Bug #22669 "start slave" fails to return error when master and slave have same ID
Submitted: 25 Sep 2006 15:26 Modified: 26 Sep 2006 18:31
Reporter: Jim Dowling Email Updates:
Status: Not a Bug Impact on me:
None 
Category:MySQL Server: Replication Severity:S3 (Non-critical)
Version:5.1.11 OS:Linux (Linux)
Assigned to: CPU Architecture:Any

[25 Sep 2006 15:26] Jim Dowling
Description:
When a master and slave have the same "server-id", and a mysql-client connected to the slave issues:
>start slave
No error is given.
However, 
>show slave status
tells us the io thread is not running, and the mysqld error logs tell us the error that the master and slave have the same id

How to repeat:
configure a master and slave to have the same server-id, and issue a start slave command on a mysql-client connected to the slave.
No error or warning is returned.
[26 Sep 2006 18:31] Valeriy Kravchuk
Thank you for a problem report. Sorry, but this is a documented behaviour. Read http://dev.mysql.com/doc/refman/5.1/en/start-slave.html. START SLAVE may not really start replication for many reasons, including those you described. You must check the slave's error log for error messages generated by the slave threads, or check that they are running satisfactorily with SHOW SLAVE STATUS.