Graham,
I have uses Ics ftp server with inews, in this case inews was configured to
act as a ftp client and would ftp nmsl as each item in the rundown changed
(I called it delta change). Inews would also use ftp command to delete files
as journalists deleted items. So Polling is NOT required, however some
method to purge files and force inews to resend is needed when the two
systems get out of sync. Deletenig all files and doing a "story renumber
all" solves most of thes problems. I just rembered... inews opened too many
client connections so make sure the ftp server drops the connection after a
period of inactivity.
The other alternative is to use MOS but inews mos gateway licences are very
expensive.
Robert
www.oneboxtvstudio.com
----- Original Message -----
From: "Graham (Deephaven)" <gra...@deephaven.co.uk>
To: "ICS support mailing" <twsocket@elists.org>
Sent: Sunday, October 11, 2009 7:47 AM
Subject: Re: [twsocket] FTP Client Delay - take 2
Thanks for all your comments. The FTP server is not mine and cannot be
changed so if anything can be changed it has to be in the FTP client.
The polling is not the problem, one LIST command returns a list of items
and attributes. The problem is when the server marks every item as changed
that client has to download every item to determine if the change is
valid.
If it helps, I'll tell you that the FTP client is a teleprompter and the
server is the Avid/iNEWS newsroom system.
So it appears that the delay is probably caused by the opening and closing
of the data port connection. One thought I have had is that when I was
working with Delphi TClientSocket and connecting / disconnecting to the
TServerSocket, I found that I could not disconnect and then re-connect
without inserting a delay. However if I created an array of TClientSockets
and hop on to the next one after each disconnect, I did not need any
delay.
Could something like this be done in the FTP client. I haven't yet delved
too closely into the source code, but I assume that somewhere it uses the
ICS socket for the data channel. Would it work if it were changed to an
array of sockets?
Graham
----- Original Message -----
From: "Francois PIETTE" <francois.pie...@skynet.be>
To: "ICS support mailing" <twsocket@elists.org>
Sent: Saturday, October 10, 2009 8:44 AM
Subject: Re: [twsocket] FTP Client Delay - take 2
Hello Graham,
Unfortunately in this instance 200mS is a problem. The client is
performing a LIST every 3 seconds on the server. There may be 300-400
files in the list. All of a sudden the server flags every file as
changed and the client has to download every file to see if the change
is valid. So now 200mS per RETR accumulates to a significant time.
I don't know how far you can control both client and server side, but if
you can change server side, probably it would be much better to design a
specific server program instead of using FTP protocol.
FTP protocol is slow by design (design of the protocol, not design of
ICS). There are two connections: one for control and one for data. Each
file transfert needs a new data connection and this takes time to setup
and close properly.
More, I understand you are doing a polling which is both slow and imposte
an important load on the server.
I suggest you design a simple server which would use Windows API to be
notified for file changes in the folder your are monitoring, send the
notification to the client which would download the files using the same
channel as the control channel, or even use multiple channels to download
several files at once.
Regards,
--
francois.pie...@overbyte.be
The author of the freeware multi-tier middleware MidWare
The author of the freeware Internet Component Suite (ICS)
http://www.overbyte.be
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