前言：
Nginx日志里面Mobileweb_access.log增长特别大，一天上百兆，将近100W的访问记录，按照我们目前的规模，热点用户才500个左右，就算人人用手机app访问，怎么可能会有这么大的url访问量？以前只是安装使用nginx，还没有抽出时间仔细研究，这回需要彻底的去分析nginx日志了。
1，日志分类
主要2种，一种是错误日志，一种是访问日志，这些配置都在/usr/local/nginx/conf/nginx.conf里面，默认都是打开的，自己也可以选择关闭。
1.1，访问日志
访问日志主要记录每一个访问nginx的请求，格式可以自己定义，在nginx.conf文件里面，通过访问日志，你可以看到每一个请求的详细信息，对于访问日志的格式，主要是配置文件中的log_format来限制的。
1.1.1 log_format日志格式
$request_time：整个请求的总时间。
$time_iso8601：访问的时间与时区，比如18/Jul/2012:17:00:01 +0800，时间信息最后的"+0800"表示服务器所处时区位于UTC之后的8小时。
$upstream_response_time：请求过程中，upstream的响应时间。
$request_method：客户端请求的动作，通常为GET或POST。
$request_uri：是浏览器发过来的值。该值是rewrite后的值。例如做了internal
redirects后。
$args：这个变量等于请求行中(GET请求)的参数，例如foo=123&bar=blahblah;
$query_string：与$args相同。
$proxy_add_x_forwarded_for：变量包含客户端请求头中的"X-Forwarded-For"，与$remote_addr用逗号分开，如果没有"X-Forwarded-For" 请求头，则$proxy_add_x_forwarded_for等于$remote_addr。
$upstream_addr：upstream的地址，即真正提供服务的主机地址。
$status：记录请求返回的http状态码，比如成功是200。
$http_user_agent：客户端浏览器信息
$http_range
$sent_http_content_length：发送内容的长度
$body_bytes_sent：发送给客户端的文件主体内容的大小，比如899，可以将日志每条记录中的这个值累加起来以粗略估计服务器吞吐量。
$http_referer：记录从哪个页面链接访问过来的。
$host：请求主机头字段，否则为服务器名称。
$http_x_forwarded_for：客户端的真实ip，通常web服务器放在反向代理的后面，这样就不能获取到客户的IP地址了，通过$remote_add拿到的IP地址是反向代理服务器的iP地址。反向代理服务器在转发请求的http头信息中，可以增加x_forwarded_for信息，用以记录原有客户端的IP地址和原来客户端的请求的服务器地址。
$http_user_agent：客户端浏览器信息
$body_bytes_sent：发送给客户端的文件主体内容的大小，比如899，可以将日志每条记录中的这个值累加起来以粗略估计服务器吞吐量。
$ssl_protocol：SSL协议版本，比如TLSv1。
$ssl_cipher：交换数据中的算法，比如RC4-SHA。
生产环境上的范例：
log_format main '$proxy_add_x_forwarded_for $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for" '
'upsteam: $upstream_addr';
access_log logs/access.log main;
log_not_found off;
1.1.2，访问日志路径
access_log logs/access.log main;
Nginx支持为每个location指定强大的日志记录。同样的连接可以在同一时间输出到不止一个的日志中。如果想关闭日志，可以如下：
access_log off;
能够使用access_log指令的字段包括：http、server、location。
PS：Nginx进程设置的用户和组必须对日志路径有创建文件的权限，否则，会报错。
错误日志主要记录客户端访问Nginx出错时的日志，格式不支持自定义。通过错误日志，你可以得到系统某个服务或server的性能瓶颈等。因此，将日志好好利用，你可以得到很多有价值的信息。错误日志由指令error_log来指定，具体格式如下：
error_log path(存放路径) level(日志等级)
path含义同access_log，level表示日志等级，具体如下：
[ debug | info | notice | warn | error | crit ]
从左至右，日志详细程度逐级递减，即debug最详细，crit最少，举例说明如下：
error_log logs/mobileweb_error.log error;
需要注意的是：error_log off并不能关闭错误日志，而是会将错误日志记录到一个文件名为off的文件中。正确的关闭错误日志记录功能的方法如下：
error_log /dev/null;
上面表示将存储日志的路径设置为“垃圾桶”。
2，为每一个工程定义特定的日志
location ~* ^/mobileWeb/.*$ {
client_max_body_size 5m;
include deny.conf;
proxy_pass http://mobilewebbackend;
include proxy.conf;
error_log logs/mobileweb_error.log error;
access_log logs/mobileweb_access.log main;
include gzip.conf;
}
这样，就会在日志路径/usr/local/nginx/logs/下面生成mobileWeb工程的专门日志mobileweb_error.log 以及mobileweb_access.log 日志，如果想查询mobileWeb工程的访问记录，就可以单独去查看这2个日志。
3，开始分析
根据来源ip进行分组统计分析，看看哪个ip的访问量最多
[root@wgq_idc_web_1_21 tmp]# cat mobileweb_access.log |grep "14/Oct/2014" |awk '{print $1}'|sort -nr |uniq -c |sort -nr |more
705980 1xx.xx.xx.185,
190273 6x.1x4.1xx.35,
14900 1xx.xxx.xx.xx3,
14670 1xx.xxx.x3.8x,
结果发现，这几个ip都是我们公司广场公用的wifi出口ip地址，属于安全地址，不是私人的IP地址，很大程度上排除了从外部恶意攻击我们网站的可能性。接下来就需要重点分析，为什么会有这么多的URL记录。
