To repeat the title: MySQL replication working fine, but mytop still shows a thread "Waiting for master to send event". It has been like this for a few days, and is now at 280000 seconds. But replication is just fine.
I can see another thread which is doing the replication work, right now it is sitting on "Slave has read all relay log; waiting for the slave I/O thread to update it" but it has been running queries, and I can verify that the slave is up to date just by viewing the data.
Can I kill this process?
I recently had to re-set up replication, and that involved creating a new replication user, so I'm not sure if this is what has caused this "ghost replication process".