MicrostockGroup

I am running into major upload issues with most of the stock video sites.  Because video files are so large, they can take a VERY long time to upload depending on your connection speed.

Using CuteFTP or FileZilla, I run into an issue that if left unattended, they will think that a file has not been successfully uploaded and will attempt to re-upload the file.  On a number of sites (such as Shutterstock) this results in many duplicate copies uploaded of the same file.

Since I am a programmer, I decided to write my own FTP program to try and diagnose the issue.  And what I discovered is that on those sites where I have the problem, the FTP server closes the control connection while the file is uploading.  So when the upload is done, the client software gets a time-out error trying to talk to the FTP server through the closed connection.  Most FTP clients assume this means the file was not successfully uploaded and attempt to upload the file again.

The root of the problem is actually the fault of the Stock Sites.  FTP servers are NEVER supposed to close a control connection if there is an active data connection.  The stock sites are not enabling (or disabling) this feature in their FTP servers.

I have tried to discuss this with the sites I have these issues with: Shutterstock, Fotolia, Clip Canvas, Can Stock and Dreamstime with little success.   Either they don't understand what I am talking about, or they don't care.

So my only solution is to try and find a client program that does not attempt to re-upload files. 

Does anyone have any suggestions?  This is not so much an issue with photos as they are smaller and can be uploaded before the control connection is closed.  Only when you start uploading 200 megabyte files and larger does this issue rear its ugly head.

Have you tried the 'keep-alive' option in Filezilla->Edit->Settings->FTP?

The problem with FileZilla (and CuteFTP and a half-dozen other programs I tried) is that it does FTP transfers multi-threaded.  So keep-alives work in the primary thread on some servers (not all) but in the data thread the control connection is still closed and it still causes FZ to re-upload the file.

I have tried to bring this to the attention of the FZ author but because the underlying issue is a bug or misconfiguration of the server software, he refuses to do anything about it.  He's a brilliant programmer, but an incredible ass with very poor social skills.

Yup, passive mode.  I'll give that a try, but on many sites keep-alives don't work because the server closes any control connection that does not initiate a transfer within 3 to 5 minutes.  So, if I am uploading a file that takes 30 minutes to upload and FZ (or my own test program) is sending keep-alive commands the control connection is still closed because it doesn't initiate a new transfer.

For the moment I am just using my own program that I wrote and having it ignore the connection error.  That pretty much works, but I wrote it as a command line utility, so I have to stick a GUI on it to make it more useful.  In the meantime, I'm still hopeful of finding something else that works.

Did you try to disable multi-thread in CuteFTP? I had to do it because of Crestock.