MongoDB replica set and db.stats()


We just added a node to our replica set. After the node's state switched to SECONDARY, I do

use obs

on both the PRIMARY node and the new SECONDARY.

               PRIMARY    SECONDARY
"collections" :  19          18
"views" :        0            0
"objects" :    70926        70409

Why are numbers of objects and collections different?

Best Answer

OK we found why there is a discrepancy.

We were able to list the collections on the secondary node with

show collections

From there, I realized the extra collection on the primary was system.profile (I'd forgotten I'd turned on the profiler) and it's 517 documents accounted for the different object counts from db.stats()