MongoDB 3.x – Maximum Oplog Size
In the official MongoDB documentation, it is said that the maximum size for oplog is 50GB. With 5 years of Oracle database experience, I developed the bad habit of trusting official documentation entirely. Following the procedure to resize the oplog on my laptop, I was able to resize it to 60GB instead.
my_rs_1:PRIMARY> rs.printReplicationInfo() configured oplog size: 61440MB log length start to end: 1568secs (0.44hrs) oplog first event time: Sun Jan 29 2017 17:55:26 GMT+0000 (GMT) oplog last event time: Sun Jan 29 2017 18:21:34 GMT+0000 (GMT) now: Sun Jan 29 2017 18:25:29 GMT+0000 (GMT)
I have resized it to 60GB instead! 🙂
Working with MongoDB for the last 3 months has made me realised a lot of things that Oracle DBA has taken for granted. Things that is supposed to work the way it is documented seems to be a bonus instead of being a requirement.
P.S: On the hindsight, I believe the 50GB upper bound only applies for the default 5% and not the maximum configurable size.
Hope this helps!