3. Save all evidence before resetting the replication state. If we have no information or only sketchy information, it becomes difficult or impossible for us to track down the problem. The evidence you should collect is: 

•All binary log files from the source 

•All binary log files from the replica 

•The output of SHOW MASTER STATUS  from the source at the time you discovered the problem 

•The output of SHOW REPLICA | SLAVE STATUS  from the replica at the time you discovered the problem 

•Error logs from the source and the replica 

4. Use mysqlbinlog  to examine the binary logs. The following should be helpful to find the problem statement. log_file  and log_pos  are the Master_Log_File  and Read_Master_Log_Pos  values from SHOW REPLICA | SLAVE STATUS . 

shell> mysqlbinlog --start-position= log_pos log_file  | head 

After you have collected the evidence for the problem, try to isolate it as a separate test case first. Then enter the problem with as much information as possible into our bugs database using the instructions at Section 1.6, “How to Report Bugs or Problems” . 

