A systems administrator has set up cross-region database replication to enhance disaster recovery capabilities. After a recent deployment, they observe that the replication lag has increased unexpectedly, even though there have been no changes in network latency or in the volume of data being processed. Assuming that the replication software and configuration have been verified as correct, which of the following should the administrator investigate FIRST to address the increased replication lag?
Re-examine the replication user credentials to make sure they have the necessary permissions.
Verify that the database engine versions are compatible in both regions.
Review the recent deployment logs for any changes that could potentially impact database performance or replication.
Check if there have been unexpected changes to the IP space that might be impacting replication traffic.