Strange upload behaviour

[Henkie]

Hi, I'm experiencing a strange issue when uploading files. It seems to occur more and more often lately, I don't know if this is related to FileZilla updates (I'm always using the latest version) or server changes or whatever.

Here's the thing: after connecting, when I drag & drop a bunch of files to the remote panel to be uploaded, the uploads start and the progress bars appear. However it seems to upload at an incredibly (impossible) speed, e.g. uploading a 30 MB file within 1-2 sec or so. The upload speed is specified like 15 MB/s (which isn't even possible here with my connection, nor at the server I'm uploading to).

Then at 100%, it waits a while, and then either a popup shows up if I want to overwrite the remote file (note that the file wasn't there yet before I started!) or it just reports the file as "completed" (transferred successfully) while in fact only the first MB or so has been uploaded.

If I try this with even larger files, for example 300 MB, the same thing happens: progress bar rapidly runs from 0% to 100% in a few seconds. While this is happening I can in fact hear my harddisk rattling like crazy, so I believe it is actually reading the entire 300 MB from the file. The upload speed it reports is like 50Mb/s or something.

I don't know what FileZilla does with the data, but apparently it somehow thinks the data is uploaded, while it is in fact not (maybe it's cashed in some strange way or something?).

Some facts:
- I've seen this happening in normal plain FTP mode as well as FTPES
- it happens on different servers
- it doesn't happen ALWAYS, although I feel it does happen more frequently on some servers than others
- it seems to happen especially frequently within the first few files in a session, when I drag & drop a lot of files to upload

Any suggestions?

Note that I can provide a test login to an FTP server on which this problem occurrs frequently, however I'd rather not post that in public here. Please PM me if you want one.

[botg]

The socket send buffer of FileZilla Server is a mere 256KB, so it cannot be buffering in FileZilla. It seems as if there's something locally on your machine that buffers all data. FileZilla starts sending as fast as possible and at the end of the transfer it waits for the server to acknowledge everything. Since something is buffering everything and only very slowing relaying it, FileZilla will eventually detect a timeout and abort the transfer. It will then automatically try to resume, only to figure out that only some small part of the file has actually made it to the server.

Some of the possible causes:

• * Some badly written virus scanners
  * Network tuning programs
  * So-called internet accellerators

[Henkie]

Hey, thanks a lot! I'll investigate this further, but I am actually getting the same problem on different machines.

• * Some badly written virus scanners

I'm only using Avira Antivir, and not even the resident (running-continuously-in-background-scanning-everything-you-do) part.

• * Network tuning programs
  * So-called internet accellerators

Certainly not using any of those.

I am however using a firewall, Outpost Firewall Pro x64 (gave full access to FileZilla though, and disabled all features except the firewalling part).

Any idea if either of these two programs are known to cause such issues? (neither occur to me as badly written crapware, have been a happy user of both for quite a while, but of course I don't know them inside out).

[boco]

Are you using a proxy of some sort?

[Henkie]

Are you using a proxy of some sort?

Nope.

[jpinkerton]

You are not alone! I actually came here as a last ditch effort before just dumping File-Zilla.
I LOVE FZ, have recommended it for a LONG time. I have all my sites organized, and sorted, and it's EASY AND QUICK.
This bug has been plaguing my experience for several releases. I keep updating hoping it's going to resolve the issue, and it doesn't.

This is happening to me on Windows XP desktop at work, Windows 7 desktop at home, and Windows XP laptop at home. I KNOW it's not to one computer, I've even gone through a format/reinstall to update desktop to new hardware, and the issue is STILL there.

It is maddening, and it seems it is random/tied to a "session". If I close FZ and go back in, I'm good - until the next time it happens.

Glad I'm not the only one with this issue.

[jpinkerton]

Oh, and I'd estimate that this issue just started happening within the last 4-6 months. Hasn't EVER been an issue prior. I've just dealt with it rather than submitting a bug request proper, which I should've done from day 1.

Also: No firewall/AV/proxy here on any of the machines with the issue.

[Henkie]

Oh, and I'd estimate that this issue just started happening within the last 4-6 months. Hasn't EVER been an issue prior. I've just dealt with it rather than submitting a bug request proper, which I should've done from day 1.

Also: No firewall/AV/proxy here on any of the machines with the issue.

Now that you mention it, yes, I think it started here about half a year ago. Very rough estimation though, but it certainly wasn't like this always! And I didn't make any significant changes to any of my systems since.

[Henkie]

boco or botg (or any other devs?), would it help if jpinkerton and/or me would send you a log of a failing transfer with this problem? Where should we send it?

[boco]

boco or botg (or any other devs?)

To be clear, there is only one developer: botg. I am not.

would it help if jpinkerton and/or me would send you a log of a failing transfer with this problem?

Most probably logs aren't of much use, as the problem is not FileZilla or the server, but some software or device in between, a buffering/caching proxy maybe, or a CDN.

Where should we send it?

Normally you'd just post it, in

Code: Select all

tags.

[botg]

Do you use Antivir's WebGuard component? It's known to cause network performance issues.

[Henkie]

Most probably logs aren't of much use, as the problem is not FileZilla or the server, but some software or device in between, a buffering/caching proxy maybe, or a CDN.

Are you sure? Notice that jpinkerton reports the same problem, on several machines, without any antivirus/firewall/etc.

By the way, what's a CDN? (Google results in "content delivery network", not sure how I would use that in relation to uploading to FTP..? Well anyway I'm not using one, that's for sure )

Especially the fact that this started, well, somewhere last year (don't remember since which version exactly) makes me feel it's related to FZ. Can't be sure of course, but I really never experienced this problem earlier, and I didn't change any other parameters (like changing my PC/software/OS/server/anything) that I know of.

Actually, do you still have previous versions available for download? I could try and install them, and find out which version did not have this problem yet, and which one did, to pinpoint the possible change that may have caused this? (if the problem is indeed in FZ)

Do you use Antivir's WebGuard component? It's known to cause network performance issues.

No. I do have Antivir, but I'm never running the resident part (the realtime 'guard' stuff), I only use it to right-click on downloaded items and scan on demand. No background scanning or intercepting here.

[boco]

Actually, do you still have previous versions available for download?

Project page: http://sourceforge.net/projects/filezilla/files/, or http://download.filezilla-project.org.

[haydo]

I had a problem a bit like this one.....Might have even been the same fault. But it just fixed its self. I know thats no help to you.

I might have had a slightly different fault mind you..