My slave just sits there...

[Robert Gunther]

I've got a setup with three servers


Server A <-> Server B

A & B are both masters, transactions are replicated in realtime and it works well.

Server B -> Server C

Server C is a slave off Server B (server B has log_slave_updates enabled, so Server C gets all).


So that is the setup in a nutshell. If I do show slave status on Server B I can see that the read_master_log_pos changes continuously, every 1 or 2 seconds that value changes which leads me to belive replication is happening - it is reading data in realtime.

If I do show slave status on Server C, the value of Read_Master_Log_Pos does not change often. It might change maybe every 20 minutes or more (I do not know exactly how often).

The Slave_IO_Running & Slave_SQL_Running are Yes on all servers.

Beyond that I have checked the servername.err file in the MySQL data folder. The log shows information about Slave SQL thread initialized, starting and general status information. like server starting, shutdown etc. There is nothing in the logs to indicate any type of error or lag condition.

If I check the process list on Server C, it will show a state of 'Waiting for master to send event' and 'Slave has read all relay log; waiting for the slave I/O thread to update it'

Any clues how to find out what is wrong with Server C? It seems to think there is nothing new to replicate. In reality I have seen it lag by hours or days behind the masters. He is like a lazy employee, only working when he wants to!


Robert G.