mysql创建临时表+事务会导致死锁
mysql创建临时表+事务会导致死锁
提问于 2014-05-20 19:37:26
我有一个复杂的查询，它创建一个可以运行5秒或更长时间的临时表。当同时在类似的表上运行另一个事务时，这似乎会导致死锁。我不能在当地复制，但在生产中，我可以让它每隔几天发生一次。(我记录了mysql错误)
查询相当复杂(如页面底部所示)；但是您不需要理解逻辑；只是它从一堆表和联接中选择，运行起来可能需要一段时间。
我还有一个事务可以插入到许多相同的表中。我偶尔会收到mysql错误，1213: Deadlock found when trying to get lock; try restarting transaction.。
下面是事务的伪代码
START TRANSACTION
INSERT INTO phppos_sales
INSERT MANY RECORDS INTO phppos_sales_items
INSERT MANY RECORDS INTO phppos_sales_items_taxes
INSERT MANY RECORDS INTO phppos_sales_payments
END TRANSACTION我该如何解决这个僵局？我试图更改隔离水平以读取未提交的数据，但是mysql设置不允许这样做；我需要在没有服务器控制的各种环境中使其工作。
更改隔离级别时出错：
无法执行语句:不可能写入二进制日志，因为BINLOG_FORMAT =语句，而且至少有一个表使用了限制在基于行的日志记录的存储引擎。当事务隔离级别读取、提交或读取未提交时，InnoDB仅限于行日志记录。
INNODB引擎状态：
mysql> SHOW ENGINE INNODB STATUS;
| Type | Name | Status |
| InnoDB | |
=====================================
140520 12:00:17 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 15 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 1766819 1_second, 1766816 sleeps, 167043 10_second, 100947 background, 100945 flush
srv_master_thread log flush and writes: 1776023
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 236559, signal count 288374
Mutex spin waits 546890, rounds 1796579, OS waits 33216
RW-shared spins 205374, rounds 5519210, OS waits 176937
RW-excl spins 5661, rounds 841678, OS waits 23933
Spin rounds per wait: 3.29 mutex, 26.87 RW-shared, 148.68 RW-excl
------------------------
LATEST FOREIGN KEY ERROR
------------------------
140520 11:27:44 Transaction:
TRANSACTION 86D125F, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
15 lock struct(s), heap size 3112, 6 row lock(s), undo log entries 2
MySQL thread id 1910245, OS thread handle 0x7fbf0042e700, query id 56114114 php-pos-web 10.181.16.33 phppoint update
INSERT INTO `phppos_sales_items_taxes` (`sale_id`, `item_id`, `line`, `name`, `percent`, `cumulative`) VALUES (11763, 1115, 3, 'PST', '8.000', '0')
Foreign key constraint fails for table `phppoint_fatpanda`.`phppos_sales_items_taxes`:
,
CONSTRAINT `phppos_sales_items_taxes_ibfk_1` FOREIGN KEY (`sale_id`) REFERENCES `phppos_sales_items` (`sale_id`)
Trying to add in child table, in index `PRIMARY` tuple:
DATA TUPLE: 8 fields;
0: len 4; hex 80002df3; asc - ;;
1: len 4; hex 8000045b; asc [;;
2: len 4; hex 80000003; asc ;;
3: len 3; hex 505354; asc PST;;
4: len 8; hex 8000000000080000; asc ;;
5: len 6; hex 0000086d125f; asc m _;;
6: len 7; hex 00000000000000; asc ;;
7: len 4; hex 80000000; asc ;;
But in parent table `phppoint_fatpanda`.`phppos_sales_items`, in index `PRIMARY`,
the closest match we can find is record:
PHYSICAL RECORD: n_fields 11; compact format; info bits 0
0: len 4; hex 80002df1; asc - ;;
1: len 4; hex 8000049a; asc ;;
2: len 4; hex 80000001; asc ;;
3: len 6; hex 0000086cfd29; asc l );;
4: len 7; hex f400000216012c; asc ,;;
5: len 0; hex ; asc ;;
6: len 0; hex ; asc ;;
7: len 11; hex 8000000000010000000000; asc ;;
8: len 11; hex 8000000000100000000000; asc ;;
9: len 11; hex 80000000002d0000000000; asc - ;;
10: len 4; hex 80000000; asc ;;
------------------------
LATEST DETECTED DEADLOCK
------------------------
140520 11:27:44
*** (1) TRANSACTION:
TRANSACTION 86D11A3, ACTIVE 2 sec fetching rows
mysql tables in use 9, locked 9
LOCK WAIT 364 lock struct(s), heap size 47544, 80177 row lock(s)
MySQL thread id 1910243, OS thread handle 0x7fbeb2090700, query id 56113840 10.181.26.42 phppoint Copying to tmp table
CREATE TEMPORARY TABLE phppos_sales_items_temp
(SELECT phppos_sales.deleted as deleted,phppos_sales.deleted_by as deleted_by, sale_time, date(sale_time) as sale_date, phppos_sales_items.sale_id, comment,payment_type, customer_id, employee_id,
phppos_items.item_id, NULL as item_kit_id, supplier_id, quantity_purchased, item_cost_price, item_unit_price, category,
