How do I check if an index is being used

Question

I have a mongodb replica set with a lot of databases, collections & indexes.

We did a lot of refactor and optimization and, of course, I have a lot of \"creative

Answer 1

The simplest solution to this is to use the mongodb inbuilt $indexStats

Using the Mongo console run -

db.collection.aggregate([ { $indexStats: { } } ])

Using PyMongo -

from pymongo import MongoClient
collection = MongoClient()[db_name][collection_name]
index_stats = collection.aggregate([{'$indexStats':{}}])

for index_info in index_stats:
    print index_info

Apologies for re-opening an old question. This shows up on the first page of google searches and the only answer is to use a snippet of unmaintained code.