mysqldump 备份需要锁表

show engine innodb statusG

------------
TRANSACTIONS
------------
Trx id counter 117509
Purge done for trx's n:o < 112086 undo n:o < 0 state: running but idle
History list length 224
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 2, OS thread handle 0x7f33aab99700, query id 13 localhost root init
show engine innodb status


开始备份:
------------
TRANSACTIONS
------------
Trx id counter 119049
Purge done for trx's n:o < 118074 undo n:o < 0 state: running but idle
History list length 300
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 2, OS thread handle 0x7fb128107700, query id 47 localhost root init
show engine innodb status
---TRANSACTION 119048, ACTIVE 18 sec fetching rows
mysql tables in use 1, locked 1
1 lock struct(s), heap size 360, 0 row lock(s)
MySQL thread id 4, OS thread handle 0x7fb1280c6700, query id 43 localhost mysql Sending data
SELECT /*!40001 SQL_NO_CACHE */ * FROM `t3`
Trx read view will not see trx with id >= 119049, sees < 119049



------------
TRANSACTIONS
------------
Trx id counter 119051
Purge done for trx's n:o < 118074 undo n:o < 0 state: running but idle
History list length 300
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 6, OS thread handle 0x7fb128085700, query id 128 localhost root init
show engine innodb status

---TRANSACTION 119050, ACTIVE 43 sec
mysql tables in use 1, locked 1
1 lock struct(s), heap size 360, 0 row lock(s)
MySQL thread id 5, OS thread handle 0x7fb1280c6700, query id 117 localhost mysql Sending data
SELECT /*!40001 SQL_NO_CACHE */ * FROM `t3`
Trx read view will not see trx with id >= 119051, sees < 119049

---TRANSACTION 119049, ACTIVE 107 sec
mysql tables in use 1, locked 1
MySQL thread id 2, OS thread handle 0x7fb128107700, query id 118 localhost root Waiting for table level lock
insert into t3 values(25255,'a','a','20110101')
Trx read view will not see trx with id >= 119050, sees < 119050



mysql> insert into t3 values(9999999999,'a','a','20110101'); --HANG

[mysql@master data]$ mysqldump test t3>t3.sql备份需要锁表