[JSch-users] Enormous traffic when uploading file to non-empty folder

[Milano N. <dra...@gm...>]

OK, now I feel embarassed and stupid for not noticing earlier that in my
code there is hidden the *ChannelSftp.ls* call. No idea why. It's been
there since beginning of the app. It is called once when new file
abstraction is requested and once for any other operation (e.g. requesting
an OutputStream from the abstraction).

*Let's do the math now:*
If you have about 6400 files in the upload directory, it means about 1,5 MB
of data to download if you want to list it. And it can take up to two
minutes (120 seconds) to download such data depending on your connection.

So if you want to *upload* one *4KB* file to the SFTP using streams, you
are going to *download 3MB* of useless data first, *wait* up to about *four
minutes* and then your file is downloaded. I'm not even speaking about the
fact the operation is going to fail if your connection is slow since you're
not going to simply download so much data on a bad connection.
Thanks to Lothar for pointing me to the right direction!