And one more thing if I might suggest.. I also documented our observation on oplog-replay (during reconciliation tests to validate snaps + oplogs consistency in our recovery strategy) the current issue with how PBM ensures consistency / precision in regards to timestamps.
From our point of view it would be not just “nice to have” but inherently logical, to treat oplog-replay surgically. By this I mean that –start / –end should not rely on seconds and truncate ‘increment’ positions. In our cases with oplog-heavy instances, there might be thousands of operations in the single exact second (epoch timestamp). Hence we observed the inconsistent result due to not being able to tell the oplog-replay at which exact operation-position to stop, while processing oplog chunks.
Oracle ensures that level of consistency by using it’s own sequencing mechanism for all operations. Unfortunately mongo operates in unix epoch + increments..