Database operational contract

MySQL 8.4 START SLAVE removed syntax error START REPLICA official docs

Replication automation fails with SQL syntax error on the new server.

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: START SLAVE removed in MySQL 8.4
Likely root cause: Replication automation fails with SQL syntax error on the new server.
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

Replication automation fails with SQL syntax error on the new server.

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 START SLAVE removed syntax error START REPLICA official docs
site:dev.mysql.com/doc/refman/8.4 START SLAVE START REPLICA
MySQL 8.4 START REPLICA manual
https://dev.mysql.com/doc/refman/8.4/en/start-replica.html
https://dev.mysql.com/doc/refman/8.0/en/start-slave.html
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/
https://dev.mysql.com/doc/relnotes/mysql/8.4/en/news-8-4-0.html

Source Trail