in reply to Net::FTP Upload much slower than Dos prompt command ftp

I'd recommend Net::FTP::Throttle. What's most interesting for me is the way it enables you to experiment with different bandwidths. The documentation gives a starting bandwidth example of a MegabitsPerSecond => 2. I experimented and took it up to 6. It works for me, and it's superfast. 
#!/usr/bin/perl

use strict;
use warnings;
use Net::FTP::Throttle;

use constant HOST => 'ftp.cpan.org';
use constant DIR  => '/pub/CPAN';
use constant FILE => 'README';

my $ftp = Net::FTP::Throttle->new(
    HOST, 
    Debug     => 1, 
    Passive   => 1, 
    Timeout   => 1,
    Bytes_read => 8192,
    BlockSize  => 8192,
    MegabitsPerSecond => 6) or die "Couldn't connect: $@\n";

$ftp->login('anonymous');
$ftp->cwd(DIR);
$ftp->binary;
$ftp->get(FILE);
$ftp->quit;

[download]
Also, you adjust Bytes_read and BlockSize to meet your needs.

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Re^2: Net::FTP Upload much slower than Dos prompt command ftp
by Anonymous Monk on Jan 12, 2011 at 15:24 UTC
[reply]

      Thanks Marto, Monk, and Khen,

      I will try your suggestion tomorrow.

      The problem / slow thruput only when Uploading to FTP server, when download from server to local PC using Net::FTP no problem, the thruput of download same and closely same as DOS prompt command.

      It's interesting that NET::FTP introduces thruput problem in upload.


[reply]

        I believe the slowdown is caused by the default blocksize used (10k):

        ${*$ftp}{'net_ftp_blksize'} = abs($arg{'BlockSize'} || 10240);

        [download]

        You can easily test this hypothesis by supplying a parameter BlockSize => 4096 to the constructor.

        I'd step through 1024, 2048, 4096 etc. and see what difference if any that makes to your throughput.

        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority".
        In the absence of evidence, opinion is indistinguishable from prejudice.
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[d/l]
[select]
        Remember, also, that upload speed depends on the capabilites of your host or provider. For example, a common ADSL configuration would be 1.54 Megabits per second for downloads, whereas uploads would be 640 Kilobits per second. That might explain the difference in thruput:).
[reply]

        Hi Khen,


        my $ftp = Net::FTP::Throttle->new(
        HOST,

        ...

        Bytes_read => 8192,

        In above Net::FTP::Throttle, is there something like

        Bytes_write => 1024 or 2048 ?

        Since the issue is uploading only.

        -- Uploading the thruput is twice slower when using NET::FTP vs. Dos Prompt command ftp ftp.server.com 'put'

        -- Downloading: the thruput when using either NET::FTP or Dos Prompt command are closely same.

        The ftp server is on the WAN (in the cloud)

        Everything the same, configuration, settings, PC, and HW. The different is NET::FTP and Dos Prompt, and the time is about 10 minutes apart between these 2 scenarios, as 3mb file Upload with Dos Prompt it took about 2-3 minutes, and with NET::FTP it took 4-5.30 minutes each time. I did over 10 times.


        <Thanks everyone for help>
[reply]

        Hi Everyone,

        Thanks very much for yours input. I did try and found that adding BlockSize => 2518 (just right fit to 2 packets) and the Upload thruput of uploading 3mb now is around 82-94 sec, even better than Dos Prompt -

        By the way, ActivePerl does not have NET::FTP::Throttle

        Thanks!!!
[reply]

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