[Linux-ha-dev] Shared disk file Exclusiveness control programforHB2

[Junko IKEDA]

Hi,

sorry, my previous answer was off the mark...
When 2 nodes reach there at the same time,
node A notices that the other node want to lock too, so give up lock itself.
node B is ready to lock.

Thanks,
Junko


> -----Original Message-----
> From: linux-ha-dev-bounces at lists.linux-ha.org
> [mailto:linux-ha-dev-bounces at lists.linux-ha.org] On Behalf Of Junko IKEDA
> Sent: Thursday, August 09, 2007 4:30 PM
> To: 'High-Availability Linux Development List'
> Subject: RE: [Linux-ha-dev] Shared disk file Exclusiveness control
> programforHB2
>
> Hi,
>
> You know that could be true...
> but if it's called from RA, 2 nodes wouldn't reach that part at the same
> time, right?
> One node will be able to reach there according to the score rule.
>
> Thanks,
> Junko
>
> > -----Original Message-----
> > From: linux-ha-dev-bounces at lists.linux-ha.org
> > [mailto:linux-ha-dev-bounces at lists.linux-ha.org] On Behalf Of Xinwei Hu
> > Sent: Thursday, August 09, 2007 3:00 PM
> > To: High-Availability Linux Development List
> > Subject: Re: [Linux-ha-dev] Shared disk file Exclusiveness control
program
> > forHB2
> >
> > Hi,
> >
> >   There's races in the sfex_lock.c.
> >
> >   When 2 nodes reach sfex_lock.c:265 in the same time.
> >
> >   node A: reserve lock -> wait for collision_timeout -> hold lock
> >   node B: sleep           -> sleep                             ->
reserve
> > lock
> >
> > $B:_(B $B at 14|;0(B 08 $BH,7n(B 2007 12:00$B!$(BNAKAHIRA Kazutomo $B<LF;!'(B
> > > Hello, all.
> > >
> > > We wrote a Shared Disk File EXclusiveness Control Program, called
> > > "SF-EX" for short, could prevent a destruction of data on
> > > shared disk file system due to Split-Brain.
> > >
> > > This program consists of CUI commands written in the C and RA,
> > > the former is used for managing and monitoring shared disk status
> > > and the latter is the same as other common RAs.
> > >
> > > We tested this program on IBM and HP platform, and we confirmed
> > > all functions worked well.
> > >
> > > Our test environment is listed below:
> > >  Software:
> > >   OS :RHEL4 ES Update5(kernel2.6.9-55.ELsmp)
> > >   HB2:heartbeat-2.1.2-2
> > >
> > >  Hardware:
> > >   IBM platform:
> > >    Server     : System x3650
> > >    Shared disk: DS 4700 (FC)
> > >
> > >   HP platform:
> > >    Server     : DL380G5
> > >    Shared disk: MSA500G2 (SCSI)
> > >
> > > How to install and configuration are described in README.
> > > If you are interested in this program, please try it and
> > > let me know your comments.
> > >
> > > Your suggestions on how to improve are really appreciated.
> > >
> > > Best regards.
> > _______________________________________________________
> > Linux-HA-Dev: Linux-HA-Dev at lists.linux-ha.org
> > http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev
> > Home Page: http://linux-ha.org/
>
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