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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">There’s more to the issue, than simply splitting the files among N workers.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">All the directories would need to transferred first. You wouldn’t want worker “D” trying to copy a file, before worker “C” was able to create the directory
to hold it.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">There is also the issue of hard links. Where would the inode information be kept, so that hard links can be detected, transferred; rather than replicating files
needlessly at the destination.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I’m sure that there has been many threads covering these issues in the past. It all comes down the development and testing costs, far outweigh the potential
gains.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">If there really any area that could regularly gain from multithreading, it would be on the sender side with checksums and compression.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The only time I’ve seen where some kind of threading would have help, is I was trying to transfer hundreds of gigabytes of data across a gigabyte link. My
SPARC servers couldn’t keep the pipe filled, until I stepped up a directory level and copied each of those directories as a separate rsync session.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> rsync-bounces@lists.samba.org [mailto:rsync-bounces@lists.samba.org]
<b>On Behalf Of </b>ameirh@gmail.com<br>
<b>Sent:</b> Wednesday, September 04, 2013 6:29 PM<br>
<b>To:</b> rsync@lists.samba.org<br>
<b>Subject:</b> Native Parallelization in rsync<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">I'm sure this is a topic that's come up plenty of times before, but is it possible to implement native parallelization in rsync? There are several blog posts listing workarounds,
but they are largely unideal.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">My initial thought would be that rsync could split up the file list across N workers; the incremental file list would still be generated as it does today, but can then be divided
evenly across a user-specified number of threads/processes that do the actual transfer of the files. I can think of several tweaks to this process, but I think this is a good starting point.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">I'm sure there are challenges with this approach that I'm not aware of, but it would be a great way to take advantage of free system resources and bandwidth, especially when
transferring thousands of files.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Is this something that's in the works or that can be in the works?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Thanks for the awesome project!<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">-Ameir<o:p></o:p></span></p>
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