Watch keynotes and sessions from MongoDB.live, our virtual developer conference.

My mongodb cluster config server use too much memory


config use memory 7GB,and my server has other shading,collection local.oplog.rs has 164764738 records

configRS:SECONDARY> use local
switched to db local
configRS:SECONDARY> show tables;
me
oplog.rs
replset.election
replset.minvalid
startup_log
system.profile
system.replset
configRS:SECONDARY> db.oplog.rs.find().count()
164764738

Hi @11122

mongod going to use what you configured plus whatever it can use from the filesystem cache.

With WiredTiger, MongoDB utilizes both the WiredTiger internal cache and the filesystem cache.

Via the filesystem cache, MongoDB automatically uses all free memory that is not used by the WiredTiger cache or by other processes.

https://docs.mongodb.com/manual/reference/program/mongod/index.html#wiredtiger-options