RE: Zombie / Orphan open files

["Frank Filz" <ffilzlnx@mindspring.com>]

> On Mon, Jan 30, 2023 at 5:44 PM Andrew J. Romero <romero@fnal.gov> wrote:
> >
> > Hi
> >
> > This is a quick general NFS server question.
> >
> > Does the NFSv4x  specification require or recommend that:   the NFS server,
> after some reasonable time,
> > should / must close orphan / zombie open files ?
> 
> Why should the server be responsible for a badly behaving client? It seems like
> you are advocating for the world where a problem is hidden rather than solved.
> But because bugs do occur and some customers want a quick solution, some
> storage providers do have ways of dealing with releasing resources (like open
> state) that the client will never ask for again.
> 
> Why should we excuse bad user behaviour? For things like long running jobs
> users have to be educated that their credentials must stay valid for the duration
> of their usage.
> 
> Why should we excuse poor application behaviour that doesn't close files? But in
> a way we do, the OS will make sure that the file is closed when the application
> exists without explicitly closing the file. So I'm curious how do you get in a state
> with zombie?

Don't automatically assume this is bad application behavior, though it may be behavior we don't all like, sometimes it may be for a reason. Applications may be keeping a file open to protect the file (works best when share deny modes are available, i.e. most likely a Windows client). Also, won't an executable be kept open for the lifetime of the process, especially if the executable is large enough that it will be paged in/out from the file? This assures the same executable is available for the lifetime of the process even if deleted and replaced with a new version.

Now whether this kind of activity is desirable via NFS may be another question...

Frank