From: Ben Greear <greearb@candelatech.com>
To: landley@webofficenow.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: Hour long timeout to ssh/telnet/ftp to down host?
Date: Tue, 12 Jun 2001 19:18:03 -0700 [thread overview]
Message-ID: <3B26CD5B.47002360@candelatech.com> (raw)
In-Reply-To: <01061217025700.02061@localhost.localdomain>
Rob Landley wrote:
>
> I have scripts that ssh into large numbers of boxes, which are sometimes
> down. The timeout for figuring out the box is down is over an hour. This is
> just insane.
>
> Telnet and ftp behave similarly, or at least tthey lasted the 5 minutes I was
> willing to wait, anyway. Basically anything that calls connect(). If the
> box doesn't respond in 15 seconds, I want to give up.
>
> Is this a problem with the kernel or with glibc? If it's the kernel, I'd
> expect a /proc entry where I can set this, but I can't seem to find one. Is
> there one? What would be involved in writing one?
>
You can tune things by setting the tcp-timeout probably..I don't
know exactly where to set this..
You probably don't want all tcp to time out at 15 seconds anyway, so
I'd suggest either using non-blocking connect (if you have the code
that does the connect), or just set a timer (or use sigalarm) when you
start the attempt, and fail the attempt if the timer or alarm signal
goes off.
> If it's glibc I'm probably better off writing a wrapper to ping the
> destination before trying to connect, or killing the connection after a
> timeout with no traffic. But both of those are really ugly solutions.
Ugly is relative, and don't use ping because there is still a race condition
(ping worked, but by the time you try tcp, the box is down.)
>
> Anybody have any light to shed on the situation?
>
> Rob
> -
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--
Ben Greear <greearb@candelatech.com> <Ben_Greear@excite.com>
President of Candela Technologies Inc http://www.candelatech.com
ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear
next prev parent reply other threads:[~2001-06-13 2:18 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-06-12 21:02 Hour long timeout to ssh/telnet/ftp to down host? Rob Landley
2001-06-13 2:18 ` Ben Greear [this message]
2001-06-12 21:47 ` Rob Landley
2001-06-13 9:40 ` Luigi Genoni
2001-06-13 10:07 ` Rob Landley
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