discount_percent, (item_unit_price*quantity_purchased-item_unit_price*quantity_purchased*discount_percent/100) as subtotal,
phppos_sales_items.line as line, serialnumber, phppos_sales_items.description as description,
(item_unit_price*quantity_purchased-item_unit_price*quantity_purchased*discount_percent/100)+(item_unit_price*quantity_purchased-item_unit_price*quantity_purchased*discount_percent/100)*(SUM(CASE WHEN cumulative != 1 THEN percent ELSE 0 END)/100)
+(((item_unit_price*quantity_purchased-item_unit_price*quanti
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 454941 page no 114 n bits 408 index `location_id` of table `phppoint_fatpanda`.`phppos_sales` trx id 86D11A3 lock mode S waiting
Record lock, heap no 335 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
0: len 4; hex 80000001; asc ;;
1: len 4; hex 80002df3; asc - ;;
*** (2) TRANSACTION:
TRANSACTION 86D125D, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
23 lock struct(s), heap size 3112, 12 row lock(s), undo log entries 10
MySQL thread id 1910245, OS thread handle 0x7fbf0042e700, query id 56114091 php-pos-web 10.181.16.33 phppoint update
INSERT INTO `phppos_sales_items_taxes` (`sale_id`, `item_id`, `line`, `name`, `percent`, `cumulative`) VALUES (11763, 1178, 2, 'GST', '5.000', '0')
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 454941 page no 114 n bits 408 index `location_id` of table `phppoint_fatpanda`.`phppos_sales` trx id 86D125D lock_mode X locks rec but not gap
Record lock, heap no 335 PHYSICAL RECORD: n_fields 2; compact format; info bits 0
0: len 4; hex 80000001; asc ;;
1: len 4; hex 80002df3; asc - ;;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 454945 page no 386 n bits 288 index `PRIMARY` of table `phppoint_fatpanda`.`phppos_sales_items_taxes` trx id 86D125D lock_mode X insert intention waiting
Record lock, heap no 1 PHYSICAL RECORD: n_fields 1; compact format; info bits 0
0: len 8; hex 73757072656d756d; asc supremum;;
*** WE ROLL BACK TRANSACTION (2)
------------
TRANSACTIONS
------------
Trx id counter 86E47F7
Purge done for trx's n:o < 86E45C0 undo n:o < 0
History list length 1418
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 86E47F6, not started
MySQL thread id 1913171, OS thread handle 0x7fbeb2090700, query id 56205829 10.181.26.42 phppoint
---TRANSACTION 0, not started
MySQL thread id 1913095, OS thread handle 0x7fbf005b4700, query id 56205830 localhost root
SHOW ENGINE INNODB STATUS
--------
FILE I/O
--------
I/O thread 0 state: waiting for completed aio requests (insert buffer thread)
I/O thread 1 state: waiting for completed aio requests (log thread)
I/O thread 2 state: waiting for completed aio requests (read thread)
I/O thread 3 state: waiting for completed aio requests (read thread)
I/O thread 4 state: waiting for completed aio requests (read thread)
I/O thread 5 state: waiting for completed aio requests (read thread)
I/O thread 6 state: waiting for completed aio requests (write thread)
I/O thread 7 state: waiting for completed aio requests (write thread)
I/O thread 8 state: waiting for completed aio requests (write thread)
I/O thread 9 state: waiting for completed aio requests (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
3599456 OS file reads, 9300371 OS file writes, 3988632 OS fsyncs
0.27 reads/s, 16384 avg bytes/read, 13.07 writes/s, 7.27 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 84, seg size 86, 55915 merges
merged operations:
insert 68506, delete mark 4761, delete 38
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 2212699, node heap has 751 buffer(s)
5050.86 hash searches/s, 624.09 non-hash searches/s
---
LOG
---
Log sequence number 184365806376
Log flushed up to 184365806376
Last checkpoint at 184365791715
