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.
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.