I've got a self-written FastCGI backend. It works with Lighttpd, but not with Nginx. Nginx connects to the backend, sends the request, receives the response, but then appears to wait on something else.

The backend writes one or more FCGI_STDOUT packets and a FCGI_END_REQUEST packet. Any hints on what's wrong?

writev(10, [{"\1\1\0\1\0\10\0\0\0\1\0\0\0\0\0\0\1\4\0\1\3\212\6\0\f\0QUERY_"..., 952}], 1) = 952
epoll_wait(8, {{EPOLLIN|EPOLLOUT, {u32=3285521105, u64=139778701202129}}}, 512, 59998) = 1
recvfrom(10, "\1\6\0\1\2[\0\0Content-Type: text/html;"..., 4096, 0, NULL, NULL) = 635
readv(10, 0x7fff5452b860, 1) = -1 EAGAIN (Resource temporarily unavailable)
epoll_wait(8, {}, 512, 59962) = 0