[pve-devel] [PATCH manager 2/3] add broadcast for new rrd format

[Tobias Böhm]

> 
> >  	PVE::Cluster::broadcast_rrd("pve2.3-vm/$vmid", $data);
> > +	PVE::Cluster::broadcast_rrd("pve5.0-vm/$vmid", $data50);
> 
> I don't really want to duplicate cluster traffic, i.e. all information
> is contained in "pve5.0-vm/$vmid", so we can extract that on the
> receiver side.
> But do we really want that (what for)?
> 

The idea was to introduce a new extended version and later ignore the
previous one. Of course, duplicate traffic would be the downside of this
approach for the time until broadcasting the old version is removed.

I might have misinterpreted your suggestion to Jason Watson [1] about
that approach:

> Inside pmxcfs, we simply write pve4.0-vm data into another rrd file
> (and ignore pve2.3-vm messages"ignoring 2.3 messages" 

So, what would be the better way to handle this?

The alternative approach I see would be not to introduce a new rrd
version as replacement for the previous one, but to introduce a new
additional rrd that gets only handles the additional new data. And
clients would look up all available data. So the parts reading the data
need to be able to read from multiple sources.

What are your thoughts about that?

[1] https://pve.proxmox.com/pipermail/pve-devel/2015-November/018096.html