在互联网企业中，日志分析是特别重要的一个模块。通过对日志的分析，可以获得网站的一些指标信息，和网站访问情况。另外，日志对于统计排错来说非常有利的。
nginx日志相关的配置如access_log、log_format、open_log_file_cache、log_not_found、log_subrequest、rewrite_log、error_log。
日志相关的配置参数
1.access_log指令
1.1语法
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Syntax:access_log path [
format
[buffer=size] [
gzip
[=level]] [flush=
time
] [
if
=condition]];
access_log off;
Default:access_log logs
/access
.log combined;
Context:http, server, location,
if
in
location, limit_except
默认值: access_log logs
/access
.log combined;
配置段: http, server, location,
if
in
location, limit_except
gzip
压缩等级。
buffer设置内存缓存区大小。
flush保存在缓存区中的最长时间。
不记录日志：access_log off;
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1.2 例子
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access_log
/path/to/log
.gz combined
gzip
flush=5m;
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2. log_format指令
2.1语法
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Syntax: log_format name string ...;
Default:
log_format combined
"..."
;
Context: http
name表示格式名称，string表示等义的格式。
log_format有一个默认的无需设置的combined日志格式，相当于apache的combined日志格式。
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2.2 例子
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log_format combined
'$remote_addr - $remote_user [$time_local] '
'"$request" $status $body_bytes_sent '
'"$http_referer" "$http_user_agent"'
;
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$bytes_sent
the number of bytes sent to a client
$connection
connection serial number
$connection_requests
the current number of requests made through a connection (1.1.18)
$msec
time in seconds with a milliseconds resolution at the time of the log write
$pipe
“p” if request was pipelined, “.” otherwise
$request_length
request length (including request line, header, and request body)
$request_time
request processing time in seconds with a milliseconds resolution; time elapsed between the first bytes were read from the client and the log write after the last bytes were sent to the client
$status
response status
$time_iso8601
local time in the ISO 8601 standard format
$time_local
local time in the Common Log Format
3. open_log_file_cache指令
3.1 语法
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Syntax:open_log_file_cache max=N [inactive=
time
] [min_uses=N] [valid=
time
];
open_log_file_cache off;
Default:open_log_file_cache off;
Context:http, server, location
对于每一条日志记录，都将是先打开文件，再写入日志，然后关闭。可以使用open_log_file_cache来设置日志文件缓存(默认是off)，格式如下：
参数注释如下：
max:设置缓存中的最大文件描述符数量，如果缓存被占满，采用LRU算法将描述符关闭。
inactive:设置存活时间，默认是10s
min_uses:设置在inactive时间段内，日志文件最少使用多少次后，该日志文件描述符记入缓存中，默认是1次
valid:设置检查频率，默认60s
off：禁用缓存
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3.2 例子
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open_log_file_cache max=1000 inactive=20s valid=1m min_uses=2;
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4. log_not_found指令
4.1 语法
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Syntax:log_not_found on | off;
Default:log_not_found on;
Context:http, server, location
是否在error_log中记录不存在的错误。默认是。
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5. log_subrequest指令
语法: log_subrequest on | off;
默认值: log_subrequest off;
配置段: http, server, location
是否在access_log中记录子请求的访问日志。默认不记录。
6. rewrite_log指令
由ngx_http_rewrite_module模块提供的。用来记录重写日志的。对于调试重写规则建议开启。 Nginx重写规则指南
语法: rewrite_log on | off;
默认值: rewrite_log off;
配置段: http, server, location, if
启用时将在error log中记录notice级别的重写日志。
7. error_log指令
Syntax: error_log file [level];
Default:
error_log logs/error.log error;
Context: main, http, mail, stream, server, location
语法: error_log file | stderr | syslog:server=address[,parameter=value] [debug | info | notice | warn | error | crit | alert | emerg];
默认值: error_log logs/error.log error;
配置段: main, http, server, location
配置错误日志。
nginx配置文件如下
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http {
include mime.types;
default_type application
/octet-stream
;
log_format main
'$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;
server {
# 监听的IP和端口
listen 192.168.163.146:80;
server_name server1.domain.com;
access_log logs
/server1
.access.log main;
location /
{
index index.html index.htm;
#存放目录
root
/u01/up1
;
}
}
}
cat
/usr/local/nginx-1
.7.9
/logs/server1
.access.log
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192.168.163.1 - - [29
/Aug/2016
:14:32:00 +0800]
"GET / HTTP/1.1"
200 134
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
192.168.163.1 - - [29
/Aug/2016
:14:32:01 +0800]
"GET / HTTP/1.1"
200 134
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
192.168.163.1 - - [29
/Aug/2016
:14:32:01 +0800]
"GET / HTTP/1.1"
200 134
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
...
