Backend usage / max_input_vars for bigger files

Out of curiosity:

Allowing for larger text uploads required setting max_input_vars to a rather high value – how come a 12MB file requires thousands of open POST connections in the panel?

I’m not sure I understand what’s happening there.
Uploading a file, no matter how big, should require only 1 post request. Or is this about “uploading” a 12MB text through a textarea in panel or something?

no, it’s the regular file upload. And it returns a debugging error in the vein of “max_input_vars of 4000 exceeded“.

Is it a .txt file?

Kind of – it’s a CSV

[Edit:] should be noted that I also got this error on a local setup with the default 1000 setting but had to choose a much higher value on the server.

Have you any plugins installed?
What Kirby version are you using?

I’m unable to reproduce the issue.

these two; though the page does not use any blocks:

jg/kirby-fields-block
fabianmichael/kirby-meta

Let me try to reproduce the error on a vanilla installation with the same file, though