Is FileZilla Client using Segmented Uploads?

[Rooster]

Dear FileZilla team,

I apologize in advance if this was already discussed in the forum but I couldn't found it.


My problem is actually not with FileZilla but with a 3rd party software.


With single file upload (one thread), I got only 1/3 of the speed I get with single FilleZilla upload. The issue concerns LTE mobile network. In order to get the same speed on my software, I need to use 3+ segments for the uploaded file (simultaneous file uploads are not possible). The issue is tested in multiple conditions/PCs and stays the same.

This software support claims that the problem is not in their software and the reason for higher throughput in FileZilla is because FileZilla uses segmented downloads/uploads.


I will be much obliged if you can share some information how FileZilla works and if there is a reason the throughput is lower with 3rd party software.

Thank you in advance for your support.

Best Regards,
Vladimir

[botg]

FileZilla doesn't use segmented transfers.

There are two main tricks for fast transfers:

The receiver must set a large enough advertised receive window to match the connection's maximum bandwidth-delay product. The sender's TCP send buffer is less important but still must be adequately sized to not go empty between calls to the socket's send function.

Asynchronous I/O must be used both for network and file reads/write.

[Rooster]

Dear botg,

Thank you for your quick response.

I'm not expert, but looking at your comment makes me think that something in their software might be wrong.

Best Regards,
Vladimir

[topbanana]

The third trick is to use say WinSCP to run a remote command on a big file you want to transfer down at full speed, to rar/split it in to chunks, perhaps of 20mb each, and then use FileZilla to transfer all the chunks down, making use of the "Maximum Simultaneous Transfers" option set to say 4 or 6 or even 10! This will then download the file, maxing out your connection, even on poorer internet connections, and/or many hops from the server. Then just unrar the file and delete the chunks. This will do exactly what you want, with a little bit of faffing around before and after, but you'll likely get your download jobs done many times faster than the single transfer of the big file.

http://winscp.net/eng/index.php WinSCP - Very good at allowing you to use custom remote commands.
Add a Custom Command:

Code: Select all

rar a -r -m0 -v20m "!.rar" "!"

'Remote Command', 'Apply to Directories', Add the Custom Commands toolbar.
This command will use Rar to spit the file/directory into 20mb numbered rar files using no compression, therefore very quickly. If you multi-select files, they'll each have their own multi-part rar file, nice.

We will still use Filezilla for transfering the files, using Simultaneous Transfers as it's by far the nicest/best working FTP client out there (even despite this missing, much needed functionality).

It's sad we have to faff around to get things done quicker...