Make users upload each file one by one, so they won't have to upload them all at once
if user uploads "1.jpg " today
clientlist=("1.jpg")
then tommorow "2.jpg"
clientlist=("1.jpg", "2.jpg")
#1 and 2 uploaded again
then day after "3.jpg"
clientlist = ("1.jpg", "2.jpg", "3.jpg")
# 1 2 3 all uploaded again
server has
1 1 1 2 2 3
and suppose I dont upload whole clientlist, but what if there is Internet connectivity issue and 2.jpg fails to be uploaded then server never gets that