[pve-devel] applied: [PATCH http-server] fix #6230: increase allowed post size

[Thomas Lamprecht]

Am 03.04.25 um 10:27 schrieb Dominik Csapak:
> In some situations, e.g. having a large resource mapping, the UI can
> generate a request that is bigger than the current limit of 64KiB.
> 
> Our files in pmxcfs can grow up to 1 MiB, so theoretically, a single
> mapping can grow to that size. In practice, a single entry will have
> much less. In #6230, a user has a mapping with about ~130KiB.
> 
> Increase the limit to 512KiB so we have a bit of headroom left.
> 
> We have to also increase the 'rbuf_max' size here, otherwise the request
> will fail (since the buffer is too small for the request). Since the
> post limit and the rbuf_max are tightly coupled, let it reflect that in
> the code. To do that sum the post size + max header size there.
> 
> A short benchmark shows that it only slightly impacts performance for
> the same amount of data (but that could be runtime variance too):
> 
> I used a 4 node virtualized cluster, benchmarked with oha[0] with these
> options:
> 
> oha --insecure -H $COOKIE -H $CSRFTOKEN -D bodyfile -m "PUT" -T
> "application/x-www-form-urlencoded" -n 3000 -c 50 --disable-keepalive
> --latency-correction https://<IP>:8006/api2/json/cluster/mapping/pci/test
> 
> So 3000 requests with 50 parallel. I also restarted pveproxy and daemon
> in between runs, and took the rss values around the 50% runtime of the
> benchmark.
> 
>                     average time  requests/s  pvedaemon rss   pveproxy rss
> old with 60k body   3.0067s       16.3487     140M-155M       141M-170M
> new with 60k body   3.0865s       15.7623     140M-155M       141M-171M
> new with 180k body  8.3834s       5.8934      140M-158M       141M-181M
> 
> Using a bigger body size had a large impact on the time, but that's IMHO
> expected. Also, RSS is not that much impacted, only when using many
> requests with larger request size, but this should also be expected.
> 
> 0: https://github.com/hatoo/oha
> 
> Signed-off-by: Dominik Csapak <d.csapak at proxmox.com>
> ---
> changes from rfc:
> * s/buffer/headroom
> * added benchmark data to the commit message
> * corrected rbuf_max calculation
> 
>  src/PVE/APIServer/AnyEvent.pm | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
>

applied, thanks!