Django+gunicorn+nginx upload large file 502 error

Problem Uploading 1-2mb files works fine. When I attempt to upload 16mb file, i get 502 error after several seconds More detalied: - I click "Upload" - Google Chrome uploads file (upload status is changing from 0% to 100% in left bottom corner) - Status changes to "Waiting for HOST", where HOST is my site hostname - After a half of minute server returns "502 Bad Gateway" My view: ``` def upload(request): if request.method == 'POST': f = File(data=request.FILES['file']) f.save() return redirect(reverse(display), f.id) else: return render('filehosting_upload.html', request) ``` render(template, request [,data]) is my own shorthand that deals with some ajax stuff; The `filehosting_upload.html`: ``` {% extends "base.html" %} {% block content %} <h2>File upload</h2> <form action="{% url nexus.filehosting.views.upload %}" method="post" enctype="multipart/form-data"> {% csrf_token %} <input type="file" name="file"> <button type="submit" class="btn">Upload</button> </form> {% endblock %} ``` Logs & specs There are nothing informative in logs i can find. Versions: - Django==1.4.2 - Nginx==1.2.1 - gunicorn==0.17.2 Command line parameters ``` command=/var/www/ernado/data/envs/PROJECT_NAME/bin/gunicorn -b localhost:8801 -w 4 PROJECT_NAME:application ``` Nginx configuration for related location: ``` location /files/upload { client_max_body_size 100m; proxy_pass http://HOST; proxy_connect_timeout 300s; proxy_read_timeout 300s; } ``` Nginx log entry (changed MY_IP and HOST) ``` 2013/03/23 19:31:06 [error] 12701#0: *88 upstream prematurely closed connection while reading response header from upstream, client: MY_IP, server: HOST, request: "POST /files/upload HTTP/1.1", upstream: "http://127.0.0.1:8801/files/upload", host: "HOST", referrer: "http://HOST/files/upload" ``` Django log ``` 2013-03-23 19:31:06 [12634] [CRITICAL] WORKER TIMEOUT (pid:12829) 2013-03-23 19:31:06 [12634] [CRITICAL] WORKER TIMEOUT (pid:12829) 2013-03-23 19:31:06 [13854] [INFO] Booting worker with pid: 13854 ``` Question(s) - how to fix that? - is it possible to fix that without nginx upload module? Update 1 Tried suggested config ``` gunicorn --workers=3 --worker-class=tornado --timeout=90 --graceful-timeout=10 --log-level=DEBUG --bind localhost:8801 --debug ``` Works fine for me now.