Hello, we have upgraded our MySQL Master/Slave server vom 10.1.24 to 10.1.48 on 25.01. Backups worked as usual, but since friday (29.01.) our backups do not work anymore. I have seen that entering a 'stop slave;' on mysql cli hangs forever, while in the background (on a second console, I see the replication going on, but the gtid is far away from the master. According to MaxScale, on the slave it is '0-1-8696229561 and on the master '0-1-8705275411' and not moving forward on the slave. Slave 'show slave status': MariaDB [(none)]> show slave status\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 172.16.1.1 Master_User: replication_user Master_Port: 3306 Connect_Retry: 10 Master_Log_File: mysql-bin.005595 Read_Master_Log_Pos: 581894706 Relay_Log_File: relay-bin.000002 Relay_Log_Pos: 693 Relay_Master_Log_File: mysql-bin.005587 Slave_IO_Running: Yes Slave_SQL_Running: Yes Replicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0 Last_Error: Skip_Counter: 0 Exec_Master_Log_Pos: 967647646 Relay_Log_Space: 8205026277 Until_Condition: None Until_Log_File: Until_Log_Pos: 0 Master_SSL_Allowed: No Master_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: 0 Master_SSL_Verify_Server_Cert: No Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 0 Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 1 Master_SSL_Crl: Master_SSL_Crlpath: Using_Gtid: Slave_Pos Gtid_IO_Pos: 0-1-8705427292 Replicate_Do_Domain_Ids: Replicate_Ignore_Domain_Ids: Parallel_Mode: optimistic 1 row in set (0.00 sec) Master status is this: MariaDB [(none)]> show master status\G *************************** 1. row *************************** File: mysql-bin.005595 Position: 581594839 Binlog_Do_DB: Binlog_Ignore_DB: 1 row in set (0.01 sec) If I try to stop the server it hangs also. Waited half an hour after I saw the backups hanging on the 'stop slave' command, then killed the server with kill -9. It restarted without complaining, but the hang is still occuring when doing a 'stop slave'. Can anybody help me diagnosing and possibly resolving this issue? Server is a baremetal with battery backed raid10. OS is Centos 7 all updated. Thanks, Thomas