[distcc] Re: More debugging info for FIN_WAIT1 bug with RH 6

Hien D. Ngo hien at moses.xp.com
Fri Sep 6 02:23:03 GMT 2002

Attached is the tcpdump log of a FIN_WAIT1 transaction.  Let me know if you need a 
more detailed tcpdump (i.e. with different options other than just 'tcpdump host 


---- Original Message ----
From:		Martin Pool
Date:		Thu 9/5/02 18:53
To:		Hien D. Ngo
Cc:		distcc at lists.samba.org
Subject:	[distcc] Re: More debugging info for FIN_WAIT1 bug with RH 6

On  5 Sep 2002, "Hien D. Ngo" <hien at moses.xp.com> wrote:
> Turning off tcp_cork seems to make the problems under RH 6 go away; no more 
> FIN_WAIT1 connections, netstat is completely clean.  Turning tcp_cork off also 
> for me on the RH 7 machines, so I can happily build with distcc now on all my 
> machines :)  

OK, that's good.  Things should work fine without corks.  They may
just give a performance boost under some circumstances.

> BTW, the FIN_WAIT1 connections never die off, they just keep
> accumulating as far as I can tell.

That's interesting.  In a way that makes sense: if there is no timer
on the socket to clean it up, then we should expect them to remain
forever.  It's additional evidence for the hypothesis that the kernel
really is failing to set the timer, rather than (say) netstat just
failing to report it.

Even though distcc is now working, I would really appreciate it if you
would try to get a tcpdump of reproducing the problem.  It really
looks like it is a kernel bug and I would like to characterize it and
pass it on to the TCP maintainers.

distcc mailing list
distcc at lists.samba.org

-------------- next part --------------
22:16:21.690340 build03.foo.com.1146 > build04.foo.com.4200: S 1541177197:1541177197(0) win 32120 <mss 1460,sackOK,timestamp 1005928219[|tcp]> (DF)
22:16:21.690537 build04.foo.com.4200 > build03.foo.com.1146: S 1546103786:1546103786(0) ack 1541177198 win 32120 <mss 1460,sackOK,timestamp 1005835757[|tcp]> (DF)
22:16:21.690593 build03.foo.com.1146 > build04.foo.com.4200: . ack 1 win 32120 <nop,nop,timestamp 1005928219 1005835757> (DF)
22:16:21.691329 build03.foo.com.1146 > build04.foo.com.4200: P 1:1448(1447) ack 1 win 32120 <nop,nop,timestamp 1005928219 1005835757> (DF)
22:16:21.691822 build04.foo.com.4200 > build03.foo.com.1146: . ack 1448 win 31856 <nop,nop,timestamp 1005835757 1005928219> (DF)

ngoh at build03.foo.com $ netstat -ton | grep 4200
tcp        0     44      FIN_WAIT1   off (0.00/0/0)

ngoh at build04.foo.com $ netstat -ton | grep 4200
tcp        0      0     ESTABLISHED off (0.00/0/0)

More information about the distcc mailing list