最近我面临着一个经常性的死锁，比如1K并发用户每分钟1到5次。以下查询称为每分钟平均2次和每位用户。
我不知道如何解决这个问题，因为这个查询是为了处理2个不同玩家（或同一玩家2次以上）执行插入查询时的可能竞争条件而构建的。
当然，我可以通过独特的键来处理竞争条件，但是在100多个搜索免费点的用户的高峰期是无法管理的。值得注意的是，它会通过重复密钥导致91次拒绝。
LATEST DETECTED DEADLOCK
------------------------
*** (1) TRANSACTION:
TRANSACTION 100539324, ACTIVE 0 sec inserting
mysql tables in use 5, locked 5
LOCK WAIT 23 lock struct(s), heap size 3520, 111 row lock(s), undo log entries 1
MySQL thread id 6782, OS thread handle 2460, query id 138188765 localhost 127.0.0.1 root Creating sort index
INSERT INTO app_tables_players (user_id, game_id, seat_number, username, state, folded) SELECT 597, a.id, b.id AS seat_number, 'some_username', 'temp', false FROM (SELECT id FROM app_tables_games WHERE table_id = 6 AND seats_total > seats_taken AND id NOT IN (SELECT game_id FROM app_users_state WHERE user_id = 597)) AS a, `app_temp_players_9` AS b WHERE b.id NOT IN (SELECT seat_number FROM app_tables_players WHERE game_id = a.id) ORDER BY a.id ASC LIMIT 1
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 75 page no 51 n bits 1120 index seat_number_game_id of table `nodejs`.`app_tables_players` trx id 100539324 lock_mode X locks gap before rec insert intention waiting
Record lock, heap no 964 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d8f6; asc ;;
2: len 4; hex 006b437b; asc kC{;;
*** (2) TRANSACTION:
TRANSACTION 100539325, ACTIVE 0 sec setting auto-inc lock, thread declared inside InnoDB 4743
mysql tables in use 5, locked 5
22 lock struct(s), heap size 3520, 151 row lock(s)
MySQL thread id 6702, OS thread handle 11428, query id 138188764 localhost 127.0.0.1 root Creating sort index
INSERT INTO app_tables_players (user_id, game_id, seat_number, username, state, folded) SELECT 613, a.id, b.id AS seat_number, 'some_username2', 'tmp', false FROM (SELECT id FROM app_tables_games WHERE table_id = 14 AND seats_total > seats_taken AND id NOT IN (SELECT game_id FROM app_users_state WHERE user_id = 613)) AS a, `app_temp_players_9` AS b WHERE b.id NOT IN (SELECT seat_number FROM app_tables_players WHERE game_id = a.id) ORDER BY a.id ASC LIMIT 1
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 75 page no 51 n bits 1120 index seat_number_game_id of table `nodejs`.`app_tables_players` trx id 100539325 lock mode S locks gap before rec
Record lock, heap no 18 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 06; asc ;;
1: len 4; hex 0008d6e4; asc ;;
2: len 4; hex 006b5a47; asc kZG;;
Record lock, heap no 97 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d97e; asc ~;;
2: len 4; hex 006b5d1e; asc k] ;;
Record lock, heap no 160 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 05; asc ;;
1: len 4; hex 0008d93e; asc >;;
2: len 4; hex 006b4cb3; asc kL ;;
Record lock, heap no 181 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d92f; asc /;;
2: len 4; hex 006b5c0b; asc k\ ;;
Record lock, heap no 267 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d9b2; asc ;;
2: len 4; hex 006b5b9a; asc k[ ;;
Record lock, heap no 272 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 05; asc ;;
1: len 4; hex 0008d999; asc ;;
2: len 4; hex 006b5d43; asc k]C;;
Record lock, heap no 307 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008da33; asc 3;;
2: len 4; hex 006b6182; asc ka ;;
Record lock, heap no 346 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008da38; asc 8;;
2: len 4; hex 006b5fbd; asc k_ ;;
