request.flushHeaders()

request.flushHeaders()

Flush the request headers.

For efficiency reasons, Node.js normally buffers the request headers until you call request.end() or write the first chunk of request data. It then tries hard to pack the request headers and data into a single TCP packet.

That's usually what you want (it saves a TCP round-trip) but not when the first data isn't sent until possibly much later. request.flushHeaders() lets you bypass the optimization and kickstart the request.