In MySQL replication, what does the replica's I/O thread do?
- A Applies events to the replica's tables
- B Reads events from the source's binary log into the local relay log
- C Writes to the source's binary log
- D Performs backups
Answer
Reads events from the source's binary log into the local relay log
The I/O thread fetches events into the relay log and a separate applier (SQL) thread replays them, which is why lag can occur in either stage.





