Picking the right value for BlockSize is very important. I have encountered an over one order of magnitude difference in transfer rates using different values for BlockSize when using Net::FTP.
I think the default value is 1K. I tried powers of 2 from 1K up to 64K. For me a BlockSize value of 4K worked best for transferring ~200Kb files from a Windows NT system to a Sun Solaris system over a 100BaseT switched network. I was surprised to see that the larger values were sometimes just as slow as the smaller values. The transfer speed decreased as I tried BlockSize values further away from 4K in either direction. I would suggest that you try various values to see what works best for you. To specify a BlockSize, add it to your Net::FTP->new call: $ftp = Net::FTP->new($host, BlockSize => $::FTP_BLKSIZE); Graham Barr wrote: > When transfering in ASCII mode (the default) Net::FTP will be slower > due to doing the CRLF translation. But transfering in binary mode > should be comparable. Increasing the transfer blocksize should > also help. > > Graham. > > On Thu, Apr 18, 2002 at 11:17:24PM -0400, Terrence Brannon wrote: > > Hi Brian, > > > > You might put this question on the [EMAIL PROTECTED] list as > > Net::FTP is maintained by Graham Barr and you are raising an issue > > specific to his module, not my application layer on top of it. > > > > I am Cc'ing this message there > > > > brian_turner_98006 writes: > > : When I do an ftp using: > > : `ftp -i -n $dbshost << 'EOF' > > : user $remoteuser $remotepwd > > : get $remotefile $localfile > > : quit > > : EOF`; > > : > > : It takes an average of about 0.024 seconds/request > > : > > : However, when I try it with > > : > > : $ftp = Net::FTP->new($dbshost,Debug => 0); > > : $ftp->login($remoteuser,$remotepwd); > > : > > : then loop with: > > : > > : $ftp->get($remotefile, $localfile) > > : > > : It takes about 1.3 seconds/request. > > : > > : Version info: > > : > > : Summary of my perl5 (revision 5.0 version 6 subversion 0) > > : configuration: > > : Platform: > > : osname=solaris, osvers=2.6, archname=sun4-solaris > > : uname='sunos rmdsun01 5.6 generic_105181-21 sun4u sparc > > : sunw,ultra-4 ' > > : > > : I'm assuming that the login stays connected when I use Net::FTP so > > : this doesn't make sense to me. Spawning a process+connecting should > > : be slower. Any suggestions? > > : > > : FWIW, my application requires a large number of small file transfers > > : at random intervals. > > : > > : (I didn't see that Net::FTP was modifed in 5.6.1 based on > > : http://www.perldoc.com/perl5.6.1/Changes.html, but I'm open to > > : upgrading if there's a reasonable chance of fixing this issue) > > : > > : Thanks, > > : > > : Brian > > : > > : > > : > > : > > : > > : ------------------------ Yahoo! Groups Sponsor ---------------------~--> > > : Buy Stock for $4 > > : and no minimums. > > : FREE Money 2002. > > : http://us.click.yahoo.com/k6cvND/n97DAA/ySSFAA/ndFolB/TM > > : ---------------------------------------------------------------------~-> > > : > > : To unsubscribe from this group, send an email to: > > : [EMAIL PROTECTED] > > : > > : > > : > > : Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > > : > > : > > : > > -- James D. White ([EMAIL PROTECTED]) Department of Chemistry and Biochemistry University of Oklahoma 620 Parrington Oval, Room 313 Norman, OK 73019-3051 Phone: (405) 325-4912, FAX: (405) 325-7762
