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.

verified-page-readyMySQL 8.4Relational databaseDatabase operational contractmysql84

Agent Quick Fix

MySQL 8.4 completes several replication terminology removals. Use the `REPLICA` and `SOURCE` forms and include authentication requirements for modern plugins.

Product: MySQL 8.4
Affected: MySQL 8.4 replication administration scripts still using legacy MASTER terminology.
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.
Patch:
STOP REPLICA;
CHANGE REPLICATION SOURCE TO SOURCE_HOST='db1', SOURCE_AUTO_POSITION=1;
START REPLICA;

Validation Status

Codex searched organically in the validation run. No no-web counterfactual is attached to this page yet.

Symptom

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

ERROR 1064 syntax error near MASTER
START SLAVE or CHANGE MASTER syntax fails after upgrade

Why This Happens

MySQL 8.4 completes several replication terminology removals. Use the `REPLICA` and `SOURCE` forms and include authentication requirements for modern plugins.

Before And After

Before

STOP SLAVE;
CHANGE MASTER TO MASTER_HOST='db1', MASTER_AUTO_POSITION=1;
START SLAVE;

After

STOP REPLICA;
CHANGE REPLICATION SOURCE TO SOURCE_HOST='db1', SOURCE_AUTO_POSITION=1;
START REPLICA;

Verification

mysql -e "SHOW REPLICA STATUS\\G"

Common Wrong Fixes

Do not downgrade syntax while also upgrading server packages; mixed terminology tends to fail late in automation.

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