> Windows XP SP2

Oh... 

> 
> Now why would this leave open file descriptors? Is there 
> something I can do in the code to make sure they are closed properly?

No, I thought you were using a *nix'ish OS.

In case of Windows XP you have to take into account, that SP2 limits the
number of half open TCP connections to 10. So in case the box is under load
and takes longer than normal to close a socket, there is the possibility
that these "half open connections" will block any further connection
attempts. This is _not_ a database issue but a real limitation that was
built into SP2.

I'm sure if you try an XP box with SP1 you won't see this phenomenon. See an
exerpt of an article that describes the behaviour:


[...]
Windws XP SP2 introduces a few new twists to TCP/IP in order to babysit
users and "reduce the threat" of worms spreading fast without control. In
one such attempt, the devs seem to have limited the number of possible TCP
connection attempts per second to 10 (from unlimited in SP1). This
argumentative feature can possibly affect server and P2P programs that need
to open many outbound connections at the same time.

Rant: The forward thinking of Microsoft developers here is that you can only
infect 10 new systems per second via TCP/IP ?!?... Keep in mind that would
still make 10^60 in a single minute, (that's 10 with 60 trailing zeros...)
if everyone already infected also infects 10 new computers per second. In
other words, even though it is not going to stop worm spreading, it's going
to delay it a few seconds, limit possible network congestion a bit, and
limit the use of your PC to 10 connection attempts per second in the process
! I have no problem with the new default setting limiting outbound
connection attempts. Still, users should have the option to easily disable
or change this setting. I might be going out on a limb here, but ever since
the introduction of Windows XP I can't help thinking that I dislike all the
bult-in Windows "wisardry" in a sense that the system also limits user
access. That irritating trend to ease the mental load on end users is
somewhat insulting, considering that Windows is to make the more
"intelligent" choice instead of the end user, as well as limit their access
to tuning such settings...
End of rant.

[...]

You only need to worry about the number of connection attempts per second if
you have noticed a slowdown in network programs requiring a number of
connections opened at once. You can check if you're hitting this limit from
the Event Viewer, under System - look for TCP/IP Warnings saying: "TCP/IP
has reached the security limit imposed on the number of concurrent TCP
connect attempts". Keep in mind this is a cap only on incomplete outbound
connect attempts per second, not total connections. Still, running servers
and P2P programs can definitely be affected by this new limitation. Use the
fix as you see fit.

Source: http://www.speedguide.net/read_articles.php?id=1497


See here for another issue into that you may be running when connecting to
loopback addresses:

http://support.microsoft.com/default.aspx?scid=kb;EN-US;884020



Greetz,


SIEGENIA-AUBI KG
Informationswesen
 
i.A.
 
Markus D�hr
SAP-CC/BC, SAPDB-DBA

Tel.:    +49 6503 917-152
Fax:     +49 6503 917-7152
E-Mail: [EMAIL PROTECTED]
Internet: http://www.siegenia-aubi.com 
  

--
MaxDB Discussion Mailing List
For list archives: http://lists.mysql.com/maxdb
To unsubscribe:    http://lists.mysql.com/[EMAIL PROTECTED]

Reply via email to