How can I see what iCloud Photos is uploading right now?

Question

I selected a large number of photos (and videos) across many different photo albums be uploaded by iPhoto (9.5.X) from my rMBP 15 (OS X 10.9.4) to several different streams (named by year 2003, 2004, 2005 ...). The number of photos would have been around 5000 and the videos would have been less than 50.
My problem is that the iCloud Photos component (the name of the component within the activity monitor) is perpetually uploading content but nothing is showing up within any of my devices subscribed to those streams - yet the network tab on activity monitor is showing 1-2 GB of data uploaded each day.
The first few streams contained most of the photos from the year (maybe 80%) but by the time it got to 2006 and 2007 it just shows 1 or 2 photos and nothing else.
I have a reasonable network connection 1Mb/s upstream and 20 Mb/s down and I have left the machine running 24x7 for many days at a time - all the time with activity monitor registering a large total network upload but nothing is showing within my streams on any of my devices including the rMBP that I sent the files from.
I have given up in my desire to upload the photos - I just want iPhoto to stop attempting to upload files as it is consuming all my upstream bandwidth and preventing me from using my internet connection - so much so that I have gone back to my old MBP.
I have looked within the console log application and can not find anything useful when filtering using the strings "iCloud" or "iPhoto".
Can anyone provide any suggestions as to how I can locate the files being attempted to be uploaded? Or how I can prevent them from being attempted to be uploaded?
As a last resort I am willing to purge files from my iPhoto library (by putting them on another storage system).

Answer 1

I have deleted all of the streams that I believed to be causing problems and it is still occurring.
I deleted all of the year based streams and several other older streams and it still did not help. It still attempted to upload 1GB of data last night.
I suspect that there may be a problem with photostream agent component. When I deleted the year based streams (which were all created from my rMBP) they failed to delete from any of my devices (iPhone, iPad) - which I believe is one of control points of iPhoto /iCloud.
To answer my original stated question I was able to track which files were originally being accessed iPhoto / photostream agent using this command
sudo dtrace -n 'syscall::open*:entry { printf("%s %s",execname,copyinstr(arg0)); }' | grep photo
which pointed me to a set of folders located here
/var/folders/n_/jvfrft450wz30sbn8sh6s9qm0000gn/T/com.apple.photostream-agent/ass et-Ntk5Aq
Is there someway that I can force the photostream agent to purge it's state or flush it's cache ...ie to force it to want to restart cleanly (ie forget about everything that it thinks that it needs to upload) without actually deleting every single photo that I have on my machine?