Database operational contract

MySQL 8.4 CHANGE REPLICATION SOURCE TO SOURCE_HOST SOURCE_AUTO_POSITION MASTER_HOST deprecated removed

New syntax is used but legacy MASTER_HOST/MASTER_AUTO_POSITION options still cause errors.

MySQL 8.4Relational databaseDatabase operational contractmysql84

Agent Quick Fix

Repair against the current MySQL 8.4 contract, then keep the change narrow and source-backed.

Product: MySQL 8.4
Current-contract area: MASTER_* replication options removed
Likely root cause: New syntax is used but legacy MASTER_HOST/MASTER_AUTO_POSITION options still cause errors.
Repair direction: Verifier checks durability, restart, and operational safety rather than a one-shot query. Check operational state and security, not a compatibility switch that weakens the server.

Symptom

New syntax is used but legacy MASTER_HOST/MASTER_AUTO_POSITION options still cause errors.

Why This Happens

The local schema/query is valid, but upgrade path, restart behavior, replication syntax, or background operations changed in the server release.

Common Wrong Fixes

Changing local code without checking the current external contract.
Retrying the same install, build, or API call with no version/source change.
Applying a broad unsafe bypass when a narrow compatibility fix is available.

Codex Search Keywords

These are the search terms observed in a neutral Codex validation run for this failure shape.

MySQL 8.4 CHANGE REPLICATION SOURCE TO SOURCE_HOST SOURCE_AUTO_POSITION MASTER_HOST deprecated removed
site:dev.mysql.com/doc/refman/8.4 CHANGE REPLICATION SOURCE TO SOURCE_HOST SOURCE_AUTO_POSITION MASTER_HOST
dev.mysql.com MySQL 8.4 CHANGE REPLICATION SOURCE TO SOURCE_HOST
https://dev.mysql.com/doc/refman/8.4/en/change-replication-source-to.html
'MASTER_HOST' in https://dev.mysql.com/doc/refman/8.4/en/change-replication-source-to.html
https://dev.mysql.com/doc/refman/8.4/en/replication-compatibility.html
'CHANGE MASTER' in https://dev.mysql.com/doc/refman/8.4/en/mysql-nutshell.html