Sockjs/socketio disconnect delay behind apache proxy

I need to handle users disconnecting from my sockjs application running in xhr-polling mode. When I connect to localhost, everything works as expected. When I put apache between nodejs and browser, I get ~20 sec delay between closed browser and disconnect event inside nodejs. My apache proxy config is following:

<Location />
  ProxyPass http://127.0.0.1:8080/
  ProxyPassReverse http://127.0.0.1:8080/
</Location>

The rest of the file is default, you can see it here. I tried playing with ttl=2 and timeout=2 options, but either nothing changes, or I get reconnected each 2 seconds without closing browser. How can I reduce additional disconnect timeout, introduced, but apache, somewhere in its defaults?

via Stepan Yakovenko