有一天突发奇想，nginx反向代理能不能记录后端接口的处理时间呢？如果能记录那么就可用定位分析接口的处理异常了。
配置
如果需要nginx记录请求时间，那么就需要配置nginx的log_fromat
具体修改nginx.conf配置文件
http {
include /etc/nginx/conf/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 $request_time $upstream_response_time $upstream_addr $upstream_status';
log_format apm '[$time_local]\tclient=$remote_addr\t'
'request="$request"\t request_length=$request_length\t'
'http_referer="$http_referer"\t'
'bytes_sent=$bytes_sent\t'
'body_bytes_sent=$body_bytes_sent\t'
'user_agent="$http_user_agent"\t'
'upstream_addr=$upstream_addr\t'
'upstream_status=$upstream_status\t'
'cookie="$http_cookie"\t'
'request_body="$request_body"\t'
'document_root="$document_root"\t'
'fastcgi_script_name="$fastcgi_script_name"\t'
'request_filename="$request_filename"\t'
'request_time=$request_time\t'
'upstream_response_time=$upstream_response_time\t'
'upstream_connect_time=$upstream_connect_time\t'
'upstream_header_time=$upstream_header_time\t';
# 为什么有的变量有双引号，有的没有呢？
# 如果变量结果是数字的，就不需要双引号，变量是字符的，就需要双引号
access_log /var/log/nginx/access.log main;
error_log /var/log/nginx/error.log crit;
上面配置了两个log_format，设置两个log_format的目的是为了让不同的后端的服务，使用不用日志格式。
如果后端的server没有配置，就默认使用main 标记的日志，
access_log /var/log/nginx/access.log main; # 这里配置的
如果需要apm格式，只需要在access_log配置apm即可
server {
listen 8000;
server_name www.test.com;
location / {
proxy_pass http://192.168.1.80:8080;
# 这里设置apm即可使用apm格式的log_format
access_log /var/log/nginx/getip-access.log apm;
include /conf.d/proxy-params.conf;
}
}
结果验证
请求 www.test.com
输出日志结果为：
[11/May/2020:11:22:20 +0800]
client=192.168.1.100
request="GET / HTTP/1.1"
request_length=452
http_referer="-"
bytes_sent=170
body_bytes_sent=14
user_agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.163 Safari/537.36"
upstream_addr=192.168.1.80:8080
upstream_status=200
cookie="-"
request_body="-"
document_root="/etc/nginx/html"
fastcgi_script_name="/"
request_filename="/etc/nginx/html/"
request_time=5.006
upstream_response_time=5.006
upstream_connect_time=0.000
upstream_header_time=5.006
下面为proxy_pass http://192.168.1.80:8080; 接口处理时间，
upstream_response_time=5.006
upstream_connect_time=0.000
upstream_header_time=5.006
因为我在后端服务器配置了sleep 5秒，因此处理时间为5秒多，这个时间就反应了
用户发送一次请求，到nginx代理后端服务器，再从后端服务器处理完毕，反馈给用户的时间
记录了一次完整的请求时间
后续可以从日志中提取时间，分析网页中哪个接口请求比较慢
后端服务www.test.com的代码
#!/bin/python
# -*- coding: UTF-8 -*-
from flask import Flask, render_template, request
import time
# Initialize the Flask application
app = Flask(__name__)
@app.route('/')
def index():
user_ip = None
if 'X-Real-Ip' in request.headers.keys():
user_ip = request.headers['X-Real-Ip']
else:
user_ip = request.remote_addr
time.sleep(5)
return user_ip
if __name__ == '__main__':
app.run(host="0.0.0.0",port=int("5000"))
后续
这个访问日志格式还可以优化，还可以定制不同的参数，设置为json格式等等。
log_format main '{
"remote_addr":"$remote_addr",
"remote_user":"$remote_user",
"time_local":"$time_local",
"request":"$request",
"status":"$status",
"request_time":"$request_time",
