[pve-devel] [RFC many 0/3] combine and simplify RRD handling

[Aaron Lauterer]

sent a v1 
https://lore.proxmox.com/pve-devel/20250905135517.4005478-1-a.lauterer@proxmox.com/T/#t

On  2025-09-04  16:09, Aaron Lauterer wrote:
> this series does two things:
> * switch the RRD API backend to use the old RRD files is available
> * always use RRD files with the new 9.0 schema
> 
> The motivation for the combination of old and new RRD files is that during the
> migration of old RRD files to the new ones, spikes get flattened. By combining
> the old and new RRD files, we can keep the old coarse data with all it spikes
> and only show the new much mode finer stepped data where available.
> 
> This will also enable us to just write any new data into an RRD file that is
> created with the new 9.0 schema. As a result, no migration step is needed
> anymore and we can simplify the logic around the whole "does the only the old
> file exist or is the new one also present" alot in quite a few places.
> 
> Some examples which we can simplify or revert:
> pve-manager: API2Tools::get_rrd_key can most likely be dropped
> qemu-server, pve-storage, pve-container,…: rrd API endpoints which check which files exist
> drop the whole migration step on upgrade
> 
> other TODOs:
> 
> RRD::create_rrd_graph -> see if we can combine both files into one graph. But we
> are relying on RRD itself for this. So that might be interesting. On the other
> hand, do we want to keep that API endpoint around? People are using it though.
> So we need to weigh that decision accoringly.
> 
> 
> This is currently marked as RFC. Tested by installing it on an existing 9.0.6
> cluster. Added a 8.4 node with latest updates. Renamed {rrd}.old to {rrd}.
> 
> cluster:
> 
> Aaron Lauterer (3):
>    rrd: fix rrd time frames
>    RRD: fetch data from old rrd file if present and needed
>    pmxcfs: status.c: always use 9.0 rrd files
> 
>   src/PVE/RRD.pm      | 113 ++++++++++++++-------
>   src/pmxcfs/status.c | 238 ++++++--------------------------------------
>   2 files changed, 108 insertions(+), 243 deletions(-)
> 
> 
> Summary over all repositories:
>    2 files changed, 108 insertions(+), 243 deletions(-)
>