FTP upload occasionally stops and starts over again from 0%

[tmcdos]

When uploading files to FTP server with RESUME support, sometimes transfer occasionaly starts over from 0% without interruption - simply rewinds.
This is strange for me - since if there is any error in communication,
TC should show an alert. But it silently begins upload from the very
beginning. There is nothing interesting in the log file, though.

----------
Connect to: (15.01.2007 10:22:59)
hostname=upl.stg49.ifolder.ru
username=
startdir=
upl.stg49.ifolder.ru=89.108.65.214
220 ProFTPD 1.3.0 Server (ProFTPd server) [89.108.65.214]
USER ivo_gelov@gmx.net
331 Password required for ivo_gelov@gmx.net.
PASS ***********
230 User ivo_gelov@gmx.net logged in.
SYST
215 UNIX Type: L8
FEAT
211-Features:
MDTM
REST STREAM
SIZE
211 End
Connect ok!
PWD
257 "/" is current directory.
Get directory
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (89,108,65,214,208,186).
LIST -la
150 Opening ASCII mode data connection for file list
Download
Waiting for server...
226 Transfer complete.
TYPE I
200 Type set to I
SIZE Ku4ek.part2.rar
213 15006320
PASV
227 Entering Passive Mode (89,108,65,214,215,144).
APPE Ku4ek.part2.rar
150 Opening BINARY mode data connection for Ku4ek.part2.rar
Upload: 38 849 180 bytes, 30.4 kbytes/s
226 Transfer complete.
Copied (15.01.2007 10:39:24): G:\2\Ku4ek.part2.rar -> ftp://upl.stg49.ifolder.ru/Ku4ek.part2.rar 38 849 180 bytes, 41.0 kbytes/s
Get directory
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (89,108,65,214,200,45).
LIST -la
150 Opening ASCII mode data connection for file list
Download: 377 bytes
Waiting for server...
226 Transfer complete.
OFFLINE
----------
Connect to: (15.01.2007 11:13:32)
hostname=upl.stg49.ifolder.ru
username=ivo_gelov@gmx.net
startdir=/
upl.stg49.ifolder.ru=89.108.65.214
220 ProFTPD 1.3.0 Server (ProFTPd server) [89.108.65.214]
USER ivo_gelov@gmx.net
331 Password required for ivo_gelov@gmx.net.
PASS ***********
230 User ivo_gelov@gmx.net logged in.
SYST
215 UNIX Type: L8
FEAT
211-Features:
MDTM
REST STREAM
SIZE
211 End
CWD /
250 CWD command successful
Connect ok!
PWD
257 "/" is current directory.
Get directory
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (89,108,65,214,210,162).
LIST -la
150 Opening ASCII mode data connection for file list
Download
Waiting for server...
226 Transfer complete.
TYPE I
200 Type set to I
PASV
227 Entering Passive Mode (89,108,65,214,210,169).
STOR Hora.part1.rar
150 Opening BINARY mode data connection for Hora.part1.rar
Upload: 12 240 383 bytes, 1.4 kbytes/s, 4:34 h
PASV
226 Transfer complete.
PASV
227 Entering Passive Mode (89,108,65,214,236,213).
STOR Hora.part1.rar
150 Opening BINARY mode data connection for Hora.part1.rar
Upload: 58 584 063 bytes, 1.1 kbytes/s, 4:01 h
Get directory
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (89,108,65,214,221,196).
LIST -la
150 Opening ASCII mode data connection for file list
Download
Waiting for server...
226 Transfer complete.
TYPE I
200 Type set to I
SIZE Hora.part1.rar
213 58584576
PASV
227 Entering Passive Mode (89,108,65,214,222,111).
APPE Hora.part1.rar
150 Opening BINARY mode data connection for Hora.part1.rar
Upload: 100 000 000 bytes, 31.4 kbytes/s
226 Transfer complete.
Copied (15.01.2007 12:30:37): G:\2\Hora.part1.rar -> ftp://upl.stg49.ifolder.ru/Hora.part1.rar 100 000 000 bytes, 60.5 kbytes/s
Get directory
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (89,108,65,214,224,140).
LIST -la
150 Opening ASCII mode data connection for file list
Download: 458 bytes
Waiting for server...
226 Transfer complete.
OFFLINE
----------
Connect to: (15.01.2007 12:41:08)
hostname=upl.stg49.ifolder.ru
username=ivo_gelov@gmx.net
startdir=/
upl.stg49.ifolder.ru=89.108.65.214
220 ProFTPD 1.3.0 Server (ProFTPd server) [89.108.65.214]
USER ivo_gelov@gmx.net
331 Password required for ivo_gelov@gmx.net.
PASS ***********
230 User ivo_gelov@gmx.net logged in.
SYST
215 UNIX Type: L8
FEAT
211-Features:
MDTM
REST STREAM
SIZE
211 End
CWD /
250 CWD command successful
Connect ok!
PWD
257 "/" is current directory.
Get directory
TYPE A
200 Type set to A
PASV
227 Entering Passive Mode (89,108,65,214,249,220).
LIST -la
150 Opening ASCII mode data connection for file list
Download
Waiting for server...
226 Transfer complete.
TYPE I
200 Type set to I
PASV
227 Entering Passive Mode (89,108,65,214,249,247).
STOR Hora.part2.rar
150 Opening BINARY mode data connection for Hora.part2.rar
Upload: 3 700 223 bytes, 496 bytes/s, 34:21 h <== Here it was rewinded, so I pressed CANCEL
PASV
227 Entering Passive Mode (89,108,65,214,233,54).
STOR Hora.part2.rar
150 Opening BINARY mode data connection for Hora.part2.rar
Upload: 780 799 bytes, 404 bytes/s, 24:39 h
PASV
227 Entering Passive Mode (89,108,65,214,244,88).
STOR Hora.part2.rar
150 Opening BINARY mode data connection for Hora.part2.rar
Upload: 826 368 bytes, 1.6 kbytes/s, 10:33 h
Cancel pressed!
Upload: 826 367 bytes, 752 bytes/s, 17:52 h
Cancel pressed!
Get directory
TYPE A
226 Transfer complete.
PASV
227 Entering Passive Mode (89,108,65,214,251,5).
LIST -la
150 Opening ASCII mode data connection for file list
Download
Waiting for server...
226 Transfer complete.

