[pve-devel] [PATCH pve-manager] pvestatd: stream host pressure counters

[Thomas Lamprecht]

On 24.10.20 15:46, Alexandre Derumier wrote:
>> Sounds reasonable. We just need to find a way to add new values
>> in a compatible way.
> 
> Last time in 2013, we had added a new rrd "pve2.3-vm/"
> https://lists.proxmox.com/pipermail/pve-devel/2013-January/005612.html

that'd drop all old statistics, and be a bit of a nuisance to upgrade inside
a cluster (old nodes get stuff they do not comprehend).

We may rather want to have a new, separate, file for this.
We could add general support for and error handling now, and to the final add
with 7.0 next year or so. Maybe there's even a way to add it now without other
nodes producing errors, but from top of my head I am not sure..

In Proxmox Backup Server we have each metric in a separate file, makes it a bit
easier to extend on.

# ls -l /var/lib/proxmox-backup/rrdb/host/
total 160
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 cpu
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 io_ticks
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 iowait
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 loadavg
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 memtotal
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 memused
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 netin
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 netout
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 read_bytes
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 read_ios
-rw-r--r-- 1 backup backup 6008 Jun  4 18:03 read_ticks
-rw-r--r-- 1 backup backup 6008 May 28 13:00 roottotal
-rw-r--r-- 1 backup backup 6008 May 28 13:00 rootused
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 swaptotal
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 swapused
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 total
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 used
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 write_bytes
-rw-r--r-- 1 backup backup 6008 Oct 23 07:45 write_ios
-rw-r--r-- 1 backup backup 6008 Jun  4 18:03 write_ticks


We could say we keep the base stuff as is in a single file and add
the new one with a "<vmid>.<metric-name>" scheme.