Hi,

I have nginx set up as proxy to node.js for long polling like this:

location /node1 {
access_log off;
log_not_found off;
proxy_pass http://127.0.0.1:3001/node;
proxy_buffering off;
proxy_read_timeout 60;
break;
}

Unfortunately about half of long poll requests returns with error and empty response. I verified that is nginx issue as polling node.js directly with curl is always working and polling through website is reproing the issue. My version of nginx is the one dreamhost offers v.0.8.53.

Do you know how can I mitigate the issue and what can be the problem? The other GET, non-polling requests that are going same route are working just fine so I suspect some timeout issue. The long poll is set up for about 30 seconds in node.

Thanks for any help!

I turned on logging and it seems that the failed requests do not even appear in the access_log as if the nginx never received it. So the case is that:

querying node.js directly like:
curl --connect-timeout 60 --max-time 60 --form "username=User" http://127.0.0.1:3001/node/poll/2/1373730895/0/0

works fine, but going through nginx:

curl --connect-timeout 60 --max-time 60 --form "username=User" http://www.mydomain.com/node1/poll/2/1373730895/0/0

is failing in half cases - the failed cases do not appear in the access_log and the curl returns:
curl: (52) Empty reply from server

It might be connected with higher traffic volume as well as I don't see that yet on other site that has lower traffic and should have similar settings.