[ghisler(Author)]

Strange, I have never seen this problem.

Can you give me step by step instructions what you did, e.g.
1. Connect to server
2. Go to directory containing file xyz
3. Upload file abc
etc.

Thanks!

[tmcdos]

Hi. I'm not sure, but I think that this behaviour occurs mostly on slow connections. My connection is about 300 KB/s, but uploading to the given server (www.ifolder.ru) is no faster than 30 KB/s.
May be latency is also important ?
So, from the beginning. I've an account on WWW.IFOLDER.RU (this is russian site, but I'm not russian guy - only speak little russian). They give me ability to upload files by FTP, but with a special formula - I request FTP access, they give me temporary login, which is valid for 24 hours, and then I can upload my files. So, if you
want to do some tests (and if you can not understand russian), then I should first prepare working login, and provide you with the information.
Then:
1. I connect to FTP server
2. It show my home directory, which is always empty, since login is just created (and temporary)
2. I start upload (usually 80-100 MB files).

If connection is good, then with 1-2 interruptions and resumes I'm able to upload the file. But if connection is slow, sometimes it spontaneously rewinds and starts from the beginning, instead of stop and allow me to do RESUME. I noticed that, because I watched from time to time on the progress indicator - and it shows 20%, then 40%, then 59%, and suddenly 10%

This may be not enough to discover the "error", if I can provide anything else - please tell me.

Thanks.

[ghisler(Author)]

So, if you want to do some tests (and if you can not understand russian), then I should first prepare working login, and provide you with the information.

Yes, it would be nice if I could do some tests. I think that I have found the problem, but it would be nice to be able to test the fix. Thanks for your help!

[tmcdos]

Hi.
Since the login information from WWW.IFOLDER.RU is valid only for 24-hours, and then I should request a new login - could you tell me how can I send the login information to you as soon as I have it ?

[ghisler(Author)]

Please contact me by e-mail to beta at ghisler dot com, so we can discuss this and find a good time for testing this. Please don't send me the account data yet! Thanks!

[ghisler(Author)]

Does anyone still have this error?

[ono]

Yes! I still have this error..... It is just driving me crazy today. I need to put some file on FTP server where I have terribly slow link today.

Using passive mode. When I try to resume, and during resume transfer connection gets broken, TC starts upload of the file from the BEGINNING!

This is total riot... as often it starts upload again of 100MB file, so I loose couple of hours.

Christian please fix it.

Best regards.

[ghisler(Author)]

Unfortunately I cannot reproduce it.

Can you send me a log of the transfer, please?

Any idea why the transfer stops?

[ghisler(Author)]

2tmcdos
2ono
Can you try to reproduce it now, please? I added more code to ensure that resume should never restart from the beginning, but I cannot say whether it will work in your specific situation or not. I don't know any servers which drop the connection, so I have to simulate it by unplugging the LAN cable, or by blocking the connection in my desktop firewall...

[latalik]

2tmcdos
2ono
Can you try to reproduce it now, please? I added more code to ensure that resume should never restart from the beginning, but I cannot say whether it will work in your specific situation or not. I don't know any servers which drop the connection, so I have to simulate it by unplugging the LAN cable, or by blocking the connection in my desktop firewall...

I still keep having this error. Unfortunately I do not have the ftp logs anymore. I will send them when The error happens again.

[ghisler(Author)]

Do you get this in a background or foreground transfer?

I can send you a special version which creates full logs also of the background transfers if you use that.

[latalik]

I usually upload in the background. I thought even the background transfer writes to the log, but never checked it. Please send me the version to latalik at gmail.

Cheers and thanks, Martin

Do you get this in a background or foreground transfer?

I can send you a special version which creates full logs also of the background transfers if you use that.

[msiivola]

I don't know if this belongs to this thread, but I have now seen TC 7.01 ftp download from my own server using Serv-U 6, to continue over 100%, meaning that it continues to download God knows what. I downloaded them a couple of times to verify that the error really exists consistently, and it did. The files are some hundred megabytes. CuteFTP downloads them correctly.

[ghisler(Author)]

What was different in the final file? Maybe the server doesn't correctly support the REST command (restart download) and started from the beginning?