MySQL slave I/O thread not running
I have set up replication for MySQL server. I can connect from the slave machine to the master server using the replication user/password. I have got the slave SQL thread running, but the slave I/O thread is not running and the slave I/O status comes as empty when checked using 'show slave status'. What could be the problem?
How do I solve this? Restarting the slave does not help.
This was my bad: Instead of giving a 'replication slave' privilege to *.*, I was only giving it for my_db.*.
Answer
Instead of giving a 'replication slave' privilege to ., I was only giving it for my_db.*.
Replication slave is only a global privilege (i.e. per-user only), this means that a command such as
GRANT REPLICATION SLAVE on mydb.* TO 'someuser'@'%';
has no effect as you can't grant it per-database/column/table.
The command you need to run is:
GRANT REPLICATION SLAVE on *.* TO 'someuser'@'%';
Then do a START SLAVE. You might also find it useful to look in the mysql error log.
I'd suggest a good read of the replication setup documentation, as it explains all of this in detail.