Eric on 10 Jul 2006 14:01:52 -0000 |
I've encountered a file transfer problem that is quite perplexing - and I'm at a loss to identify the cause. Part of the problem is that it's random and it's complex (a number of variables are involved) and therefore hard to narrow down to a single failure point. The basic scenario is this: I have a shell script that uses curl commands to retrieve multiple files from two ftp servers. The host for this is a rented box that I do not have root or physical access to. I do not have root or physical access to the ftp server either for that matter... I'm just a user/developer tryin' to bring the data home :-) The script ran on a shared box for several months but was moved to it's own box with a new IP on Thursday. On Friday the random failures began.. some initial portion of the file would download at normal speed then the rate would drop to zero bytes per second and stay there. If the script is re-run it may download that file just fine only to fail on the next download. Also, the size of the initial download appears random too - one was 292 kB, the next was 1.9 Meg... etc. There is a log fragment at the bottom of this email showing the relevant part (the output of the curl command). Other factors I've considered: The transfer randomly fails if we use ftp from the command line too - it's not just curl For security reasons, the ftp server must have the IP of the requestor on file - and it does. Otherwise, we could not even log it. The failure can be from either of the ftp servers - although they are on the same domain they are separate host names. Now if anybody has seen something similar or has any ideas on how to further troubleshoot this I'd be very grateful. Keep in mind that it's been working like clockwork since March or April so it's not the programmer's fault :-D Thanks. Eric Our host: # uname -a Linux host.xxxxxxxxx.com 2.6.9-34.EL #1 Wed Mar 8 00:07:35 CST 2006 i686 athlon i386 GNU/Linux Log fragment showing how it fails: ----- curl -n $DATAURL1 > $DATAFILE1 retrieving BR_20060710_013000__dat_full_.zip % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 24.1M 0 1460 0 0 1283 0 5:29:00 0:00:01 5:28:59 1283 0 24.1M 0 168k 0 0 106k 0 0:03:53 0:00:01 0:03:52 371k 2 24.1M 2 684k 0 0 264k 0 0:01:33 0:00:02 0:01:31 470k 4 24.1M 4 1166k 0 0 319k 0 0:01:17 0:00:03 0:01:14 462k 4 24.1M 4 1199k 0 0 219k 0 0:01:52 0:00:05 0:01:47 277k 4 24.1M 4 1199k 0 0 185k 0 0:02:13 0:00:06 0:02:07 225k 4 24.1M 4 1199k 0 0 160k 0 0:02:33 0:00:07 0:02:26 175k 4 24.1M 4 1199k 0 0 141k 0 0:02:54 0:00:08 0:02:46 89742 4 24.1M 4 1199k 0 0 126k 0 0:03:15 0:00:09 0:03:06 5781 4 24.1M 4 1199k 0 0 114k 0 0:03:35 0:00:10 0:03:25 0 4 24.1M 4 1199k 0 0 104k 0 0:03:56 0:00:11 0:03:45 0 4 24.1M 4 1199k 0 0 98511 0 0:04:17 0:00:12 0:04:05 0 4 24.1M 4 1199k 0 0 91188 0 0:04:37 0:00:13 0:04:24 0 4 24.1M 4 1199k 0 0 84879 0 0:04:58 0:00:14 0:04:44 0 . . [five hours later we see.... Current Speed is stuck at zero] . 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:03:55 99:56:12 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:03:56 99:56:11 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:03:57 99:56:10 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:03:58 99:56:09 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:03:59 99:56:08 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:04:00 99:56:07 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:04:01 99:56:06 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:04:02 99:56:05 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:04:03 99:56:04 0 4 24.1M 4 1199k 0 0 67 0 4d 09h 5:04:04 99:56:03 0 -- ------------------------------------------------------------------------ # Eric A Lucas # ------------ # "Oh, I have slipped the surly bond of earth # and danced the skies on laughter-silvered wings... # -- John Gillespie Magee Jr. ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
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