MongoDB: why does a DB with 0 connections still get "commands" and "getMores"? I'm in the process of migrating an old mongoDB database.
Before shutting down the old one, I want to make sure nothing is still writing to it or reading from it. Looking at Compose's MongoDB classic monitoring tool, the graph indicates 0 inserts, 0 queries, 0 updates and 0 deletes BUT, also a steady stream of "getMores" and "commands".

I assume the commands must be internal processes of MongoDB, but which ones? What's going on? Also, from the bit of search I've made, it seems that getMores have something to do with cursors, what internal process would be using cursors?
Since this is a replica set, the getMores are likely due to replication. Even with no write activity, replica set members will poll for updates on the oplog.rs collection. 

The commands are probably related to monitoring (for example, serverStatus to get the opcounters that are being plotted).