如何修复生产中的502坏网关错误（Nginx）？

Question

当我试图上传一个大小约为600MB的大csv文件在我的项目中托管在数字海洋，它试图上传，但显示502坏网关错误（Nginx）。

该应用程序是一个数据转换应用程序。

这在本地工作时很好。

sudo tail -30 /var/log/nginx/error.log

节目

[error] 132235#132235: *239 upstream prematurely closed connection while reading response header from upstream, client: client's ip , server: ip, request: "POST /submit/ HTTP/1.1", upstream: "http://unix:/run/gunicorn.sock:/submit/", host: "ip", referrer: "http://ip/"

sudo nano /etc/nginx/sites-available/myproject

节目

server {
    listen 80;
    server_name ip;
    client_max_body_size 999M;

    location = /favicon.ico { access_log off; log_not_found off; }
    location /static/ {
       alias  /root/static/;
    }
    location / {
        include proxy_params;
        proxy_pass http://unix:/run/gunicorn.sock;
    }
}

nginx.conf

user root;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
        worker_connections 768;
        # multi_accept on;
}

http {

        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        # server_tokens off;

        # server_names_hash_bucket_size 64;
        # server_name_in_redirect off;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

在转换过程发生时，我还运行了javascript加载器。我怎么才能修好这个？

Answer 1

如果您使用的是Django3.1或更高版本，您可以通过这种方式使文件处理异步，并在文件转换发生时向用户返回响应。你的视野应该是这样的...

    import asyncio
    from django.http import JsonResponse
    from asgiref.sync import sync_to_async
    
    
    @sync_to_async
    def crunching_stuff(my_file):
        # do your conversion here
            
    async def upload(request):
        json_payload = {
            "message": "Your file is being converted"
        }
        my_file = request.POST.get('file')
        
        asyncio.create_task(crunching_stuff(my_file))
        return JsonResponse(json_payload)

在前端，如果使用dropzone.js，用户可以看到文件上传的进度，并且可以更快地得到响应。这是更好的用户体验。https://www.dropzonejs.com/