[ic] Perl 5.8.0 + Interchange Clustering locking issues

Dan Browning interchange-users@icdevgroup.org
Mon Sep 9 22:18:01 2002


At 10:01 PM 9/9/2002 -0400, you wrote:
>On Mon, Sep 09, 2002 at 06:45:02PM -0700, Barry Treahy, Jr. wrote:
> > Dan Browning wrote:
> >
> > >At 09:36 PM 9/8/2002 -0700, you wrote:
> > >
> > >>At 10:28 PM 7/27/2002 +0200, you wrote:
> > >>
> > >>>>Dan Browning wrote:
> > >>>>
> > >>>>>For fun, I was testing Perl 5.8.0 (default build options) on our
> > >>>>>Interchange cluster and found some file locking problems.  We'll
> > >>>>>be sticking with 5.6.1 for now, but I wanted to warn those who run
> > >>>>>clusters just in case they try it:
> > >>>>>x.x.x.x - - [27/July/2002:12:10:03 -0700] www11
> > >>>>>/cgi-bin/template/index.html Runtime error: Could not lock file:
> > >>>>>Interrupted system call
> > >>>>>It occurs even under very light loads, with MySQL sessions, and
> > >>>>>everything else shared over NFS3 (fcntl locks).  Perhaps it will
> > >>>>>be fixed in Perl 5.8.1...
>
>
>How do you know that is perl related and not NFS or NFS3?

It could be a NFS configuration problem, but here is what I know:

  * 5.6.1 works fine for our cluster (NFS)

  * Barry doesn't use NFS, neither does he have a cluster, but is
    experiencing the same problem with 5.8.0.

>At least
>in debian world, NFS defaults just changed to sync from async.  Perl
>changed from unthreaded to threaded.

That was gutsy, but I guess the threading is supposed to be a lot better in 
5.8.x.  Of course, I've known Debian to be everything except gutsy, so...

>If you are running mysql sessions,
>what do you have to lock?  An order counter and some log files?

tmp/*

>Why
>do you need to lock index.html?  Couldn't it be ro FWIW?

It isn't locked, it only reports the error.  The only NFS directories are:

etc/
orders/
products/
tmp/

Everything else is sync'ed via CVS.  Of all those, tmp is the one that 
causes the most lock contention.

>I'm confused AND about to upgrade to 5.8 on our production machines
>ATRSN.  :-)

WDATSF? [1]  :-)

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