问题描述
在当前应用程序中，我们使用通过主键从表中选择的模式，如果它不返回数据，则在其中插入新行。当我们执行选择时，我们使用事务并使用“选择更新”语句。
我们发现有时插入操作将出现死锁。我高度怀疑这是由于第一个“选择更新”没有返回任何行。这就是为什么我要问的问题，如果我们使用select进行更新，并且使用不存在的主键，那么哪些行将被锁定？整个桌子都被锁住了吗？
我们使用Golang和github.com/jmoiron/sqlx和github.com/volatiletech/sqlboiler进行数据库操作。但是伪代码是：
// Creation API
func handle_create_request(payload) {
id = gen_new_id()
dao_upsert(id,payload)
}
// for Creation API and Update API
func dao_upsert(id,payload) {
tx = start_db_transaction()
record = select_for_update(id,tx)
if record == nil {
record = gen_new_record(id,payload)
upsert_record(record,tx) // <--- Error throws: Error 1213: Deadlock
found when trying to get lock; try restarting transaction
}
finalize_transaction(tx)
}
SHOW VARIABLES LIKE '%version%'; 我们的数据库版本
'aurora_version','2.04.4'
'innodb_version','5.7.12'
'protocol_version','10'
'slave_type_conversions',''
'tls_version','TLSv1,TLSv1.1,TLSv1.2'
'version','5.7.12'
'version_comment','MySQL Community Server (GPL)'
'version_compile_machine','x86_64'
'version_compile_os','Linux'
解决方法
这个ist不是Anwser，只需要发表评论即可。
InnoDB Engine是基于行的锁，但是我看不到表的创建。 解除锁定后，您可以查看哪些任务给您带来了僵局。
MariaDB [(none)]> show engine innodb status;
+--------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Type | Name | Status |
+--------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| InnoDB | |
=====================================
2020-10-07 19:05:49 7fcf12830700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 34 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 8 srv_active,0 srv_shutdown,1766546 srv_idle
srv_master_thread log flush and writes: 1766306
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 29
OS WAIT ARRAY INFO: signal count 27
Mutex spin waits 43,rounds 1290,OS waits 12
RW-shared spins 17,rounds 510,OS waits 17
RW-excl spins 0,rounds 0,OS waits 0
Spin rounds per wait: 30.00 mutex,30.00 RW-shared,0.00 RW-excl
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2020-09-17 09:58:49 7fcf12862700 Error in foreign key constraint of table `bernd`.`table_b`:
Create table `bernd`.`table_b` with foreign key constraint failed. Referenced table `bernd`.`table_a` not found in the data dictionary near ' FOREIGN KEY (table_a_id) REFERENCES table_a (id) )'.
------------
TRANSACTIONS
------------
Trx id counter 6201
Purge done for trx's n:o < 6196 undo n:o < 0 state: running but idle
History list length 37
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0,not started
MySQL thread id 63,OS thread handle 0x7fcf12830700,query id 279 localhost root init
show engine innodb status
---TRANSACTION 6147,not started
MySQL thread id 1,OS thread handle 0x7fcf12894700,query id 0 Waiting for requests
--------
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],aio writes: 0 [0,ibuf aio reads: 0,log i/o's: 0,sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
374 OS file reads,156 OS file writes,80 OS fsyncs
0.00 reads/s,0 avg bytes/read,0.00 writes/s,0.00 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1,free list len 0,seg size 2,0 merges
merged operations:
insert 0,delete mark 0,delete 0
discarded operations:
insert 0,delete 0
0.00 hash searches/s,0.00 non-hash searches/s
---
LOG
---
Log sequence number 149277494
Log flushed up to 149277494
Pages flushed up to 149277494
Last checkpoint at 149277494
Max checkpoint age 80826164
Checkpoint age target 78300347
Modified age 0
Checkpoint age 0
0 pending log writes,0 pending chkp writes
39 log i/o's done,0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 140574720; in additional pool allocated 0
Total memory allocated by read views 104
Internal hash tables (constant factor + variable factor)
Adaptive hash index 2217568 (2213368 + 4200)
Page hash 139112 (buffer pool 0 only)
Dictionary cache 632352 (554768 + 77584)
File system 830352 (812272 + 18080)
Lock system 333592 (332872 + 720)
Recovery system 0 (0 + 0)
Dictionary memory allocated 77584
Buffer pool size 8191
Buffer pool size,bytes 134201344
Free buffers 7825
Database pages 366
Old database pages 0
Modified db pages 0
Percent of dirty pages(LRU & free pages): 0.000
Max dirty pages percent: 75.000
Pending reads 0
Pending writes: LRU 0,flush list 0,single page 0
Pages made young 0,not young 0
0.00 youngs/s,0.00 non-youngs/s
Pages read 346,created 20,written 102
0.00 reads/s,0.00 creates/s,0.00 writes/s
No buffer pool page gets since the last printout
Pages read ahead 0.00/s,evicted without access 0.00/s,Random read ahead 0.00/s
LRU len: 366,unzip_LRU len: 0
I/O sum[0]:cur[0],unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB,0 queries in queue
0 read views open inside InnoDB
0 RW transactions active inside InnoDB
0 RO transactions active inside InnoDB
0 out of 1000 descriptors used
Main thread process no. 113887,id 140526766503680,state: sleeping
Number of rows inserted 10,updated 0,deleted 0,read 10
0.00 inserts/s,0.00 updates/s,0.00 deletes/s,0.00 reads/s
Number of system rows inserted 0,read 0
0.00 inserts/s,0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
|
+--------+------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.05 sec)
MariaDB [(none)]>
我不确定您要创建或更新什么，但是通常您可以使用一个statemant来完成。如果存在任何唯一键，则下一条语句将更新一条记录，否则将插入一条。
INSERT INTO table (a,b,c) VALUES (1,2,3),(4,5,6)
ON DUPLICATE KEY UPDATE c=VALUES(a)+VALUES(b);
设置时间 控制面板
错误1：Request method ‘DELETE‘ not supported 错误还原：...