MongoDB memory utilization increases upto 92% and cache usage is also more than 80%. The database stats are as below:

db.stats(1024)

{ "db" : <"CONFIDENTIAL">, "collections" : 555, "objects" : 20797991, "avgObjSize" : 1123.3038404045853, "dataSize" : 22814905.432617188, "storageSize" : 9519780, "numExtents" : 0, "indexes" : 2612, "indexSize" : 2280272, "ok" : 1}