读取CDN日志数据

背景信息

阿里云内容分发网络（Content Delivery Network，CDN）是建立并覆盖在承载网之上，由分布在不同区域的边缘节点服务器群组成的分布式网络。CDN分担源站压力，避免网络拥塞，确保在不同区域、不同场景下加速网站内容的分发，提高资源访问速度。您可以将CDN日志转存到OSS，或者将CDN日志配置实时日志推送，然后进行日志分析。

前提条件

步骤一：将CDN日志转存到OSS

将CDN日志转存到OSS，如何转存，请参见通过函数计算转存离线日志。

步骤二：创建OSS Schema

假设OSS Bucket中存储了以下CDN日志文件。

您可以在DMS页面编写SQL创建OSS Schema、创建日志文件表以及读取日志文件数据，也可以通过MySQL客户端或者MySQL命令行工具连接DLA，然后编写SQL创建OSS Schema、创建日志文件表以及读取日志文件数据。

​CREATE SCHEMA cdn_log_schema with DBPROPERTIES(
   catalog='oss',
  location = 'oss://bucket-name/cdn/'
  );​

步骤三：创建日志文件表

CDN日志文件数据如下：

[9/Jun/2015:01:58:09 +0800] 188.165.XX.XX - 1542 "-" "GET http://www.aliyun.com/index.html" 200 191 2830 MISS "Mozilla/5.0 (compatible; AhrefsBot/5.0; +http://ahrefs.com/robot/)" "text/html"

日志字段含义如下：

在DLA中建表时，需要采用正则表达式对CDN日志进行解析，每个字段和对应的正则表达式说明如下：

完整的正则表达式为：(-|\\[[^\\]]*\\]) ([^ ]*) ([^ ]*) ([^ ]*) ([^ \"]*|\"[^\"]*\") ([^ \"]*|\"[^\"]*\") (-|[0-9]*) (-|[0-9]*) (-|[0-9]*) ([^ ]*) ([^ \"]*|\"[^\"]*\") ([^ \"]*|\"[^\"]*\")。

DLA中创建日志文件表的SQL语句如下：

​CREATE EXTERNAL TABLE cdn_log (
  log_timestamp           VARCHAR,
  access_ip               VARCHAR,
  proxy_ip                VARCHAR,
  response_time           VARCHAR,
  referer                 VARCHAR,
  request                 VARCHAR,
  httpcode                SMALLINT,
  request_size            BIGINT,
  response_size           BIGINT,
  cache_hit_status        VARCHAR,
  ua_header               VARCHAR,
  file_type               VARCHAR
)
ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.RegexSerDe'
WITH SERDEPROPERTIES (
"input.regex" = "(-|\\[[^\\]]*\\]) ([^ ]*) ([^ ]*) ([^ ]*) ([^ \"]*|\"[^\"]*\") ([^ \"]*|\"[^\"]*\") (-|[0-9]*) (-|[0-9]*) (-|[0-9]*) ([^ ]*) ([^ \"]*|\"[^\"]*\") ([^ \"]*|\"[^\"]*\")"
)
STORED AS TEXTFILE
LOCATION 'oss://bucket-name/cdn/'
TBLPROPERTIES ('recursive.directories' = 'true');​

步骤四：查询、分析CDN日志

SELECT * FROM cdn_log;

返回结果如下：

​+------------------------------+---------------+----------+---------------+---------+----------------------------------+----------+--------------+---------------+------------------+-------------------------------------------------------------+---------------------------+
| log_timestamp                | access_ip     | proxy_ip | response_time | referer | request                          | httpcode | request_size | response_size | cache_hit_status | ua_header                                                   | file_type                 |
+------------------------------+---------------+----------+---------------+---------+----------------------------------+----------+--------------+---------------+------------------+-------------------------------------------------------------+---------------------------+
| [18/Jun/2019:05:08:33 +0800] | 47.92.XX.XX   | -        | 777           | "-"     |                                  |      200 |          201 |          7159 | MISS             | "Mozilla/5.0 (Linux; Android 4.1.1; Nexus 7 Build/JRO03D))" | "text/html;charset=UTF-8" |
+------------------------------+---------------+----------+---------------+---------+----------------------------------+----------+--------------+---------------+------------------+-------------------------------------------------------------+---------------------------+​

您可以使用DLA系统函数，对数据进行分析。

​SELECT date_parse(substring(log_timestamp, 2, length(log_timestamp) - 8), '%d/%b/%Y:%H:%i:%s') as log_timestamp,
       access_ip,
       proxy_ip,
       response_time,
       substring(referer, 2, length(referer) - 2) as referer,
       substring(request, 2, length(request) - 2) as request,
       httpcode,
       request_size,
       response_size,
       cache_hit_status,
       substring(ua_header, 2, length(ua_header) - 2) as ua_header,
       substring(file_type, 2, length(file_type) - 2) as file_type 
FROM cdn_log;

+-------------------------+---------------+----------+---------------+---------+--------------------------------+----------+--------------+---------------+------------------+-----------------------------------------------------------+-------------------------+
| log_timestamp           | access_ip     | proxy_ip | response_time | referer | request                        | httpcode | request_size | response_size | cache_hit_status | ua_header                                                 | file_type               |
+-------------------------+---------------+----------+---------------+---------+--------------------------------+----------+--------------+---------------+------------------+-----------------------------------------------------------+-------------------------+
| 2019-06-18 05:08:33.000 | 47.92.XX.XX   | -        | 777           | -       |                                |      200 |          201 |          7159 | MISS             | Mozilla/5.0 (Linux; Android 4.1.1; Nexus 7 Build/JRO03D)) | text/html;charset=UTF-8 |
+-------------------------+---------------+----------+---------------+---------+--------------------------------+----------+--------------+---------------+------------------+-----------------------------------------------------------+-------------------------+​