fix: doc interval setting for internet speed plugin

[powersj]

Fixes: #11148

[srebhan]

@powersj isn't that comment only true in combination with enable_file_download = true (which is false by default)? It might be a bit misleading to users...

[powersj]

The enable_file_download does not control whether a file gets downloaded or not. It controls a setting in the speed test library as to the workload/weight of the download itself. When enabled, it is a hard-coded setting; without it, the library adjusts based on the latency to the server. Check it out here.

The workload setting is the number of go threads to download something.

The weight is used to determine the size of MB to download:

var dlSizes = [...]int{350, 500, 750, 1000, 1500, 2000, 2500, 3000, 3500, 4000}
<snip>
reqMB := dlSizes[weight] * dlSizes[weight] * 2 / 1000 / 1000

edit: here is the actual download request which shows how to constructs a URL to download a specific sized jpg file.

[srebhan]

Oh so I always misinterpreted this one. Thanks for clarification!

[srebhan]

Looks good to me.

[powersj]

Oh so I always misinterpreted this one. Thanks for clarification!

you are not alone :) I did the same and wasn't until I looked deeper into the library did it I realize the config value we have is really poorly named :(