在学习开源监控prometheus和grafana的时候，通过nginx代理无法访问grafana问题记录。在调整grafana的ini文件后，直连grafana是没问题，通过nginx代理访问页面报错如下。
If you’re seeing this Grafana has failed to load its application files

1. This could be caused by your reverse proxy settings.
2. If you host grafana under subpath make sure your grafana.ini root_url setting includes subpath. If not using a reverse proxy make sure to set serve_from_sub_path to true.
3. If you have a local dev build make sure you build frontend using: yarn start, yarn start:hot, or yarn build
4. Sometimes restarting grafana-server can help
5. Check if you are using a non-supported browser. For more information, refer to the list of supported browsers.

参考

Prometheus、Grafana安装-部署-nginx代理-监控linux
解决Nginx遇到206问题
Nginx时js加载报206 (Partial Content)及ERR_CONTENT_LENGTH_MISMATCH
nginx 缓冲区设置 proxy_buffers

代理后无法打开grafana页面

无论怎么刷新都是这个页面

通过分析发现有两个js无论怎么刷新都加载不到，服务器上这两个js是存在的/usr/share/grafana/public/build，并且都是大于2M的文件，合理怀疑是nginx配置问题。通过百度搜索发现可能是nginx的代理缓存不足的问题。




nginx代理配置改为

location  /grafana{
    proxy_buffering on;
    proxy_buffer_size 4k;
    proxy_buffers 8 4M;
    proxy_busy_buffers_size 4M;
    proxy_pass http://127.0.0.1:3000/grafana;
}

./nginx -s reload 重启nginx
再次访问页面，问题解决