仔细排查来源为1xx.xx.xx.185的日志记录，发现有很多$http_user_agent为空的记录，大概90%的记录都是如此，看记录如下：
1xx.xx.xx.185, 10.2xx.xx1.xx0 - [10/Oct/2014:10:52:11 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "1xx.xx.xx.185"upsteam: 110.xx7.1.22:7100
猜测是否不是手机app访问的记录？只有自己停掉wifi，用手机的4G网络，去登录我们的移动app应用，操作完，点击了几下赞，访问了一些页面，操作时间2分钟，然后使用自己的移动4Gip地址“2xx.10x.5.129”去检索下nginx下的mobileweb的记录，4台nginx记录，每一台40个左右url访问，4台就是160个记录，下面是一台的记录
[root@wgq_idc_web_1_22 logs]# more mobileweb_access.log |grep "2xx.10x.5.129"
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:01 +0800] "POST /mobileWeb/userMobileCenter/queryUserNameAndIconByIds.htm? HTTP/1.1" 200 20 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:37 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:42 +0800] "POST /mobileWeb/square/query.htm? HTTP/1.1" 200 9485 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:42 +0800] "POST /mobileWeb/square/query.htm? HTTP/1.1" 200 9485 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:49 +0800] "POST /mobileWeb/square/clickSupport.htm? HTTP/1.1" 200 46 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:51 +0800] "POST /mobileWeb/square/clickSupport.htm? HTTP/1.1" 200 46 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:54 +0800] "POST /mobileWeb/square/clickSupport.htm? HTTP/1.1" 200 46 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:55 +0800] "POST /mobileWeb/square/query.htm? HTTP/1.1" 200 4831 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:54:57 +0800] "POST /mobileWeb/userMobileCenter/queryUserNameAndIconByIds.htm? HTTP/1.1" 200 20 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:03 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:04 +0800] "POST /mobileWeb/version/queryVersion.htm? HTTP/1.1" 200 160 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:06 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:06 +0800] "POST /mobileWeb/mobile/loadCart.htm? HTTP/1.1" 200 940 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:07 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:07 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:07 +0800] "POST /mobileWeb/userMobileCenter/findAllinterfaceVersion.htm? HTTP/1.1" 200 411 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:13 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:56 +0800] "POST /mobileWeb/userMobileCenter/queryUserNameAndIconByIds.htm? HTTP/1.1" 200 20 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:57 +0800] "POST /mobileWeb/userMobileCenter/findAllinterfaceVersion.htm? HTTP/1.1" 200 411 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:58 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:58 +0800] "POST /mobileWeb/version/queryVersion.htm? HTTP/1.1" 200 160 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:55:59 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:00 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:06 +0800] "POST /mobileWeb/userMobileCenter/findAllinterfaceVersion.htm? HTTP/1.1" 200 411 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:07 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:07 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:08 +0800] "POST /mobileWeb/version/queryVersion.htm? HTTP/1.1" 200 160 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:08 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:08 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:16 +0800] "POST /mobileWeb/userMobileCenter/queryUserNameAndIconByIds.htm? HTTP/1.1" 200 20 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:19 +0800] "POST /mobileWeb/userMobileCenter/findAllinterfaceVersion.htm? HTTP/1.1" 200 411 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:21 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:21 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:23 +0800] "POST /mobileWeb/userMobileCenter/queryUserNameAndIconByIds.htm? HTTP/1.1" 200 20 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:23 +0800] "POST /mobileWeb/userMobileCenter/findAllinterfaceVersion.htm? HTTP/1.1" 200 411 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:24 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:24 +0800] "POST /mobileWeb/userMobileCenter/queryAdvertisement.htm? HTTP/1.1" 200 5175 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:24 +0800] "POST /mobileWeb/version/queryVersion.htm? HTTP/1.1" 200 160 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:25 +0800] "POST /mobileWeb/userMobileCenter/unReadNumsMobile.htm? HTTP/1.1" 200 239 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:56:25 +0800] "POST /mobileWeb/mobile/getCartItemNum.htm? HTTP/1.1" 200 114 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:14:57:37 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:00:37 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:02:07 +0800] "POST /mobileWeb/userMobileCenter/messageListMobile.htm? HTTP/1.1" 200 106 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:02:08 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:02:37 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:05:07 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:05:08 +0800] "POST /mobileWeb/push/query.htm? HTTP/1.1" 200 97 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:05:37 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.21:7100
2xx.10x.5.129, 10.2xx.xx1.xx0 - [16/Oct/2014:15:11:44 +0800] "POST /mobileWeb/square/queryCounts.htm? HTTP/1.1" 200 82 "-" "-" "2xx.10x.5.129"upsteam: 110.xx7.1.22:7100
[root@wgq_idc_web_1_22 logs]#
看到了我的访问url记录，其中$http_user_agent几乎都是为”-”空记录，奇怪，我也是用手机访问的，询问andriod开发人员，他说有些低版本的手机在记录$http_user_agent后退回去会报错返回空界面，所以后来就不记录$http_user_agent信息了。
原来如此，而且看到这么多url全是我访问过的，移动mobileweb后台开发人员说，移动app一个页面里面有许多url需要加载，所以你访问1个页面就会加载N个link连接去取各种数据值。分析道这里，已经差不多明了：就是一个登录用户访问页面，会加载N（N>10）个link连接url，这些url都被记录在nginx访问日志里面，短短2分钟内，我访问了一些页面，就有160个左右的记录，照这么算下来，一个小时就是5000个左右的记录，一天平均25分钟分钟，500个用户个就是SELECT
5000*25/60*500=1041667，差不多100W左右了，通常来说nginx日志的量比较大是正常的。
其中，半夜1点到6点左右，这个公司广场wifi的ip地址还会不停的访问mobileweb，经过分析是由于登录了移动app应用，但是睡觉了没有退出应用，手机也没有关系，所以导致移动app依然不停的在访问mobile应用（因为1分钟左右会刷新一次去获取访问当前登录用户的站内互动消息）。
从此可以看出nginx的访问日志记录了用户的所有访问行为记录，而且详细到每一个页面里内嵌的url记录，如果用适当的工具仔细分析nginx日志，就会大概摸清楚用户的访问习惯，这些数据对于市场部门、产品部门来说，是非常有价值的。