From: Jonathan Williams (jonathw@shubertorg.com)
Date: Thu Oct 17 2002 - 12:37:09 EDT
Well, the big thanks go to Martin Adolfsson with the following reply:
>Unfortunately I don't know of any useful command for this, but if the
>server is an application that is developed by your company/one that you
>have the sourcecode for, you might want to ask one of your programmers
>to make sure that SO_REUSEADDR is used in the call to bind() (See
>section 4.5 of
>ftp://rtfm.mit.edu/pub/usenet/news.answers/unix-faq/socket) since there
>is a possiblity that will help.
So I passed that little tidbit off to a programmer, and an hour later he emailed
me saying that he has a fix for the problem, and that the SO_REUSEADDR did it.
So thank you very much. I also received a bunch of emails that looked very much
like this:
>There are a few parameters that may help you in the "inet" subsystem of
sysconfigtab, they are
>
>tcp_keepalive_default
>tcp_keepcnt
>tcp_keepidle
>tcp_keepintvl
>
>Normally, in good network programming practice, a socket connection when
properly set up will >enable the keepalive timer and in the event of a broken
connection will clean itself up. >Unfortunately not all applications are written
like this so we have the tcp_keepalive_default. >Enabling this parameter (set it
to 1) will enable "keepalive" on all sockets created on the system, >this will
have the effect that you desire; to clean up broken connections. The default
setting of >tcp_keepalive_default is 0 (turned off). Once this is turned on then
sockets will be checked after >"keepidle" time and then will be checked for
"keepcnt" times; each time seperated by the >"keepintvl". If at the end of all
of this there is no socket communications the socket connection will >be cleaned
away. Once you set "keepalive" the defaults for the other parameters will not
clear a >socket connection for about 2 hours and ten minutes (if I remember
right) so you may want to >adjust the keepidle time to something more reasonable
(default 2 hours or 14400 half seconds).
>For more info check the man page for sys_attrs_inet.
Oh, and this is a good one too:
>I had a similar situation with an app on disconnect. There are a couple of
>parameters you can adjust in sysconfigtab. One is "tcp_keepidle". It's
>default is 1500 ticks and It was recommended by HPQ to adjust to 600. The
>other was "tcp_keepalive". These, I believe, are documented in the system
>configuration and tuning guide but I'm not at the office so I'm not sure.
>
>After these adjustments to the "inet:" stanza in sysconfigtab (use
>sysconfigdb to make the changes), our problem went away.
I would like to thank the following for there replies:
Blake Roberts, Rodney S, Steve VanDevender, Robert Mulley, Gary Luo, Pat
Barrowclough, Benjamin Smith, Dennis Sylvester, and Robert Collins.
Jonathan Williams
Unix Systems Administrator
The Shubert Organization, Inc.
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