Overwriting oplog

[Scott_78259 (Scott Dowd)]

Course M103. Chapter 2 - Replication. Local DB: Part 1

From 3:35 to the end of the presentation, the presenter shows output from:

• rs.printReplicationInfo()

He describes the “log length start to end” as being an estimate for the length of time before the log will start overwriting entries. My understanding is that all this field describes is the current length in time of the log - first transaction to last transaction.

Either I’m completely misunderstanding what he is saying in the video, or it would be a good idea for you to update the video for this module before the next class.

Thank you!

[007_jb (O Brown)]

I’m with you @Scott_78259 ! It’s the difference in time (secs and hours) between the bottom two entries, oplog first event time and oplog last event time as per documentation:

All it does is it takes the first and last entries in local.oplog.rs and gives a time difference which I find a bit moot. It doesn’t give you the option to exclude periodic noop (i.e. "op": "n") which runs every 10 seconds. I much prefer rs.printSlaveReplicationInfo().

It’s best to use the Report an Issue button located on the bottom-left corner of the course lecture page to report this issue. This way it goes directly to the Curriculum Engineers.

By the way, you might want to edit your post and link it to the M103 Course. And for next time, it will automatically link to the course if you create your post via the View Discussion button.

[Scott_78259 (Scott Dowd)]

Thank you for the quick response and for the guidance on the “Report an Issue” button and on linking the comment to the course. Will do so going forward.