I’ve discovered a bug in the Cellprofiler 2.1.0 (rel 0c7fb94) software. If I analyse just one plate of data (1536 images), everything works fine - cellprofiler spawns several workers that each do their work. However, if I import several plates at the same time (using the exact same analysis profile) and use grouping to group each plate based on the metadata, Cellprofiler spawns the correct number of workers but only utilises one worker per plate. I.e. If I try to analyse two plates at the same time, I’ll have twelve workers active, but only two of them doing anything. I can see in the log output that the workers are there and they are listening for input but they never seem to receive any work to do. The IDs of the active workers seem random, i.e. sometimes it’s worker0 and worker5 that are active, sometimes others.
Bug seen under Windows 7 x64, Windows Server 2008 R2 x64, and Windows 8.1 x64.