Mysql 如何预估后台回滚事务的时长
没有停机时间和潜在的数据丢失，就不能简单地停止回滚。
建议等待回滚自行完成。要估计回滚需要多长时间，请登录mysql并执行几次以监控其进度:
mysql> select now(),trx_state,trx_operation_state,trx_weight,trx_rows_locked,trx_rows_modified from information_schema.innodb_trx where trx_state='ROLLING BACK';do sleep(10);
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
| now() | trx_state | trx_operation_state | trx_weight | trx_rows_locked | trx_rows_modified |
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
| 2017-11-15 15:20:19 | ROLLING BACK | rollback | 17028388 | 64342541 | 16672912 |
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
1 row in set (0.01 sec)
Query OK, 0 rows affected (10.00 sec)
mysql> select now(),trx_state,trx_operation_state,trx_weight,trx_rows_locked,trx_rows_modified from information_schema.innodb_trx where trx_state='ROLLING BACK';do sleep(10);
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
| now() | trx_state | trx_operation_state | trx_weight | trx_rows_locked | trx_rows_modified |
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
| 2017-11-15 15:20:29 | ROLLING BACK | rollback | 16245596 | 64342541 | 15906465 |
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
1 row in set (0.01 sec)
Query OK, 0 rows affected (10.00 sec)
mysql> select now(),trx_state,trx_operation_state,trx_weight,trx_rows_locked,trx_rows_modified from information_schema.innodb_trx where trx_state='ROLLING BACK';do sleep(10);
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
| now() | trx_state | trx_operation_state | trx_weight | trx_rows_locked | trx_rows_modified |
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
| 2017-11-15 15:20:39 | ROLLING BACK | rollback | 15463244 | 64342541 | 15140438 |
+---------------------+--------------+---------------------+------------+-----------------+-------------------+
1 row in set (0.00 sec)
Query OK, 0 rows affected (10.00 sec)
