It's slow towards the end of the download

Hi @zgchen333 @miguelmartin ,

I have made some downloading attempts and here are the results. Noting that before these tryings I have successfully downloaded more than 90% of takes of benchmark “proficiency” but get an error every time when downloading the remaining 10% takes.

First, I tried to print all the paths to be fetch and the results (posted below) show that all the failed fetched takes are from university “iiith”.

Second, I found that when I try to download without a VPN, I will get a WARNING on “Bucket Failures”. The same issue has also been posted on another question (posted below). Additionally, this WARNING is also about “iiith”.

Third, when I am trying to download without a VPN, I will not get the “Bucket Failures”. However, I still got the error.

WARN: failed to fetch 289 files [integrity=0, exceptions=289]
Please retry the download (… returning with error code 2)

It seems that a VPN may not help to solve this problem. Moreover, it seem that there is something wrong on the data from “iiith”.

Hopefully these tryings can help identify the real problem. If there is something I have missed or there are better solutions on this series of questions, please let me know.