背景：有3台服务器，做了1主2从
主：192.168.0.2
从：192.168.0.9/192.168.0.6
先从同好0.6的数据，再启动0.9，同步数据时候，Seconds_Behind_Master的值一直保持某个数值，日志里面产生了几万个localhost-relay-bin.*的文件，日志报如下错误：
121101 11:38:52 [Note] Slave: received end packet from server, apparent master shutdown:
121101 11:38:52 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.000002' at postion 188278072
121101 11:38:52 [Note] Slave: received end packet from server, apparent master shutdown:
121101 11:38:52 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.000002' at postion 188279159
121101 11:38:52 [Note] Slave: received end packet from server, apparent master shutdown:
121101 11:38:52 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.000002' at postion 188279159
121101 11:38:52 [Note] Slave: received end packet from server, apparent master shutdown:
121101 11:38:52 [Note] Slave I/O thread: Failed reading log event, reconnecting to retry, log 'mysql-bin.000002' at postion 188280253
从网上搜索，是说由于server-id相同而造成的。因为搭建环境之后，/etc/my.cnf是直接从0.6上面复制过来的
解决方法：
修改0.9上面的server-id=3，停数据库，把datadir里面的日志全部删除，重启数据库，重新同步，OK
