FTP Upload replacement

[Lothar Kimmeringer]

I think the problem is there are delays where nothing is being
transmitted. I know this from observation, not from analysis of the
protocol.

This is a bit dependent on the network-connection because every
file-transfer needs the establishment of a new network-connection
(a new data-channel). So if you have many many small files, WEBDAV
using HTTP/1.1 and keep-alive connections can gain advantage over
FTP because the time it needs to establish a new connection might
take longer than the time to transfer the "huge" amount of data
the HTTP-request and -response-header consist of.

SFTP can be a good alternative because it's using the established
SSH-connection and just opens another "logical" connection (called
channel) to transfer the file. The SSH-protocol also supports
compression (but needs to be activated explicitly sometimes).


Regards, Lothar
--
Lothar Kimmeringer E-Mail: (e-mail address removed)
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Always remember: The answer is forty-two, there can only be wrong
questions!

 

[Martin Gregorie]

odd. I am experiencing this with Unix BSD 4. Do you have a choice of
FTP servers?

How is your FTP server launched and how many process copies or threads
does it support?

There is a version of the FTP server that's launched by xinetd and, if
its service descriptor limited it to spawning just one or two copies, you
may well see this type of problem. I'd expect that FTP servers designed
to run as boot-time daemons would do rather better.

 

[Arne Vajhøj]

If files were bundled into compressed archives and uploaded, you at
least get rid of the per-file handshaking.

Sure.

But that is still independent of FTP, HTTP or Foobar transport
protocol.

Arne

 

[Arne Vajhøj]

It's a standard for a Message Transfer System that is quite
much older than SMTP and covers much more than the original
SMTP-standard. But, yes, it's some kind of email-system that
is still quite common for the transfer of EDI-messages.

Ah. So it was EDI over X.400. I was just puzzeled over
how email and file transfer fitted together.

Arne

 

[Roedy Green]

But that is still independent of FTP, HTTP or Foobar transport
protocol.

Not necessarily. If, for example you had several threads going at
once, so you kept the channel busy, you would not waste as much time
waiting. FTP Voyager improves FTP that way by getting several
independent FTP transfers going at a time.
--
Roedy Green Canadian Mind Products
http://mindprod.com

"For reason that have a lot to do with US Government bureaucracy, we settled on the one issue everyone could agree on, which was weapons of mass destruction."
~ Paul Wolfowitz 2003-06, explaining how the Bush administration sold the Iraq war to a gullible public.

 

[Roedy Green]

How is your FTP server launched and how many process copies or threads
does it support?

I think it runs all the time. I can use it with FTP Voyageur, so I
think it can probably handle at least 3 threads.

I have no control of the software on my server. This is supposed to
change.
--
Roedy Green Canadian Mind Products
http://mindprod.com

"For reason that have a lot to do with US Government bureaucracy, we settled on the one issue everyone could agree on, which was weapons of mass destruction."
~ Paul Wolfowitz 2003-06, explaining how the Bush administration sold the Iraq war to a gullible public.

 

[Arne Vajhøj]

Not necessarily.

I think it is.

If, for example you had several threads going at
once, so you kept the channel busy, you would not waste as much time
waiting. FTP Voyager improves FTP that way by getting several
independent FTP transfers going at a time.

That is not changing the protocol. That is changing the
application logic.

Arne