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RE: 5 uploads per second

From: Loren Kirkby <loren_at_how2share.com>
Date: Mon, 6 Oct 2003 14:49:02 -0700

Hi Peter,

That sounds like it might be the TCP Nagle algorithm. The Nagle algorithm
buffers outgoing data for better throughput. The buffering timeout is
usually around 200ms.

You may be able to disable the Nagle buffering (see setsockopt/TCP_NODELAY),
but that's usually not a good idea.

Does anybody know if other FTP clients have this problem?

Cheers,
Loren Kirkby

-----Original Message-----
From: curl-library-admin_at_lists.sourceforge.net
[mailto:curl-library-admin_at_lists.sourceforge.net] On Behalf Of Peter Stirzel
Sent: October 6, 2003 8:58 AM
To: curl-library_at_lists.sourceforge.net
Subject: Re: 5 uploads per second

Hi

Before I start:
Best wishes to you Daniel and to your family.
Enjoy your new life. My little daughter Sina is 16 weeks young,
so I prefer to screen through the mailing list between 1am and 5am ;-)

Switching to curl ....

I gathered some more information in order to find an easy
way to increase the number of uploads per second.

I am using the same easy handle for all transfers.
See below the CURLOPT_VERBOSE output.
What I have learned is that for every upload the cwd command
is performed and a new data connection port is opened.
This takes app. 200ms for each upload and I wonder if there
is a possibility to prevent this.

Otherwise I need to bundle my files.

Thanks

      Peter

-->Transfer file 1:
* About to connect() to 192.122.62.15:21
* Connected to 192.122.62.15 ((nil)) port 21
> USER guest
> PASS guest1
* We have successfully logged in
> PWD
* Entry path is '/home/guest'
> EPSV
> PASV
* About to connect() to 192.122.62.15:32875
* Connecting to 192.122.62.15 ((nil)) port 32875
* Connected the data stream with PASV!
> TYPE I
> STOR JC0003090513563500001
* Connection #0 left intact

-->Transfer file 2, reusing the same handle
* Re-using existing connection! (#0)
* Connected to [re-used] ((nil)) port 21
> CWD /home/guest
> EPSV
> PASV
* About to connect() to 192.122.62.15:32876
* Connecting to 192.122.62.15 ((nil)) port 32876
* Connected the data stream with PASV!
> TYPE I
> STOR JC0003090513563500002
* Connection #0 left intact

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Received on 2003-10-07