1、日志简介

nginx日志主要有两种：访问日志和错误日志。访问日志主要记录客户端访问nginx的每一个请求，格式可以自定义；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。两种日志都可以选择性关闭。

通过访问日志，你可以得到用户地域来源、跳转来源、使用终端、某个URL访问量等相关信息；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。

2、访问日志

[Access.log]

log_format  main  '$remote_addr $remote_user [$time_local] "$request" $http_host '

                  '$status $upstream_status $body_bytes_sent "$http_referer" '

                  '"$http_user_agent" $ssl_protocol $ssl_cipher $upstream_addr '

                  '$request_time $upstream_response_time'; 

变量名称

变量描述

举例说明

$remote_addr

客户端地址

113.140.15.90

$remote_user

客户端用户名称

-

$time_local

访问时间和时区

18/Jul/2012:17:00:01 +0800

$request

请求的URI和HTTP协议

"GET /pa/img/home/logo-alipay-t.png HTTP/1.1"

$http_host

请求地址，即浏览器中你输入的地址（IP或域名）

img.alipay.com

10.253.70.103

$status

HTTP请求状态

200

$upstream_status

upstream状态

200

$body_bytes_sent

发送给客户端文件内容大小

547

$http_referer

跳转来源

 "https://cashier.alipay.com.../"

$http_user_agent

用户终端代理

"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; SV1; GTB7.0; .NET4.0C;

$ssl_protocol

SSL协议版本

TLSv1

$ssl_cipher

交换数据中的算法

RC4-SHA

$upstream_addr

后台upstream的地址，即真正提供服务的主机地址

10.228.35.247:80

$request_time

整个请求的总时间

0.205

$upstream_response_time

请求过程中，upstream响应时间

0.002

线上实例：

116.9.137.90 - [02/Aug/2012:14:47:12 +0800] "GET /p_w_picpaths/XX/20100324752729.png HTTP/1.1"img.alipay.com 200 200 2038 https://cashier.alipay.com/XX/PaymentResult.htm?payNo=XX&outBizNo=2012XX "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; Tablet PC 2.0; 360SE)" TLSv1 AES128-SHA 10.228.21.237:80 0.198 0.001

 

线下测试（$http_referer）：

10.14.21.197 - - [14/Aug/2012:17:28:22 +0800] "GET /spanner/watch/v1?--db=ztg-1&--mode=compare&--index=status&--option=&--cluster=whole&-F=2012%2F8%2F12-00%3A00%3A00&-T=%2B2880&-i=1&-n=0&_=1344936501292 HTTP/1.1" 200 94193 "http://spanner.alipay.net/optionFrame/history.html" "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.60 Safari/537.1"



 wKioL1OIQJGA0wsBAACXQzKS7MU162.jpg

备注：$http_referer和重定向有关。

线下测试（$http_host）：

wKiom1OIQPXC0DSuAABdsxpBYxQ642.jpg

备注：$http_host的值和你在浏览器里输入的值有关。

3、错误日志

错误信息

错误说明

"upstream prematurely（过早的） closed connection"

请求uri的时候出现的异常，是由于upstream还未返回应答给用户时用户断掉连接造成的，对系统没有影响，可以忽略

"recv() failed (104: Connection reset by peer)"

（1）服务器的并发连接数超过了其承载量，服务器会将其中一些连接Down掉； 

（2）客户关掉了浏览器，而服务器还在给客户端发送数据； 

（3）浏览器端按了Stop

"(111: Connection refused) while connecting to upstream"

用户在连接时，若遇到后端upstream挂掉或者不通，会收到该错误

"(111: Connection refused) while reading response header from upstream"

用户在连接成功后读取数据时，若遇到后端upstream挂掉或者不通，会收到该错误

"(111: Connection refused) while sending request to upstream"

Nginx和upstream连接成功后发送数据时，若遇到后端upstream挂掉或者不通，会收到该错误

"(110: Connection timed out) while connecting to upstream"

nginx连接后面的upstream时超时

"(110: Connection timed out) while reading upstream"

nginx读取来自upstream的响应时超时

 

"(110: Connection timed out) while reading response header from upstream"

nginx读取来自upstream的响应头时超时

"(110: Connection timed out) while reading upstream"

nginx读取来自upstream的响应时超时

"(104: Connection reset by peer) while connecting to upstream"

upstream发送了RST，将连接重置

"upstream sent invalid header while reading response header from upstream"

upstream发送的响应头无效

"upstream sent no valid HTTP/1.0 header while reading response header from upstream"

upstream发送的响应头无效

"client intended to send too large body"

用于设置允许接受的客户端请求内容的最大值，默认值是1M，client发送的body超过了设置值

"reopening logs"

用户发送kill  -USR1命令

"gracefully shutting down",

用户发送kill  -WINCH命令

"no servers are inside upstream"

upstream下未配置server

"no live upstreams while connecting to upstream"

upstream下的server全都挂了

"SSL_do_handshake() failed"

SSL握手失败

"SSL_write() failed (SSL:) while sending to client"

"(13: Permission denied) while reading upstream"

"(98: Address already in use) while connecting to upstream"

"(99: Cannot assign requested address) while connecting to upstream"

"ngx_slab_alloc() failed: no memory in SSL session shared cache"

ssl_session_cache大小不够等原因造成

"could not add new SSL session to the session cache while SSL handshaking"

ssl_session_cache大小不够等原因造成

"send() failed (111: Connection refused)"