0 pending log writes, 0 pending chkp writes
2149282 log i/o's done, 3.47 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 1098907648; in additional pool allocated 0
Dictionary memory allocated 62951505
Buffer pool size 65536
Free buffers 1
Database pages 64784
Old database pages 23894
Modified db pages 88
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 4073451, not young 0
0.07 youngs/s, 0.00 non-youngs/s
Pages read 3592230, created 1542046, written 6130789
0.27 reads/s, 18.00 creates/s, 6.40 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 64784, unzip_LRU len: 0
I/O sum[382]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
1 read views open inside InnoDB
Main thread process no. 15866, id 140457065543424, state: sleeping
Number of rows inserted 77431960, updated 1673031, deleted 160450, read 4825684197
1103.93 inserts/s, 2.53 updates/s, 0.00 deletes/s, 7772.15 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
|
+-------查询这是死锁的一部分：(以及上面的事务)
CREATE temporary TABLE phppos_sales_items_temp
(SELECT
phppos_sales.deleted AS deleted,
phppos_sales.deleted_by AS deleted_by,
sale_time,
Date(sale_time) AS sale_date,
phppos_sales_items.sale_id,
comment,
payment_type,
customer_id,
employee_id,
phppos_items.item_id,
NULL AS item_kit_id,
supplier_id,
quantity_purchased,
item_cost_price,
item_unit_price,
category,
discount_percent,
( item_unit_price * quantity_purchased -
item_unit_price * quantity_purchased *
discount_percent / 100 ) AS subtotal,
phppos_sales_items.line AS line,
serialnumber,
phppos_sales_items.description AS description,
( item_unit_price * quantity_purchased -
item_unit_price * quantity_purchased *
discount_percent / 100 ) + (
item_unit_price * quantity_purchased -
item_unit_price * quantity_purchased *
discount_percent
/ 100 ) * ( Sum(CASE
WHEN cumulative != 1 THEN percent
ELSE 0
end) / 100 ) + ( ( (
item_unit_price * quantity_purchased
-
item_unit_price * quantity_purchased
*
discount_percent / 100 ) * (
Sum(CASE
WHEN cumulative != 1 THEN
percent
ELSE 0
end) / 100 ) + (
item_unit_price * quantity_purchased
-
item_unit_price *
quantity_purchased
*
discount_percent /
100
)
)
* ( Sum(CASE
WHEN
cumulative = 1 THEN percent
ELSE
0
end)
)
/ 100 )
AS total,
( item_unit_price * quantity_purchased -
item_unit_price * quantity_purchased *
discount_percent / 100 ) * (
Sum(CASE
WHEN cumulative != 1 THEN percent
ELSE 0
end) / 100 ) + ( ( ( item_unit_price * quantity_purchased -
item_unit_price * quantity_purchased *
discount_percent / 100 ) * ( Sum(
CASE
WHEN cumulative != 1
THEN
percent
ELSE 0
end) / 100 ) + (
item_unit_price * quantity_purchased
-
item_unit_price * quantity_purchased
*
discount_percent / 100 ) ) * ( Sum(
CASE
WHEN cumulative = 1 THEN percent
ELSE 0
end) ) / 100 ) AS tax,
( item_unit_price * quantity_purchased -
item_unit_price * quantity_purchased *
discount_percent / 100 ) - (
item_cost_price * quantity_purchased ) AS profit
FROM phppos_sales_items
INNER JOIN phppos_sales
ON phppos_sales_items.sale_id = phppos_sales.sale_id
INNER JOIN phppos_items
ON phppos_sales_items.item_id = phppos_items.item_id
LEFT OUTER JOIN phppos_suppliers
ON phppos_items.supplier_id = phppos_suppliers.person_id
LEFT OUTER JOIN phppos_sales_items_taxes
ON phppos_sales_items.sale_id =
phppos_sales_items_taxes.sale_id
AND phppos_sales_items.item_id =
phppos_sales_items_taxes.item_id
AND phppos_sales_items.line =
phppos_sales_items_taxes.line
WHERE sale_time BETWEEN "2014-04-01 00:00:00" AND "2014-04-30 23:59:59"
AND phppos_sales.location_id = '1'
AND phppos_sales.store_account_payment = 0
GROUP BY sale_id,
item_id,
line)
UNION ALL
(SELECT phppos_sales.deleted
AS
deleted
,
phppos_sales.deleted_by
AS deleted_by,
sale_time,
Date(sale_time)
AS
sale_date,
