MySQL中继日志已损坏，如何解决？尝试过但失败了

change master to master_log_file='<Relay_Master_Log_File>',
                 master_log_pos=<Exec_Master_Log_Pos>;

mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: the-master-host
                  Master_User: replication
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000021
          Read_Master_Log_Pos: 33639968
               Relay_Log_File: mysql-relay-bin.000271
                Relay_Log_Pos: 2031587
        Relay_Master_Log_File: mysql-bin.000020
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB: the_database
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      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 MySQL 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: 66395191
              Relay_Log_Space: 36559177
              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 MySQL 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.

mysql> stop slave;
mysql> reset slave;
mysql> change master to master_host='the-master-host', master_user='replication', master_password='the-password', master_log_file='mysql-bin.000020', master_log_pos=66395191;
mysql> start slave;

131122 15:17:29 [Note] Slave I/O thread: connected to master 'replication@the-master-host:3306',replication started in log 'mysql-bin.000020' at position 66395191
131122 15:17:29 [ERROR] Slave SQL: Error 'Duplicate entry '71373' for key 'PRIMARY'' on query. Default database: 'the_database'. Query: 'insert into ...  values ...', Error_code: 1062
131122 15:17:29 [Warning] Slave: Data truncated for column 'date' at row 1 Error_code: 1265
131122 15:17:29 [Warning] Slave: Duplicate entry '71373' for key 'PRIMARY' Error_code: 1062

Master_Log_File: mysql-bin.000026
Read_Master_Log_Pos: 2377104
Relay_Log_File: mysqld-relay-bin.000056
Relay_Log_Pos: 1097303
Relay_Master_Log_File: mysql-bin.000026
Exec_Master_Log_Pos: 1097157

mysqlbinlog mysql-bin.000026

mysqlbinlog mysqld-relay-bin.000056

ERROR: Error in Log_event::read_log_event(): 'read error', data_len: 336, event_type: 2
ERROR: Could not read entry at offset 1097414: Error in log format or read error.
DELIMITER ;
# End of log file
ROLLBACK /* added by mysqlbinlog */;
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
root@db:/var/lib/mysql#

mysql> stop slave;
Query OK, 0 rows affected (0.14 sec)

mysql> reset slave all;
Query OK, 0 rows affected (0.43 sec)

mysql>  CHANGE MASTER TO MASTER_HOST='master.host.com', MASTER_USER='masteruser', MASTER_PASSWORD='masterpass', MASTER_LOG_FILE='mysql-bin.000026', MASTER_LOG_POS=1097157;
Query OK, 0 rows affected (0.93 sec)

mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

Relay_Master_Log_File: mysql-bin.002045
Exec_Master_Log_Pos: 103641119

mysql> stop slave;
mysql> reset slave;
mysql> change master to master_host='the-master-host', master_user='replication', master_password='the-password', master_log_file='mysql-bin.000020', master_log_pos=66395191;
mysql> start slave;

INSERT INTO tablname (column,column) VALUES (value,value,...)

STOP SLAVE;
SET GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
START SLAVE;
SET @sleepnumber = SLEEP(3);
SHOW SLAVE STATUS\G