Messages in this thread | | | Date | Tue, 12 Jun 2001 19:18:03 -0700 | From | Ben Greear <> | Subject | Re: Hour long timeout to ssh/telnet/ftp to down host? |
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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 > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
-- 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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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