Well, it's not a big problem - you should have a timeout on incoming connections, and node is pretty well-suited for having lots of "hanging" connections (I ran some test with 56k active connections).
If a connection is closed, either by a timeout, or EOF, you simply check if the promised content length matches the count of received bytes - if not you should probably discard the whole thing (unless you're specifically supporting broken clients).
If a connection is closed, either by a timeout, or EOF, you simply check if the promised content length matches the count of received bytes - if not you should probably discard the whole thing (unless you're specifically supporting broken clients).