EC
1200
MySQLERRORNotableReplicationHIGH confidence

Server is not configured as a slave

Production Risk

Low — configuration issue, no data affected.

What this means

ER_BAD_SLAVE (1200, SQLSTATE HY000) is raised when replication commands are run on a server that has not been configured as a replica. The master host and connection parameters have not been set.

Why it happens
  1. 1Running START SLAVE or SHOW SLAVE STATUS on a server without CHANGE MASTER TO having been executed
  2. 2Replication configuration lost after server restart (missing my.cnf settings)
How to reproduce
trigger — this will error
trigger — this will error
-- On a fresh server with no replication config
START SLAVE;

expected output

ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO

Fix

Configure replication with CHANGE MASTER TO

Configure replication with CHANGE MASTER TO
CHANGE MASTER TO
  MASTER_HOST = 'primary-host',
  MASTER_USER = 'repl_user',
  MASTER_PASSWORD = 'password',
  MASTER_LOG_FILE = 'mysql-bin.000001',
  MASTER_LOG_POS = 4;
START SLAVE;

Why this works

Provides the replica with the necessary connection details to connect to the primary.

Version notes

Sources
Official documentation ↗

MySQL 8.0 — 1200 ER_BAD_SLAVE

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