Re: svn and svnserve hanging

On 2019-04-08 15:26:15 +0200, Stefan Sperling wrote:
> On Mon, Apr 08, 2019 at 02:38:15PM +0200, Vincent Lefevre wrote:
> > On 2019-04-08 13:57:32 +0200, Stefan Sperling wrote:
> > > There is insufficient information in your report for anyone to act upon.
> > > Most importantly, it is unclear which component in the chain is causing
> > > the problem. Is it SVN? Is it SSH? Is it TCP?
> > > Please try to find answers to these questions.
> >
> > I'm using SSH connection sharing and the master (started at 12:39,
> > i.e. the same master as with the hanging svn) is still working.
>
> Interesting. Does the problem also occur if you disable SSH
> connection sharing completely? Perhaps it is related?

This problem occurs not often enough to know (except by doing
background tests in a loop).

> > > You could try to get some information out of SSH? Perhaps the sshd
> > > server logs contain clues?
> >
> > I've asked the sysadmin, but since the SSH master still works,
> > I doubt that this would be related.
>
> How can you know that? My and your guesses are only as good as any
> other guesses. Until more information is surfaced which pins things
> down further we simply don't know anything at all about this problem.

If sshd would have detected an issue on its side, I would have
got some information on the client side, unless there is a bug
in the error reporting of openssh. On the client side, svn is
still hanging with no output, and no errors on the master ssh
debug output.

Still no answer for the sysadmin.

I can have lsof information on the server, in case this can provide
useful information:

* for sshd:
COMMAND PID TID USER FD TYPE DEVICE SIZE/OFF NODE NAME
sshd 48655 vlefevre cwd unknown /proc/48655/cwd (readlink: Permission denied)
sshd 48655 vlefevre rtd unknown /proc/48655/root (readlink: Permission denied)
sshd 48655 vlefevre txt unknown /proc/48655/exe (readlink: Permission denied)
sshd 48655 vlefevre NOFD /proc/48655/fd (opendir: Permission denied)

* for svnserve:
COMMAND PID TID USER FD TYPE DEVICE SIZE/OFF NODE NAME
svnserve 48724 vlefevre cwd DIR 0,32 4096 110673531 /home/users/vlefevre (...:/forge_home)
svnserve 48724 vlefevre rtd DIR 254,0 4096 2 /
svnserve 48724 vlefevre txt REG 254,0 86256 9413 /usr/bin/svnserve
svnserve 48724 vlefevre 0r FIFO 0,8 0t0 957950313 pipe
svnserve 48724 vlefevre 1w FIFO 0,8 0t0 957950314 pipe
svnserve 48724 vlefevre 2w FIFO 0,8 0t0 957950315 pipe
svnserve 48724 vlefevre 3r CHR 1,9 0t0 7109 /dev/urandom

(I've excluded the library files).

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)