Maridb Replication Failure

MariaDB [(none)]> show all slaves status\G

               Connection_name:

               Slave_SQL_State:

                Slave_IO_State: Waiting for master to send event

                   Master_Host: 10.76.24.77

                   Master_User: gtid

                   Master_Port: 3306

                 Connect_Retry: 60

               Master_Log_File: db2-binary.571274

           Read_Master_Log_Pos: 18580673

                Relay_Log_File: db1-relay.152363

                 Relay_Log_Pos: 23439721

         Relay_Master_Log_File: db2-binary.570964

              Slave_IO_Running: Yes

             Slave_SQL_Running: No

               Replicate_Do_DB:

           Replicate_Ignore_DB:

            Replicate_Do_Table:

        Replicate_Ignore_Table: crmdb.quartz_scheduler_state,aaadb.quartz_scheduler_state,mysql.gtid_slave_pos,aaadb.systemconfigurations,pcrfdb.quartz_scheduler_state,activemq.activemq_lock,activemq.activemq_acks

       Replicate_Wild_Do_Table:

   Replicate_Wild_Ignore_Table:

                    Last_Errno: 1594

                    Last_Error: Relay log read failure: Could not parse relay log event entry. The possible reasons are: the master's binary log is corrupted (you can check this by running 'mysqlbinlog' on the binary log), the slave's relay log is corrupted (you can check this by running 'mysqlbinlog' on the relay log), a network problem, or a bug in the master's or slave's MariaDB code. If you want to check the master's binary log or slave's relay log, you will be able to know their names by issuing 'SHOW SLAVE STATUS' on this slave.

                  Skip_Counter: 0

           Exec_Master_Log_Pos: 90548127

               Relay_Log_Space: 65031291422

               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: NULL

Master_SSL_Verify_Server_Cert: No

                 Last_IO_Errno: 0

                 Last_IO_Error:

                Last_SQL_Errno: 1594

                Last_SQL_Error: Relay log read failure: Could not parse relay log event entry. The possible reasons are: the master's binary log is corrupted (you can check this by running 'mysqlbinlog' on the binary log), the slave's relay log is corrupted (you can check this by running 'mysqlbinlog' on the relay log), a network problem, or a bug in the master's or slave's MariaDB code. If you want to check the master's binary log or slave's relay log, you will be able to know their names by issuing 'SHOW SLAVE STATUS' on this slave.

   Replicate_Ignore_Server_Ids: 4, 5

              Master_Server_Id: 2

                Master_SSL_Crl:

            Master_SSL_Crlpath:

                    Using_Gtid: No

                   Gtid_IO_Pos:

       Replicate_Do_Domain_Ids:

   Replicate_Ignore_Domain_Ids:

                 Parallel_Mode: optimistic

                     SQL_Delay: 0

           SQL_Remaining_Delay: NULL

       Slave_SQL_Running_State:

              Slave_DDL_Groups: 5

Slave_Non_Transactional_Groups: 0

    Slave_Transactional_Groups: 456599065

          Replicate_Rewrite_DB:

          Retried_transactions: 230

            Max_relay_log_size: 67108864

          Executed_log_entries: 2285247538

     Slave_received_heartbeats: 0

        Slave_heartbeat_period: 30.000

                Gtid_Slave_Pos: 0-2-72183383362,1-1-1095522539,2-2-200638781,4-4-1346164691,5-5-242105

mmm logs

2026/01/26 03:05:00 ERROR Check 'rep_threads' on 'db1' has failed for 10 seconds! Message: ERROR: Replication is broken

2026/01/26 03:05:02 FATAL State of host 'db1' changed from ONLINE to REPLICATION_FAIL

2026/01/26 03:05:02  INFO Removing all roles from host 'db1':

2026/01/26 12:18:31  INFO Check 'rep_threads' on 'db1' is ok!

2026/01/26 12:18:32 FATAL State of host 'db1' changed from REPLICATION_FAIL to ONLINE

2026/01/26 12:18:39 ERROR Check 'rep_backlog' on 'db1' has failed for 10 seconds! Message: ERROR: Backlog is too big

2026/01/26 12:18:41 FATAL State of host 'db1' changed from ONLINE to REPLICATION_DELAY

2026/01/26 12:18:41  INFO Removing all roles from host 'db1':

2026/01/26 12:19:44 ERROR Check 'rep_backlog' on 'db3' has failed for 10 seconds! Message: ERROR: Backlog is too big

2026/01/26 12:19:59  INFO Check 'rep_backlog' on 'db3' is ok!

2026/01/26 12:20:14 ERROR Check 'rep_backlog' on 'db3' has failed for 10 seconds! Message: ERROR: Backlog is too big

2026/01/26 12:21:34  INFO Check 'rep_backlog' on 'db3' is ok!

2026/01/26 12:22:19 ERROR Check 'rep_backlog' on 'db3' has failed for 10 seconds! Message: ERROR: Backlog is too big

2026/01/26 12:24:10  INFO Check 'rep_backlog' on 'db3' is ok!

2026/01/26 12:24:25 ERROR Check 'rep_backlog' on 'db3' has failed for 10 seconds! Message: ERROR: Backlog is too big

2026/01/26 12:24:40  INFO Check 'rep_backlog' on 'db3' is ok!

2026/01/26 12:24:55 ERROR Check 'rep_backlog' on 'db3' has failed for 10 seconds! Message: ERROR: Backlog is too big

2026/01/26 12:29:42  INFO Check 'rep_backlog' on 'db3' is ok!

2026/01/26 12:29:57 ERROR Check 'rep_backlog' on 'db3' has failed for 10 seconds! Message: ERROR: Backlog is too big.