Error from master error log while doing a replication to slave
Try to raise the slave_net_timeout. Prior to version 5.7.7, it was set to 3600, now to 60. Therefore, if you have any trouble on the network, the slave will think it has lost connection the server but when a Slave tries to [re]connect, it creates a dump thread on Master. Before Master creates a dump thread, it checks if there is already a dump thread running for that Slave (using the UUID value). If yes, it considers that old dump thread as "Zombie" dump thread and kills it. Creates a new one and prints this "Note" in the error log file. (This is cited from the official MySQL site )

Practically speaking: Enter MySQL on the slave machine and

mysql&gt; set global slave_net_timeout=3600;


Restart your MySQL server and it should solve the problem.

Once this is OK, you can add this parameter in the configuration file my.conf to make the changes definitive.