     0 |     0 |
```

### 查看和统计用户访问的ip

------------
```.shell
~#ngxtop top remote_addr
running for 236 seconds, 90 records processed: 0.38 req/sec

top remote_addr
| remote_addr    |   count |
|----------------+---------|
| 66.249.79.126  |      37 |
| 124.79.41.152  |      32 |
| 66.249.79.49   |      11 |
| 66.249.79.53   |       2 |
| 66.249.79.57   |       2 |
| 106.47.172.123 |       1 |
```

### 统计下当前有多少4xx和5xx的请求
-----------
```.shell
~# ngxtop -i 'status >= 400' print request status http_referer
running for 320 seconds, 9 records processed: 0.03 req/sec

request, status, http_referer:
| request                                                      |   status | http_referer   |
|--------------------------------------------------------------+----------+----------------|
| GET /articles/chun-jie-ying-yuan-da-pian-zhe HTTP/1.1        |      404 | -              |
| GET /articles/dang-wo-men-zai-tan-lun-ju-can HTTP/1.1        |      404 | -              |
| GET /articles/jin-nian-zui-hao-kan-de-10ben HTTP/1.1         |      404 | -              |
| GET /articles/pi-gu-da-shi-shi-yao-ti-yan/ HTTP/1.1          |      404 | -              |
| GET /articles/sui-ran-wo-jing-chang-jiao-cuo HTTP/1.1        |      404 | -              |
| GET /articles/xin-dian-gun-muji-yi-zhu-zong HTTP/1.1         |      404 | -              |
| GET /articles/zhong-yu-deng-dao-zhe-bu-shen HTTP/1.1         |      404 | -              |
```


写在最后：
>  可能这个小工具对你并没有神马卵用。 但是，对于在阿里云上购买了一台服务器，又没有神马钱的小伙伴也许有点小帮助吧


[相关文档](https://github.com/lebinh/ngxtop "ngxtop")

ngxtop 使用指南

## ubuntu 14.04 LTS** 默认安装的 nginx 版本是 1.6 由于发布时间比较长可能存在一些漏洞。 

所以，需要升级 nginx 到最新的 1.11。

---

### 首先，到 nginx 官网下载签名**

```.shell
cd /tmp/ && wget http://nginx.org/keys/nginx_signing.key 
sudo apt-key add nginx_signing.key
```

### 然后，添加以下信息

```.shell
    cat > /etc/apt/sources.list.d/nginx.list  
    deb http://nginx.org/packages/mainline/ubuntu/ trusty nginx
    deb-src http://nginx.org/packages/mainline/ubuntu/ trusty nginx
```

### 最后执行

```.shell
sudo aptitude update
sudo aptitude upgrade nginx
```

这样，升级完成了。

---

> tips：  
> 当然，也可以下载个源码包自己编译。  
> 不过个人感觉没什么比较。

Ubuntu 14.04 安装最新版本的 nginx

折腾了好久 apache+wsgi 不知道为什么一直在 memory leak

在失去了改源码的激情中, 只能通过换服务的方式解决了.

借鉴 instagram 的典型架构使用

***django + gunicorn + nginx***  跑 app server 来支撑

安装 django 这里就不多说了....

gunicorn 安装其实也非常简单

懒的去折腾些什么了. 所以,直接用 apt-get 安装

```.bash
aptitude install gunicorn
```

### 配置 gunicorn+django 的启动脚本
```.bash
#!/bin/bash
set -e 
LOGFILE=/tmp/guni.log
LOGDIR=$(dirname $LOGFILE)
NUM_WORKERS=3  # cpu core nums * 2 + 1
USER=nobody
GROUP=nogroup
WORKER=gevent # install python gevent
ADDRESS=127.0.0.1:8000

cd /path/to/project/
test -d $LOGDIR || mkdir -p $LOGDIR
exec gunicorn_django -w $NUM_WORKERS --bind=$ADDRESS \
      -k $WORKER --daemon \
      --user=$USER --group=$GROUP --log-level=error \
      --log-file=$LOGFILE 2>>$LOGFILE
```

这样 gunicorn 就安装完成了.

### 接下来, 整合nginx. 同样,安装也不说了.
```.nginx
    user nobody nogroup;
    worker_processes  8;
    
    #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;
        accept_mutex on;
        use epoll;
    }
    
    
    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;
        tcp_nodelay     on;
    
        keepalive_timeout  5;
    
        gzip on;
        gzip_min_length  1100;
        gzip_buffers     4 32k;
        gzip_types       text/plain application/x-javascript text/xml text/css;
    
        upstream app_server_djangoapp {
            server 127.0.0.1:8000 fail_timeout=5;
        }
    
        server {
            listen       80;
            server_name  _;
    
            root /path/to/project;
    
            location /static/ {
    	    if ($query_string) {
    		expires max;
    #		log_not_found off;
                 }
             }
    
        location / {
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header Host $http_host;
            proxy_redirect off;
    
            if (!-f $request_filename) {
                proxy_pass http://app_server_djangoapp;
                break;
            }
        }
    
            #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;
            }
        }
    }
```

先介绍到这里, 继续 debug.

参考文档: [http://senko.net/en/django-nginx-gunicorn/](http://senko.net/en/django-nginx-gunicorn/ "http://senko.net/en
/django-nginx-gunicorn/" )

解决： Nginx 400 request line is too large (5132 4094)

ngxtop 使用指南

Ubuntu 14.04 安装最新版本的 nginx

django+gunicorn+nginx 配置

GitHub