On Mon, 03 Oct 2011 12:57:56 +0100, simendsjo <[email protected]> wrote:
On 03.10.2011 11:36, Regan Heath wrote:
For a "graceful" close you're supposed to ensure there is no data
pending. To do that you:
shutdown(SD_SEND); // send only, not recv
<enter a loop reading all data remaining on the socket>
close();
The loop should read until recv returns 0. If recv returns -1 and the
socket is blocking it should error/exit. If recv returns -1 and the
socket is non-blocking it should check for [WSA]EWOULDBLOCK (and
select/sleep + loop) or error/exit.
The reason to do this is to flush all the data from the socket buffers
on the remote and local ends, otherwise a close can cause remote
buffered data to cause a "connection broken" error on the remote end,
and/or (I am guessing a little here) may cause the socket to close while
negotiating a graceful close, and/or remain in a TIME_WAIT state due to
buffered data or data "in flight".
... are you setting any close options/timeouts i.e. LINGER?
Thanks.
:)
recv returns -1 for many requests. The errors are only WSAECONNABORTED
and WSAECONNRESET as described here:
http://msdn.microsoft.com/en-us/library/ms740668.aspx
To help me understand (I know nothing about fastcgi or nginx) can you
clarify...
1. Your D code is the client side, connecting to the web server and
sending GET/POST style requests?
2. You get these ABORTED and RESET errors on the client side?
3. As #3 even after doing as I described, shutdown(SEND), recv, then close?
If yes to all the above, then it sounds like the web server/fastcgi is
closing the socket without reading all the data you're sending, which
probably means you're sending something it's not expecting. I would start
by verifying exactly what data you're sending, and that it's all expected
by the remote end.
I'm doing socket.shutdown(SocketShutdown.SEND) now after sending all my
data and reading until I receive 0 or -1. (doesn't really matter as
sending the FastCGI EndRequest makes the server shut it down as it
doesn't handle multiplexing)
So, the socket closure is initiated by fastcgi/the web server. This
supports the theory that it's not reading some of your data, because it's
not expecting it, and this is likely the cause of the ABORT/RESET errors
you're seeing.
I have tried with linger too, but it doesn't help:
socket.setOption(SocketOptionLevel.SOCKET, SocketOption.LINGER,
std.socket.linger(1, 30));
The default LINGER options should be fine, as-is. But, double check the D
socket code just in case it is setting different LINGER options by default
(I haven't used it, or looked myself, sorry).
Could this be caused by some bad settings on the webserver?
It is possible, but I would double check your requests first. There may
be a setting, or settings for aborting connections which take too long, or
fail to send certain data, or connect from the wrong IP, or... If your
requests are otherwise working, then I suspect you're sending some 'extra'
data which is not being read.
PS: Seems my computer can handle about 16000 TIME_WAIT before it starts
"hanging".
You'll be running out of operating system handles or similar at that point
:p
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