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。
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';说明：
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 |
$upstream_response_time |
请求过程中，upstream响应时间 |
0.002 |
备注：$http_host的值和你在浏览器里输入的值有关。
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)" |
|