phppos_sales_item_kits.sale_id,
comment,
payment_type,
customer_id,
employee_id,
NULL
AS
item_id,
phppos_item_kits.item_kit_id,
''
AS
supplier_id,
quantity_purchased,
item_kit_cost_price,
item_kit_unit_price,
category,
discount_percent,
( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased * discount_percent / 100 )
AS
subtotal,
phppos_sales_item_kits.line
AS
line,
''
AS
serialnumber,
phppos_sales_item_kits.description
AS
description,
( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased * discount_percent / 100 )
+
( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased * discount_percent / 100 ) *
( Sum( CASE WHEN cumulative != 1 THEN percent ELSE 0 end) / 100 )
+ ( ( ( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased * discount_percent / 100 ) *
( Sum(CASE
WHEN cumulative != 1 THEN percent
ELSE 0
end)
/
100 ) + ( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased *
discount_percent / 100 ) ) * (
Sum(
CASE
WHEN cumulative = 1 THEN percent
ELSE 0
end) ) / 100 ) AS total,
( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased * discount_percent / 100 ) * ( Sum(
CASE
WHEN cumulative != 1 THEN percent
ELSE 0
end) / 100 ) + ( ( ( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased
*
discount_percent
/ 100 ) * ( Sum(
CASE
WHEN cumulative != 1 THEN percent
ELSE 0
end) / 100 ) + (
item_kit_unit_price * quantity_purchased
-
item_kit_unit_price *
quantity_purchased
* discount_percent / 100 ) ) *
(
Sum(CASE
WHEN cumulative = 1 THEN percent
ELSE 0
end) ) / 100 ) AS tax,
( item_kit_unit_price * quantity_purchased -
item_kit_unit_price * quantity_purchased * discount_percent / 100 ) - (
item_kit_cost_price * quantity_purchased ) AS profit
FROM phppos_sales_item_kits
INNER JOIN phppos_sales
ON phppos_sales_item_kits.sale_id = phppos_sales.sale_id
INNER JOIN phppos_item_kits
ON phppos_sales_item_kits.item_kit_id =
phppos_item_kits.item_kit_id
LEFT OUTER JOIN phppos_sales_item_kits_taxes
ON phppos_sales_item_kits.sale_id =
phppos_sales_item_kits_taxes.sale_id
AND phppos_sales_item_kits.item_kit_id =
phppos_sales_item_kits_taxes.item_kit_id
AND phppos_sales_item_kits.line =
phppos_sales_item_kits_taxes.line
WHERE sale_time BETWEEN "2014-04-01 00:00:00" AND "2014-04-30 23:59:59"
AND phppos_sales.location_id = '1'
AND phppos_sales.store_account_payment = 0
GROUP BY sale_id,
item_kit_id,
line)
ORDER BY sale_id,
line; 回答 1
Stack Overflow用户
回答已采纳
发布于 2014-05-22 21:00:22
根本原因
当将SELECT与写入语句(如INSERT INTO...或CREATE TABLE AS... )组合时，MySQL必须对SELECT中涉及的表建立共享锁。
您有另一个并发事务(2)，它在表phppos_sales上持有独占锁，因此事务(1)无法获得它的S锁，事务(1)等待。
然后，事务(2)请求tale phppos_sales_items_taxes上的X锁。但是，事务(1)已经在队列中以获得该表上的S锁，而事务(2)必须在队列中等待。
因此，事务(2)等待事务(1)，而事务(1)等待事务(2)。这是典型的僵局。
这种情况每隔几天才发生一次，因为这取决于事务(2)在事务(1)启动其phppos_sales之前获得它的第一个SELECT锁。然后，事务(2)在事务(1)将其S锁请求排队之后，尝试获取其在phppos_sales_items_taxes上的第二锁。
换句话说，这是一种种族条件，而且很难复制。
补救措施
如果事务(2)请求它所需的所有表上的锁作为原子操作，那么事务(1)将无法在锁请求之间插入。
您可以通过显式使用LOCK TABLES来实现这一点。
START TRANSACTION
LOCK TABLES phppos_sales WRITE, phppos_sales_items WRITE,
phppos_sales_items_taxes WRITE, ...other table(s)...
INSERT INTO phppos_sales
INSERT MANY RECORDS INTO phppos_sales_items
INSERT MANY RECORDS INTO phppos_sales_items_taxes
INSERT MANY RECORDS INTO phppos_sales_payments
UNLOCK TABLES;
COMMIT;这确实意味着，执行长期运行的SELECT的事务(1)必须等待事务(2)完成其INSERT，并解锁其表。
否则，如果SELECT首先在进行中，则意味着事务(2)必须等待该事务完成。
解决办法
如果避免使用CREATE TABLE... SELECT或INSERT INTO... SELECT，则可以在没有锁争用的情况下填充临时表。也就是说，将SELECT的结果集返回到您的应用程序中，然后将这些行放到临时表中。这样，SELECT就不需要任何S锁了。
您可以在存储过程中对游标执行相同的操作。
另一种解决办法
作为@BrendanF注释，您还可以将事务隔离级别更改为READ提交，而不是默认的可重复读取。您可以全局更改默认事务隔离级别，也可以按会话逐一更改隔离级别。这稍微改变了事务的语义，因此您应该阅读其中的差异。
但它确实消除了SELECT在这些insert/select操作期间从表中读取表时执行S锁的需要。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/23768456
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