[Gluster-devel] Update md-cache after triggering FOP via syncop framework?

[David Spisla]

Hello Niels,

yes, this seems to be a good idea. In a few hours I have to travel to an IT
conference. So I will start to try your suggestion next week.

Regards
David

2018-06-05 11:44 GMT+02:00 Niels de Vos <ndevos at redhat.com>:

> On Tue, Jun 05, 2018 at 11:04:00AM +0200, David Spisla wrote:
> > Hello Niels,
> >
> > thank you. Now I understand this better.
> > I am triggering the FOPs via syncop directly from the WORM Xlator which
> is
> > unfortunately below the upcall xlator.
> > I don't have a separate xlator, so I am searching for a solution which is
> > working inside of the WORM Xlator.
> > E.g. the autocommit function of the WORM Xlator is using the syncop
> > framework to change the atime
> > of a file. I don't know if there is a difference between FOPs triggered
> by
> > syncop or by clients from outside.
> > My guess is that there is no difference, but I am not sure.
>
> You can experiment with moving the WORM xlator in the .vol files of the
> bricks before upcall, just restart the brick processes after editing the
> config files.
>
> I can not immediately think of a reason why this would cause problems.
> You could send a patch that explains your need and changes the location
> of WORM (or upcall?) in the graph (see server_graph_table in
> xlators/mgmt/glusterd/src/glusterd-volgen.c).
>
> Niels
>
>
> >
> > Regards
> > David
> >
> > 2018-06-05 9:51 GMT+02:00 Niels de Vos <ndevos at redhat.com>:
> >
> > > On Mon, Jun 04, 2018 at 03:23:05PM +0200, David Spisla wrote:
> > > > Dear Gluster-Devels,
> > > >
> > > > I'm currently using the syncop framework to trigger certain file
> > > operations
> > > > within the Server Translators stack. At the same time, file
> attributes
> > > such
> > > > as file rights and timestamps are changed (atime, mtime). I noticed
> that
> > > > the md-cache does not get the changed attributes or only when the
> upcall
> > > > xlator is activated eg by a READDIR (executing " $ stat * ").
> > > > However, I would find it cleaner if right after triggering a file
> > > operation
> > > > by the syncop framework that would update md-cache. Is there a way to
> > > > programmatically do this within the Server Translators stack?
> > >
> > > Hi David,
> > >
> > > If you place your xlator above upcall, upcall should inform the clients
> > > about the changed attributes. In case it is below upcall, the internal
> > > FOPs can not be tracked by upcall.
> > >
> > > Upcall tracks all clients that have shown interest in a particular
> > > inode. If that inode is modified, the callback on the brick stack will
> > > trigger a cache-invalidation on the client. I do not think there should
> > > be a difference between FOPs from other clients, or locally created
> ones
> > > through the syncop framework.
> > >
> > > In case this does not help or work, provide a little more details (.vol
> > > file?).
> > >
> > > HTH,
> > > Niels
> > >
>
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