Re: Weirdness with AF_INET listen() backlog [2.4.18]

[Michael Kerrisk]

Hello Alan (et al.),

Thanks for the quick replies.

>> I had expected that if a server creates a listening socket, but does not
>> accept() the incoming connections, then after the (possibly
fudge-factored)
>> Is this all expected behaviour?  If so, is there a way of getting Linux
to
>> behave more like other implementations here?  (As a wild shot I tried
setting
>> /proc/sys/net/ipv4/tcp_syncookies to 0, but this made no apparent
>> difference.)
>
>The world of tcp synflooding changed how stacks handle this sort of
>stuff forever. Welcome to the new world order 8)

Yes, I was gathering that it was synflooding that led to these changes.

>You will get connections completing, they will time out.

What causes the delay of a few seconds following each of the connect()s
in excess of backlog?

> If you expect
>the server to say something you'll see the timeout there instead of
>seeing it on the connect.

Sorry, I don't quite understand this last sentence!  Can you elaborate?

>Since a timeout on the data can happen in the real world Im sure your
>code already correctly handles this case ;)

You mean on a send() or write(), right?

Cheers

Michael