auto-restart/resume slowed down FTP uploads?

SilveRo

So, let me explain this a little better.

My ISP NATs me, so I have to establish sessions in passive mode. I have a domain + hosting @ Aruba, and lately I have noticed that uploads have been limited to about 50 KB/sec. Now, this is not a major problem: even though I have much more upload bandwidth than that, I am patient, and I don't mind waiting a while for stuff like my photo album and my collection of fun videos to be updated.

But here is the REAL PROBLEM.

Very often (I don't know if it's happening randomly), all of a sudden the server stops accepting the upload; the speed, then, starts slowing down, tending to 0, without ever reaching it. Now, no error message comes up: it just seems as though the speed keeps decreasing, but what is actually happening is that no more data is being uploaded (it happens with both small and big files). I have witnessed this with lftp, yafc, ncftp, gftp... This is very anoying, because I have to constantly babysit every upload....

So, here is my question:
is it possible to have a client notice when the speed drops below, let's say, 30 KB, and automatically restart the connection, resuming the interrupted file and continuing with the others in the queue? What client does this? Would it be good to have a new connection for each file uploaded?

Probably it's the hosting provider's fault... I think so because Aruba offers all it's customers unlimited storage/traffic (and it's very cheap too)....

THX!!!

_________________
Think Gray
(things aren't all black or all white)

nemo_ · Posted: Thu Jan 27, 2005 10:48 am Post subject:

well, this is probably not exactly what you're looking for but most clients like ncftp have settings like xfer-timeout, autoretry etc, which you could adapt and then leave running at night.

you could also use the client's return code to run it again and again in a loop untill it finishes successfully like this :

SilveRo · Posted: Thu Jan 27, 2005 2:03 pm Post subject:

nemo_ · Posted: Thu Jan 27, 2005 2:37 pm Post subject:

also something else - you say that the transfer stops completely and that you see the speed decreasing slowly without ever reaching zero. I don't understand how that's possible

I mean, ok the client probably shows you an average speed since the upload started so it could take a while to go down, but if it's smart enough it should still realize at some point that no more data is transferred and trigger some xfer-timeout condition..

I guess the reason why you don't find the feature you're looking for is that it would be abused too much by kiddies hammering servers because they're not satisfied with their uplink hehe

would be best to investigate the cause of this drop, does it only happen with that particular FTP ? if so I'd probably get in touch with the admins there.
it could also be a connection problem (TCP will back down and your transfer speed will be suddently much lower if it experiences packet loss for example - but should still work a little at least). did you check if you have any errors/collisions/drops in ifconfig output for example ?

SilveRo · Posted: Thu Jan 27, 2005 4:29 pm Post subject:

Yeah, I thought it was absurd too when I first saw it, but that's how it is... The hosting provider must have found a way to make uploads tougher...

That's a good idea you gave me: I'll try to monitor the connection next time I upload something using FTP. I never thought of looking at ifconfig. I thought of contacting the hosting provider, but I don't know if they would listen to me... Customer support in Italy sucks...

Now that I think of it, it may also be my ISP's fault. Man, I hate NATting....

_________________
Think Gray
(things aren't all black or all white)