这节引入了交易验证优化
但是我测试的时候jmeter并发线程数200的时候数据库直接锁超时了，所有配置和都老师一样，该怎么么解决那？

| 4053FF | LOCK WAIT | 2020-07-14 18:30:48 | 4053FF:0:341:3 | 2020-07-14 18:30:48 | 2 | 18 | update item_stock
set stock = stock-1
where item_id = 8 and stock>=1 | starting index read | 1 | 1 | 2 | 376 | 1 | 0 | 0 | REPEATABLE READ | 1 | 1 | NULL | 0 | 10000 |

The error may involve defaultParameterMap

The error occurred while setting parameters

SQL: update item_stock set stock = stock-? where item_id = ? and stock>=?

Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLTransactionRollbackException: Lock wait timeout exceeded; try restarting transaction

; ]; Lock wait timeout exceeded; try restarting transaction; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLTransactionRollbackException: Lock wait timeout exceeded; try restarting transaction]