192.168.163.1 - - [29
/Aug/2016
:14:32:03 +0800]
"GET / HTTP/1.1"
200 134
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
192.168.163.1 - - [29
/Aug/2016
:14:32:04 +0800]
"GET / HTTP/1.1"
200 134
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
192.168.163.1 - - [29
/Aug/2016
:14:32:41 +0800]
"GET /index.html HTTP/1.1"
200 134
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
192.168.163.1 - - [29
/Aug/2016
:14:32:48 +0800]
"GET /index2html HTTP/1.1"
404 168
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
192.168.163.1 - - [29
/Aug/2016
:14:32:51 +0800]
"GET /index2.html HTTP/1.1"
404 168
"-"
"Mozilla/5.0 (Windows NT 6.1; WOW64; rv:48.0) Gecko/20100101 Firefox/48.0"
"-"
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整体来说，日志配置非常简单。接下来完成日志切割。
为什么要进行日志切割？
我等苦逼程序员，都有过解决线上BUG的经验吧。如果一个日志文件过大，无论从维护或查看角度来说，都不方便。所以要将日志进行切割，而按日切割是最常见的一种方式。这有点像log4j中的某个appender[org.apache.log4j.DailyRollingFileAppender].
按日切割逻辑很简单。主要分3步。
-
备份日志到新文件
-
重新启动nginx
-
将命令加入cron调度
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#!/bin/bash
log_path=
"/usr/local/nginx-1.7.9/logs/"
pid_path=
"/usr/local/nginx-1.7.9/conf/nginx.pid"
mkdir
-p ${log_path}$(
date
-d
"yesterday"
+
"%Y"
)/$(
date
-d
"yesterday"
+
"%m"
)/
mv
${log_path}server1.access.log ${log_path}$(
date
-d
"yesterday"
+%Y)/$(
date
-d
"yesterday"
+%m)
/server1
.access_$(
date
-d
"yesterday"
+%Y%m%d).log
kill
-USR1 `
cat
${pid_path}`
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笔者对linux不经常写，平时也就是简单玩玩。写上面代码也是参照了网上或书中的例子。结果充满坎坷。
1.由于我使用WINSCP工具原因，在本地使用sublime工具开发，结果出现错误
shell /bin/bash^M: bad interpreter错误解决
2.中间错误将$(date -d "yesterday" +"%Y" 写成 ${date -d "yesterday" +"%Y"}
3.将kill -USR1 错误写成“kill -USER1”
Nginx控制信号
TERM， INT
快速关闭
QUIT
从容关闭
HUP
重新加载，用新的配置开始新的工作进程
USER1
重新打开日志文件
USER2
平滑升级可执行程序
WINCH
从容关闭工作进程
()会开启一个新的子shell，{}不会开启一个新的子shell
(())常用于算术运算比较,[[]]常用于字符串的比较.
$()返回括号中命令执行的结果
$(())返回的结果是括号中表达式值
${ }参数替换与扩展
本文转自 randy_shandong 51CTO博客，原文链接：http://blog.51cto.com/dba10g/1843959，如需转载请自行联系原作者
