What’s a Secondary or Slave?
A secondary is a node/member which applies operations from the current primary. This is done by tailing the replication oplog (local.oplog.rs). Replication from primary to secondary is asynchronous, however, the secondary will try to stay as close to current as possible (often this is just a few milliseconds on a LAN).
🔗Reference : stackoverflow.com
🔗Source: Azure Interview Questions and Answers
