Here’s a dump of info and context.
Hope some of it helps! 
So, yes!
Late last week in the process of returning the servers to a healthy state we noticed that VERY large SoundSets were jamming up the processing queue.
We picked an arbitrary number (100) and switched off processing for any SoundSets with more than this number of elements. This helped things get back on track. It is not actually clear however which particular aspect of a ‘large’ SoundSet it is that is most deleterious to the server. AND we have some other solutions that probably help the server when it hits a log jam anyway… so this limit MAY not be needed now anyway.
So, what we are going to do, is have another go processing all SoundSets with numbers of elements between 101 and 250 and watch carefully what happens and see if we can get some data. Maybe it is actually the total number of samples that really matters… or the total sample duration…?
Main consequence… you should see your SoundSet process soon (as soon as the server gets to it).
Additional kinda philosophical approach: the general concept of a SoundSet is that it is a single location or single encounter and the Moods are the different kinds of moods or phases within that location or encounter. So a SoundSet with more than 20 Moods and more than 100 Elements is kinda outside our original design concept of what a SoundSet is…
BUT the system DOES seem to usually cope with this kind of concept… but sometimes NOT. So we WILL probably put SOME kind of limit in there… once we work out what will actually make a difference.
Does that all make sense? Thought? 