State of preexisting connections when using file descriptor passing?

Question

I'm playing around with a webserver, using a unix socket and sendmsg / recvmsg to pass the socket file descriptor to a new server process without losing any requests. While testing it with ab I found that client connections would linger, and apachebench (ab) would show the error: "apr_poll: The timeout specified has expired (70007)".

I suspected that there was a change to the address of the file descriptor that would render open connections useless, however making sure the connections were closed at the end of every request didn't make a difference, a couple of the requests would fail.

Is there some extra oddity at the socket level or is ab just being weird? Is there anything else I should take into account?

Edit: Using PHP as a client to make requests also stalls during the cycle.

Answer 1

That's equivalent to trying to send a telephone over a telephone line. It doesn't make any sense. A socket fd identifies the endpoint of a connection. If another host wants a connection it will have to mke its own. You can't give it one of yours.