truncate table 不能复制到从库

wubx — Fri, 06 Nov 2009 11:37:28 +0000

作者：吴炳锡　来源：http://www.mysqlsupport.cn/ 联系方式： wubingxi#gmail.com 转载请注明作/译者和出处，并且不能用于商业用途，违者必究。

bug说明：该BUG在是MySQL5.1.X中存在的一个问题。
重现方法：
利用 5.1.31-enterprise-gpl-pro-log (Or 5.1.31-sp1-enterprise) 搭建master/slave结构同步正常进行（确认同步进行）
注意参数：
事务隔级为： READ-COMMITTED
日值格式为： mixed

然后在主库建表：

create database wubx;
create table t1 (id int) engine=innodb;
insert into t1 values(1),(2),(3),(4),(5);
select * from t1;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
+------+

从库：

use wubx;
select * from t1 ;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
+------+

主库上：

use wubx;
mysql> truncate table t1;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from t1;
Empty set (0.01 sec)

从库：

use wubx;
select * from t1 ;
+------+
| id |
+------+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
+------+

解决办法：
先删除该表，然后创建该表。
如: truncate table wubx;改变为：

drop table wubx;
create table wubx( id int) engine=innodb;

另一种方式：
修改事务隔离级别为默认的。可以MySQL的版本升级到MySQL-5.1.37后的版本。

Relay log read failure的处理

wubx — Sun, 01 Nov 2009 08:35:47 +0000

作者：吴炳锡　来源：http://www.mysqlsupport.cn/ 联系方式：select unhex(’777562696E67786940676D61696C2E636F6D’); 载请注明作/译者和出处，并且不能用于商业用途，违者必究。
众所周知MySQL5.1的Replication是比较烂的。MySQL的每一个版本更新关于同步方面每次都是可以看到一大堆。但MySQL 5.1性能是比较突出的。所以经不住诱惑使用MySQL 5.1。所以也要经常遇到一些Bug。如：

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.10.118
                  Master_User: repl_wu
                  Master_Port: 3306
                Connect_Retry: 30
              Master_Log_File: mysql-bin.005121
          Read_Master_Log_Pos: 64337286
               Relay_Log_File: relay-bin.003995
                Relay_Log_Pos: 18446697137031827760
        Relay_Master_Log_File: mysql-bin.005121
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB:
          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: 4
              Relay_Log_Space: 64337901
              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.
1 row in set (0.00 sec)

从上面可以看到是中继日值或是Master上的日值出问题了。
首先如果是中继日值坏掉，那只需要找到同步的时间点，然后重新同步，这样就可以有新的中继日值了。如果Master上的日值坏了就麻烦了。
从经验来看，这是中继日值出问题了。处理方法：

需要找到同步的点。

日值为：Master_Log_File: mysql-bin.005121，Relay_Master_Log_File: mysql-bin.005121以Relay_Master_Log_File为准，Master_Log_File为参考。

日值执行时间点：

Exec_Master_Log_Pos: 4

那么现在就可以：

  
      mysql>stop slave;
 
    mysql>change master to Master_Log_File=’mysql-bin.005121’, Master_Log_Pos=4;
   
    mysql>start slave;
 
    mysql>show slave status\G;

进行确认。

建议：

在使用MySQL-5.1.36以下的版本的同学，请尽快升级到MySQL-5.1.40 & MySQL-5.1.37sp1

MySQL支持 » 同步中的Bug

truncate table 不能复制到从库

Relay log read failure的处理