I have replication setup as follows
Master A ----> Slave B ------> Slave C \-------> Slave D \------> Slave E - H
I use this setup because I need a local copy at the office server (that is slave C). I don't want to put extra strain on Master A because it's already receiving all of the inserts and extra load from the slaves connections.
So I setup multi level replication. Master A replicates to Slave B, which in turn is master to Slave C.
Replication from A -> B works perfectly. Replication from B -> C breaks constantly with "Duplicate key" errors. I have the relay log enabled in server B to enable replication from B to C.
Has anybody encountered this problem before?
Master / Slave B my.cnf is as follows:
# Replication setup log-bin=/var/log/mysql/mysql-bin server-id=2 sync_binlog=0 binlog_format=mixed log-slave-updates replicate-same-server-id = 0 expire_logs_days=15
Is there anything I'm doing wrong?