MongoMem, a Python tool, by Wish Tech team:
Today, we’re releasing the first of these tools, MongoMem. MongoMem
solves the age-old problem of figuring out how much memory each
collection is using. In MongoDB, keeping your working set in memory
is pretty important for most apps. The problem is, there’s not
really a way to get visibility into the working set or what’s in
memory beyond looking at resident set size or page faults rate.
Original title and link: MongoMem: Memory Usage by Collection in MongoDB ( ©myNoSQL)