[pbs-devel] [PATCH proxmox-backup] fix #5622: backup client: properly handle rate/burst parameters

[Christian Ebner]

On 7/23/24 12:04, Dominik Csapak wrote:
> the rate and burst parameters are integers, so the mapping from value
> with `.as_str()` will always return `None` effectively never
> applying any rate limit at all.
> 
> To fix it, just map from u64 to HumanByte.
> 
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---

Did some tests on this and while the rate limit gets applied, the burst 
value does not seem to be honored for my case. Am I misinterpreting the 
burst parameter or is there still an underlying issue?

Here is what was tested:
- Monitor network throughput to localhost by running `tcpsubnet-bpfcc 
127.0.0.1/32` as well as `iftop` (got only low additional traffic noise 
without invoking the proxmox-backup-client).
- Before each proxmox-backup-client invocation, the chunks and snapshots 
were deleted from the datastore to have similar conditions.
- Backup using proxmox-backup-client to local datastore via localhost by 
running `proxmox-backup-client backup usr.pxar:/usr --rate=100000`, rate 
limit is now honored as expected!
- `proxmox-backup-client backup usr.pxar:/usr --rate=100000 
--burst=1000000000000`, expected to reach much higher initial burst 
throughput because of the huge bucket size, but rate is limited to the 
same rate as above already from the beginning.
- Without rate limit, much higher rates can be reached, so that is not 
the limiting factor.