"upstream_response_time":"$upstream_response_time",
"request_length":"$request_length",
"bytes_sent":"$bytes_sent",
"body_bytes_sent":"$body_bytes_sent",
"gzip_ratio":"$gzip_ratio",
"connection_requests":"$connection_requests",
"http_referer":"$http_referer",
"http_user_agent":"$http_user_agent",
"http_x_forwarded_for":"$http_x_forwarded_for"
}';
log_format main '{
"remote_addr":"$remote_addr",
"upstream_addr":"$upstream_addr",
"status":"$status",
"upstream_status":"$upstream_status",
"http_referer":"$http_referer",
"http_user_agent":"$http_user_agent",
"http_x_forwarded_for":"$http_x_forwarded_for"
"remote_user":"$remote_user",
"request_body":"$request_body",
"document_root":"$document_root",
"fastcgi_script_name":"$fastcgi_script_name",
"request_filename":"$request_filename",
"request":"$request",
"request_length":"$request_length",
"bytes_sent":"$bytes_sent",
"body_bytes_sent":"$body_bytes_sent",
"gzip_ratio":"$gzip_ratio",
"connection_requests":"$connection_requests",
"time_local":"$time_local",
"request_time":"$request_time",
"upstream_response_time":"$upstream_response_time",
"upstream_connect_time":"$upstream_connect_time",
"upstream_header_time":"$upstream_header_time",
}';
format变量说明
$remote_addr #发起请求的客户端所在ip地址
$remote_user #发起请求的客户端用户名称，获取不到则显示为 -
$time_local #用来记录访问时间与时区(依赖nginx服务器本地时间)，形如 20/Aug/2017:21:15:19 +0800，获取不到则显示为 -
$time_iso8601 #类似$time_local，不同的是这里采用ISO 8601标准格式
$request #记录发起的请求，形如 POST /zentaopms/www/index.php?m=user&f=login&referer=L3plbnRhb3Btcy93d3cvaW5kZXgucGhw HTTP/1.1
$status #记录响应状态，比如 200
$request_time
#记录请求处理时间（以秒为单位，携带毫秒的解决方案），
#从读取客户端第一个字节开始算起，到发送最后一个字节给客户端的时间间隔
#（原文：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）
$upstream_response_time #记录nginx从后端服务器(upstream server)获取响应的时间（以秒为单位，携带毫秒的解决方案），多个请求的时间以逗号分隔
$request_length #记录请求长度(包括请求行，请求头，请求体)
$gzip_ratio #记录nginx gzip压缩比例，获取不到则显示为 -
$bytes_sent #发送给客户端的字节数
$body_bytes_sent #发送给客户端的响应体字节数
$connection_requests #单个连接的并发请求数（the current number of requests made through a connection (1.1.18)
$http_referer #记录请求引用页面地址
$http_user_agent #记录用户代理信息（通常是浏览器信息
$http_x_forwarded_for
#当为了承受更大的负载使用反向代理时，web服务器不能获取真实的客户端IP，
#$remote_addr获取到的是反向代理服务器的ip，
#这种情况下，代理服务器通常会增加一个叫做x_forwarded_for的信息头，
#把连接它的真实客户端IP加到这个信息头里，这样就能保证网站的web服务器能获取到真实IP，获取不到则显示为 -
$connection #连接序列号
$msec #写入日志的时间（以秒为单位，携带毫秒的解决方案）(原文：time in seconds with a milliseconds resolution at the time of the log write)
$pipe #如果为管道请求则显示为p，否则显示为 .
参考链接：
# http://nginx.org/en/docs/http/ngx_http_upstream_module.html#var_upstream_response_time
附上 nginx可用的参数大全
https://nginx.org/en/docs/http/ngx_http_core_module.html#var_status
参考链接：
https://www.cnblogs.com/kevingrace/p/5893499.html
https://www.cnblogs.com/shouke/p/10157556.html
http://www.ttlsa.com/linux/the-nginx-log-configuration/
https://www.cnblogs.com/taoshihan/p/11978842.html
https://blog.csdn.net/ronon77/article/details/84732095
https://www.baidu.com/s?ie=UTF-8&wd=ngx_http_log_request_speed