On the client side, I get a "Socket closed." error. My HTTP client is
not configured to use keepalive, which makes the error message seem
The only 'weird' thing I am doing is sending a '100 Continue' response
from the back-end server.
Does nginx have different behavior when I send back a 100?
Does the client do POST and pass "Expect: continue" ?
nginx does not support "Expect: continue/100 Continue" dialog because
current browsers still do not support it (at least I never see).
So the client askes "Expect: continue", nginx passes the request
to backend, the backend responses "100 Continue". nginx sends it
to the client and goes to keep-alive state.