[Info-vax] SFTP hang - from VMS to Windows

[Jan-Erik Soderholm]

GerMarsh wrote 2013-02-25 13:13:
> Anyone seen anything like this?
>
> We get intermittent hangs during file transfers - nothing consistent
> about which file will be affected nor their sizes.
>
> Windows is running an OpenText (Hummingird) server. VMS is TCPIP
> Services V5.6 - ECO 2.
>
> The "hang" can be kicked into life by trying an FTP connection to the
> same server!
>
> The logfile shows something like this: sftp> ascii
>
> sftp> lcd /$1$DGA22/DATA/USERS/PC_SCHEDULE
>
> /$1$DGA22/data/users/pc_schedule sftp> cd /er_pc_root
>
> /ER_PC_Root sftp> put PC_ASCII_FILE.DAT
>
> PC_ASCII_FILE.DAT     |   96kB |  96.0 kB/s | ETA: 00:00:23 |   4%
> PC_ASCII_FILE.DAT     |  288kB | 144.0 kB/s | ETA: 00:00:14 |  12%
> PC_ASCII_FILE.DAT     |  384kB | 128.0 kB/s | ETA: 00:00:15 |  16%
> PC_ASCII_FILE.DAT     |  576kB | 144.0 kB/s | ETA: 00:00:12 |  24%
> PC_ASCII_FILE.DAT     |  704kB | 140.8 kB/s | ETA: 00:00:11 |  29%
> PC_ASCII_FILE.DAT     |  864kB | 144.0 kB/s | ETA: 00:00:10 |  36%
> PC_ASCII_FILE.DAT     |  1.1MB | 155.4 kB/s | ETA: 00:00:08 |  45%
> PC_ASCII_FILE.DAT     |  1.3MB | 168.0 kB/s | ETA: 00:00:06 |  56%
> PC_ASCII_FILE.DAT     |  1.5MB | 174.2 kB/s | ETA: 00:00:04 |  65%
> PC_ASCII_FILE.DAT     |  1.8MB | 185.6 kB/s | ETA: 00:00:02 |  77%
> PC_ASCII_FILE.DAT     |  2.1MB | 192.0 kB/s | ETA: 00:00:01 |  88%
> PC_ASCII_FILE.DAT     |  2.3MB | 194.7 kB/s | ETA: 00:00:00 |  97%
> PC_ASCII_FILE.DAT     |  2.3MB | 182.2 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 169.1 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 157.9 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 148.0 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 139.3 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 131.6 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 124.6 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 118.4 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 112.8 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 107.6 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB | 103.0 kB/s | ETA: 00:00:00 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB |  98.7 kB/s | ETA: 00:00:00 |  99% . .
> . PC_ASCII_FILE.DAT     |  2.3MB |   3.1 kB/s | ETA: 00:00:06 |  99%
> PC_ASCII_FILE.DAT     |  2.3MB |   3.1 kB/s | TOC: 00:12:46 | 100% sftp>
> quit
>
> The transfer sits at 99% with no throughput - and the associated average
> rate decreasing.
>
> There is nothing significant in the logs on the Windows side but I don't
> think the problem lies on the VMS end either.
>
> Networks support also state that there is no contention on the network
> during these incidents.
>
> The process is not really hanging as it is dutifully outputting its
> progress. Just sits in LEF state most of the time. Two BG devices in use
> but I would expect that. No process or pooled quota issues either.
>
> As ever, any pointers gratefully received!
>
>
>
>
> Gerald.
>

Just to clearify... :-)

What made the process tip over frm 99% to 100% (and finish) was that
you opened a second sftp session to the same Windows server?

A second sftp session from the same VMS box to some *other*
(Windows or not) server does not have this effect?

What if one opens a second sftp session against the same Windows
server but from some *other* client host (OpenVMS or not) ?

As usual, testing different scenarios helps understand where (at
what host) the hang actualy sits.

Jan-Erik.