Messages in this thread | | | Date | Sun, 6 Jul 2003 23:20:42 -0700 | From | "Paul Albrecht" <> | Subject | Re: question about linux tcp request queue handling |
| |
Nivedita Singhvi writes:
> > When you set a the backlog to 1 in the listen call, what is > being capped is the accept queue. So I would expect your > server to allow only one of those requests in the accept > queue, and the kernel will drop the other two requests. >
What you get when you set backlog to one is operating system dependent. Tracing the flows with tcpdump, I get two clean handshakes so presumeably, for linux, one means two. The third connection request *isn't* dropped; according to netstat, it's placed in the syn_recd state. I thought berkeley-derived implementations followed the rule that if there is no room on the backlog queue for the new connection, tcp ignored the the received syn.
> > Actually, details, but we also apply some other conditions > before we actually drop the connection request - we try not to be > so harsh if the syn queue is still fairly empty.. >
Irrespective of whatever conditions linux applies, how can the connection enter the syn_recd state if the backlog limit would be exceeded? What's the client supposed to do with the syn/ack from the server? What's the server supposed to do with the ack it get's back from the client?
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |