My node.js app is getting an Unhandled 'error' event randomly on writing requests after I had put it behind nginx - node.js

Question

I am running node.js(0.8.20 and 0.9.10) on windows 2012 server. I have ran it absolutely without any problems for weeks. That was without Nginx(1.2.6) in front. With nginx in front configured like this:
#user nobody;
worker_processes 1;
#error_log logs/error.log;
#error_log logs/error.log notice;
#error_log logs/error.log info;
#pid logs/nginx.pid;
events {
worker_connections 1024;
}
http {
include 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"';
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
upstream dem2 {
server 127.0.0.1:8080;
}
server {
listen 80;
server_name dem2.cz dem2;
access_log /nginx-1.2.6/logs/dem2.log;
location / {
#proxy_pass http://127.0.0.1:8080/;
proxy_pass http://dem2/;
proxy_set_header X-Real-IP $remote_addr;
proxy_redirect off;
}
}
server {
listen 80;
server_name localhost;
location / {
root html;
index index.html index.htm;
}
}
}
On requests, I randomly get this error in Node.js app:
events.js:69
throw arguments[1]; // Unhandled 'error' event
^
Error: socket hang up
at createHangUpError (http.js:1383:15)
at ServerResponse.OutgoingMessage._writeRaw (http.js:499:26)
at ServerResponse.OutgoingMessage._send (http.js:466:15)
at ServerResponse.OutgoingMessage.end (http.js:911:18)
at SendStream.notModified (C:\dem2cz_node_app\node_modules\express\node_modules\send\lib\send.js:223:7)
at SendStream.send (C:\dem2cz_node_app\node_modules\express\node_modules\send\lib\send.js:353:17)
at SendStream.pipe (C:\dem2cz_node_app\node_modules\express\node_modules\send\lib\send.js:322:10)
at Object.oncomplete (fs.js:93:15)
Process finished with exit code 1
I suspect I have something wrong configured in Nginx, but I sure as hell don't know what it could be. Could anyone advise please?
I can post the node.js code too if you want, but it is nothing fancy, just 100 line express app for serving AngularJS static files with the option to serve HTML generated in PhantomJS when there is a bot.

Answer 1

There was a bugfix in 0.8.20 which significantly raised the number of "http hang-up" errors you get. They talk about it in the release notes. As #robertkelp said, it's nothing to worry about, but you should catch error events emitted by the http server to avoid crashing the server.