Record lock, heap no 530 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 05; asc ;;
1: len 4; hex 0008d9b2; asc ;;
2: len 4; hex 006b544e; asc kTN;;
Record lock, heap no 556 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 05; asc ;;
1: len 4; hex 0008d97e; asc ~;;
2: len 4; hex 006b62f3; asc kb ;;
Record lock, heap no 629 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d999; asc ;;
2: len 4; hex 006b5f41; asc k_A;;
Record lock, heap no 804 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 05; asc ;;
1: len 4; hex 0008da33; asc 3;;
2: len 4; hex 006b60bc; asc k` ;;
Record lock, heap no 906 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d93e; asc >;;
2: len 4; hex 006b4988; asc kI ;;
Record lock, heap no 962 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d928; asc (;;
2: len 4; hex 006b5b03; asc k[ ;;
Record lock, heap no 964 PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 1; hex 04; asc ;;
1: len 4; hex 0008d8f6; asc ;;
2: len 4; hex 006b437b; asc kC{;;
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
TABLE LOCK table `nodejs`.`app_tables_players` trx id 100539325 lock mode AUTO-INC waiting
*** WE ROLL BACK TRANSACTION (2)
导致问题的查询：
INSERT INTO app_tables_players
(user_id,
game_id,
seat_number)
SELECT
597,
a.id,
b.id AS seat_number
FROM
(SELECT id
FROM
app_tables_games
WHERE
table_id = 14
AND seats_total > seats_taken
AND id NOT IN (
SELECT game_id
FROM app_users_state
WHERE user_id = 597
)
) AS a,
app_temp_players_9 AS b
WHERE
b.id NOT IN (
SELECT seat_number
FROM app_tables_players
WHERE game_id = a.id
)
ORDER BY a.id ASC
LIMIT 1;
id, select_type, table, partitions, type, possible_keys, key, key_len, ref, rows, filtered, Extra
1, INSERT, app_tables_players, , ALL, , , , , , ,
1, PRIMARY, app_tables_games, , ref, table_id,table_id_seats_taken_seats_total, table_id_seats_taken_seats_total, 4, const, 24, 33.33, Using where; Using index; Using temporary; Using filesort
1, PRIMARY, b, , index, , id, 1, , 9, 100.00, Using where; Using index; Using join buffer (Block Nested Loop)
4, DEPENDENT SUBQUERY, app_tables_players, , index_subquery, seat_number_game_id,game_id_user_id,game_id,seat_number,game_id_state, seat_number_game_id, 6, func,func, 2, 100.00, Using where; Using index
3, SUBQUERY, app_users_state, , ref, game_id_user_id,user_id,game_id, user_id, 4, const, 4, 100.00,
注意：有时上述查询会发生死锁，并且：
DELETE FROM app_users_states WHERE game_id = some_id AND user_id = some_id
答案 0 :(得分：-1)
在对该应用程序中遇到的所有死锁进行更多研究之后，我发现有2-3种不同的类型或情况。
其中一个是lock mode AUTO-INC waiting
因此，第一个事务将自动增量id列锁定并等待索引'X'，第二个事务锁定索引'X'并等待AUTO-INC锁定。
由于我需要id列来获取lastInsertId并稍后在SELECT中使用它，因此必须拥有此自动增量列。为了解决这个问题，我在我的应用程序中创建了一个已知的UUID值并存储为二进制（16）而不是自动增量int id。
第二个问题与同一查询中不同或相同表格中INSERT上的SELECT有关。喜欢（siple例子）;
INSERT INTO tableA some_colX (SELECT some_colY FROM tableA WHERE some_colZ = 1 LIMIT 1)
此SELECT使用了lock mode S locks gap before rec，但INSERT需要lock_mode X locks gap before rec insert intention waiting。在我的INSERT我在3个不同的表中执行SELECT，在应用程序的其他部分中有一些其他UPDATE s或其他INSERT s，所以很多死锁无处不在。
为了解决部分问题，我在SELECT语句中添加了INSERT {更改了FOR UPDATE，因此添加了IX lock，而不是S lock阻止其他查询首先获得X lock in this record/gap
我后来意识到，我的应用程序中还有另一个死锁。你认为呢？在其他完全不同的表中查询INSERT上的另一个不同的（和最新的）SELECT。
从每分钟1到5个死锁到每10分钟或更长时间1个死锁。
因此，作为我的个人意见（用例），请勿在同一查询中使用INSERT和SELECT。使用过程，事务......并检查SELECT是否正在使用正确的索引。
对不起我的英文：）
祝你好运。更新：
主表中的第1个索引涉及INSERT表中的一个SELECT和1个索引。结果：到目前为止，2小时内有0个死锁