海量CDN日志高性价比分析方案

概述

CDN产生大量日志，可以进行日志转存（https://help.aliyun.com/document_detail/88894.html）到OSS bucket中。也可以进行实时日志推送（https://help.aliyun.com/document_detail/121169.html），推送到日志服务SLS中进行实时分析，也可以在日志服务SLS中配置OSS日志投递，将海量CDN日志长期保存在OSS中。在OSS中的海量CDN日志，利用Data Lake Analytics进行分析。

CDN日志到日志服务的实时日志推送可以参考：https://help.aliyun.com/document_detail/121169.html
日志服务投递OSS链路和DLA的OSS日志分析可以参考：https://yq.aliyun.com/articles/705888

假设CDN的原始日志（不是进过日志服务投递OSS链路投递到OSS的，如果是日志服务投递到OSS的，请参考https://yq.aliyun.com/articles/705888），通过转存、上传，直接上传到OSS，文本下面部分介绍在DLA中建表分析的步骤。

步骤一：针对OSS上CDN日志建表

假设您已经将CDN日志传到OSS上，每行日志如下示例：

[9/Jun/2015:01:58:09 +0800] 188.165.15.75 - 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"

其中每个字段含义为：

在DLA中建表，采用正则表达式的方式对CDN日志进行解析，正则表达式是对上述字段进行分别识别，每个字段和对应的正则表达式片段为：

为方便您复制粘贴，上述对应字段的样例和对应的正则表达式片段对应如下：

[9/Jun/2015:01:58:09 +0800] 
-> (-|\\[[^\\]]*\\])

188.165.15.75
-> ([^ ]*)

-
-> ([^ ]*) 

1542 
-> ([^ ]*)

"-"
-> ([^ \"]*|\"[^\"]*\")

"GET http://www.aliyun.com/index.html"
-> ([^ \"]*|\"[^\"]*\")

200 
-> (-|[0-9]*) 

191 
-> (-|[0-9]*)

2830
-> (-|[0-9]*)

MISS
-> ([^ ]*)

"Mozilla/5.0 (compatible; AhrefsBot/5.0; +http://ahrefs.com/robot/)"
-> ([^ \"]*|\"[^\"]*\")

"text/html"
-> ([^ \"]*|\"[^\"]*\")

当然，上述字段的顺序可能根据实际情况有些变化，不过没有关系，可以根据上述字段对应正则进行顺序调整组合。

对于上述样例日志，对应的正则表达式为：

(-|\\[[^\\]]*\\]) ([^ ]*) ([^ ]*) ([^ ]*) ([^ \"]*|\"[^\"]*\") ([^ \"]*|\"[^\"]*\") (-|[0-9]*) (-|[0-9]*) (-|[0-9]*) ([^ ]*) ([^ \"]*|\"[^\"]*\") ([^ \"]*|\"[^\"]*\")

假设在OSS上，存储的CDN日志目录为：
oss://your_cdn_log_bucket/log/

则在DLA中建表：

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://your_cdn_log_bucket/log/'
TBLPROPERTIES ('recursive.directories' = 'true');

上述建表为非分区表，如果在OSS日志数据存储为分区模式，可以对应修改为分区表模式，关于分区，可以参考：https://yq.aliyun.com/articles/705888 中的“步骤四”和“步骤五”。

步骤二：查询、分析CDN日志

SELECT * 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                 |
+------------------------------+---------------+----------+---------------+---------+----------------------------------+----------+--------------+---------------+------------------+-------------------------------------------------------------+---------------------------+
| [18/Jun/2019:05:08:33 +0800] | 47.92.115.203 | -        | 777           | "-"     | "GET http://www.kalabandha.com/" |      200 |          201 |          7159 | MISS             | "Mozilla/5.0 (Linux; Android 4.1.1; Nexus 7 Build/JRO03D))" | "text/html;charset=UTF-8" |
+------------------------------+---------------+----------+---------------+---------+----------------------------------+----------+--------------+---------------+------------------+-------------------------------------------------------------+---------------------------+

可以利用DLA的系统函数，对数据字段进行分析：https://help.aliyun.com/document_detail/71065.html

例如：

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 | 47.92.115.203 | -        | 777           | -       | GET http://www.kalabandha.com/ |      200 |          201 |          7159 | MISS             | Mozilla/5.0 (Linux; Android 4.1.1; Nexus 7 Build/JRO03D)) | text/html;charset=UTF-8 |
+-------------------------+---------------+----------+---------------+---------+--------------------------------+----------+--------------+---------------+------------------+-----------------------------------------------------------+-------------------------+