Hello Maxim,

thanks a lot for your explanation. I've (kind off) solved the problem for now.

I was testing with another proxy in between nginx and the Jetty server to see whether that would behave differently. I just used Twitter's finagle, which is based on Netty and got a few error messages like this:

18.09.2013 11:59:58 com.twitter.finagle.builder.SourceTrackingMonitor handle
FATAL: A server service unspecified threw an exception
com.twitter.finagle.ChannelClosedException: ChannelException at remote address: localhost/127.0.0.1:8082
at com.twitter.finagle.NoStacktrace(Unknown Source)

So I tried to dig deeper on the Jetty side of things.

In the end, I just upgraded the web application running inside of Jetty and this solved the problem. Maybe I should make this a reflex: first update everything to the latest version before even trying to understand the problem, but that's not so easy to do in general...

Thanks again!