Reopening this because the documentation clearly states:
"examines the replicated heartbeat record from its immediate master or the specified --master-server-id..."
Thus, this leaves one to believe, that in the case of simple Master->Slave replication, pt-heartbeat should grab the server_id from SHOW SLAVE STATUS.
Only if there is doubt, like Master_Server_Id NOT FOUND from SELECT * FROM heartbeat WHERE server_id = XX should the script abort with the error about not being able to determine masters id
Reopening this because the documentation clearly states:
"examines the replicated heartbeat record from its immediate master or the specified --master- server- id..."
Thus, this leaves one to believe, that in the case of simple Master->Slave replication, pt-heartbeat should grab the server_id from SHOW SLAVE STATUS.
Only if there is doubt, like Master_Server_Id NOT FOUND from SELECT * FROM heartbeat WHERE server_id = XX should the script abort with the error about not being able to determine masters id