Hello,
I’ve been testing mongomirror on a 3.4.2 linux environment (3 node rs,not sharded) to do a data migration to Atlas. It worked initially, but took 4 days to move 400 Gb so we made some revisions to the destination config and are trying again, but can never get it started as there are oplog errors. I’ve resized the oplog across the cluster, but still cannot start mongomirror.
Here’s my errors:
2020-10-05T09:25:52.839-0500 Read timestamp from bookmark file: {1598788862 3}
2020-10-05T09:25:52.839-0500 Proceeding to tail oplog.
2020-10-05T09:25:52.841-0500 Current lag from source: 866h24m47s
2020-10-05T09:25:52.841-0500 NewOplogReader start time is greater than the final buffered timestamp
2020-10-05T09:25:52.841-0500 Tailing the oplog on the source cluster starting at timestamp: {1598788862 3}
2020-10-05T09:25:52.877-0500 Oplog tailer has shut down. Oplog applier will exit.
2020-10-05T09:25:52.877-0500 Waiting for new oplog entries to apply.
2020-10-05T09:25:52.877-0500 Fatal error while tailing the oplog on the source: Checkpoint not available in oplog! expected: {1598788862 3}; got: {1601235
193 1}
2020-10-05T09:25:52.877-0500 Timestamp file written to /var/lib/mongo/mongomirror-linux-x86_64-rhel70-0.9.1/bin/mongomirror.timestamp.
2020-10-05T09:25:52.877-0500 Failed: error while tailing the oplog on the source: Checkpoint not available in oplog! expected: {1598788862 3}; got: {16012
35193 1}
Is there some way to reset the oplog so that it does not cause this ? Is the mongomirror for one-time only use ?
Here’s the oplog info :
rs.printReplicationInfo()
configured oplog size: 77824MB
log length start to end: 677656secs (188.24hrs)
oplog first event time: Sun Sep 27 2020 14:33:13 GMT-0500 (CDT)
oplog last event time: Mon Oct 05 2020 10:47:29 GMT-0500 (CDT)
now: Mon Oct 05 2020 10:47:37 GMT-0500 (CDT)