[Swift-devel] Re: swift-falkon problem

[Mihael Hategan]

On Thu, 2008-03-20 at 18:26 -0500, Ioan Raicu wrote:
> But the status file is written last, all from the same node, so in
> theory (would have to be tested, or at least verified by someone who
> knows NFS better than I do), if the status file appears, then the
> other files would also be there.  A year ago, there was no status
> file... this was added later.

Your assumption is incorrect. There was an exit code file written when
the application failed, but nothing written when the application
succeeded, causing ambiguity when the filesystem settings were wrong.

>   What was the main motivator for adding the status file?  Was is that
> you couldn't rely on the provider's exit codes?  Or something else?
> 
> Ioan
> 
> Ben Clifford wrote: 
> > On Thu, 20 Mar 2008, Ioan Raicu wrote:
> > 
> >   
> > > Why could Swift not have a retry mechanism, given that it received a
> > > successful exit code, be more persistent in looking for the success or failure
> > > file, and if it doesn't exist, to try it again after some small amount of
> > > sleep...  this would certainly hide (and potentially solve) the race
> > > condition, with a persisitent enough retry mechanism, wouldn't it?
> > >     
> > 
> > The goal is not just to find a status file; there is other stuff beign 
> > written to the shared filesystem and its not clear that the status files 
> > appearing would guarantee that the other files had appeared too.
> > 
> >   
> 
> -- 
> ===================================================
> Ioan Raicu
> Ph.D. Candidate
> ===================================================
> Distributed Systems Laboratory
> Computer Science Department
> University of Chicago
> 1100 E. 58th Street, Ryerson Hall
> Chicago, IL 60637
> ===================================================
> Email: iraicu at cs.uchicago.edu
> Web:   http://www.cs.uchicago.edu/~iraicu
> http://dev.globus.org/wiki/Incubator/Falkon
> http://dsl-wiki.cs.uchicago.edu/index.php/Main_Page
> ===================================================
> ===================================================
>