Picking up Pace

The Aperture to Lightroom migration has picked up the pace. Yesterday morning, after about 28 hours, progress sat at 17%. This morning after an interval of 24 hours, it was 75%.  

So what happened? I closely monitored progress of the migration and when the pace slowed I did a restart. After the restart at 33% the pace seemed to remain fairly consistent so no further restarts were done until 75% which is when I woke up this morning and saw that the pace had slowed over night. 

So why would restarts help? A gradual slowdown of progress suggested a bug in the migration program, specifically a memory leak. The usual fix for this type of problem is to restart the program. This appeared to work as pace after each restart was noticeably improved. 

So why at 33% and above was the pace fairly stable?  This could point to another problem: a design lacking scalability. In a scalable design one would expect that if it took 10 seconds to process 10 records, it would take 100 seconds to process 100 records. In a non scalable design it might take 1,000 seconds to process the 100 records. Thus the suspicion that as the number of photographs remaining got smaller the 1,000 seconds got closer to the expected 100 seconds.  

So while it looks like the migration will complete in advance of the previously estimated 7 days, three questions remain:

• File transfer errors:
  After my second and third restart the migration program reported a number of files that were not moved.  It claimed they were incompatible, unsupported.  Yet they were JPEG files, which are supported.
• Number of files:
  The number of files on disk (about 60,000) is larger than the number of files in the Aperture library (about 48,000).  I’ll need to rationalize this to make sure I’ve moved everything over. It is possibly explained by having shared the same file structure between Aperture and Lightroom and thus those additional photographs are already in Lightroom.  
• The meaning of 1%
  I can watch the number of photographs in my library increase with the progress of the migration.  Tracking this number it looks like each percentage point is about 150 photographs.  If that’s correct then 100% implies 15,000 photographs which is about one-third the number reported in the Aperture library.  Either I have a third total number of photographs to deal with or the latter percentages of the migration will be disproportionately large or a percent is representative of some other countable item.   

Configuration Menu

Options Menu