我有一个基于Mediacore的网站因为更新查询而陷入困境。这些更新查询一直在运行，但有时（我相信，在高流量时段），其中一个更新会卡住，锁定所有其他查询：
245 mediacore_user localhost mediacore Query 36 Locked UPDATE media SET modified_on='2011-12-21 09:42:58', views=(media.views + 1) WHERE media.id = 1048
246 mediacore_user localhost mediacore Query 36 Locked UPDATE media SET modified_on='2011-12-21 09:42:58', views=(media.views + 1) WHERE media.id = 1048
248 mediacore_user localhost mediacore Query 36 Updating UPDATE media SET modified_on='2011-12-21 09:42:58', views=(media.views + 1) WHERE media.id = 1048
249 mediacore_user localhost mediacore Query 36 Locked UPDATE media SET modified_on='2011-12-21 09:42:58', views=(media.views + 1) WHERE media.id = 1048
253 mediacore_user localhost mediacore Query 36 Locked UPDATE media SET modified_on='2011-12-21 09:42:58', views=(media.views + 1) WHERE media.id = 1048
258 mediacore_user localhost mediacore Query 30 Locked UPDATE media SET modified_on='2011-12-21 09:43:04', views=(media.views + 1) WHERE media.id = 416
268 mediacore_user localhost mediacore Query 3 Locked UPDATE media SET modified_on='2011-12-21 09:43:31', views=(media.views + 1) WHERE media.id = 1048
269 mediacore_user localhost mediacore Query 3 Locked UPDATE media SET modified_on='2011-12-21 09:43:31', views=(media.views + 1) WHERE media.id = 1048
270 mediacore_user localhost mediacore Query 3 Locked UPDATE media SET modified_on='2011-12-21 09:43:31', views=(media.views + 1) WHERE media.id = 1048
271 mediacore_user localhost mediacore Query 3 Locked UPDATE media SET modified_on='2011-12-21 09:43:31', views=(media.views + 1) WHERE media.id = 1048
272 mediacore_user localhost mediacore Query 1 Locked UPDATE media SET modified_on='2011-12-21 09:43:33', views=(media.views + 1) WHERE media.id = 1048
如果我终止“正在更新”连接，另一个连接会被卡住，依此类推，直到只有大约3个查询被锁定。
有什么想法吗？
媒体表：
CREATE TABLE `media` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`type` varchar(8) DEFAULT NULL,
`slug` varchar(50) NOT NULL,
`podcast_id` int(11) DEFAULT NULL,
`reviewed` tinyint(1) NOT NULL,
`encoded` tinyint(1) NOT NULL,
`publishable` tinyint(1) NOT NULL,
`created_on` datetime NOT NULL,
`modified_on` datetime NOT NULL,
`publish_on` datetime DEFAULT NULL,
`publish_until` datetime DEFAULT NULL,
`title` varchar(255) NOT NULL,
`subtitle` varchar(255) DEFAULT NULL,
`description` text,
`description_plain` text,
`notes` text,
`duration` int(11) NOT NULL,
`views` int(11) NOT NULL,
`likes` int(11) NOT NULL,
`popularity_points` int(11) NOT NULL,
`author_name` varchar(50) NOT NULL,
`author_email` varchar(255) NOT NULL,
`dislikes` int(11) NOT NULL,
`popularity_likes` int(11) NOT NULL,
`popularity_dislikes` int(11) NOT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `slug` (`slug`),
KEY `podcast_id` (`podcast_id`),
CONSTRAINT `media_ibfk_1` FOREIGN KEY (`podcast_id`) REFERENCES `podcasts` (`id`) ON DELETE SET NULL ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=1049 DEFAULT CHARSET=utf8
INNODB问题发生后的状态：
=====================================
111221 12:12:09 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 6 seconds
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 78, signal count 78
Mutex spin waits 0, rounds 453, OS waits 17
RW-shared spins 122, OS waits 61; RW-excl spins 0, OS waits 0
------------
TRANSACTIONS
------------
Trx id counter 0 1115749
Purge done for trx's n:o < 0 1115735 undo n:o < 0 0
History list length 13
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0 1115747, not started, process no 15360, OS thread id 140486827099904
MySQL thread id 111, query id 11647 localhost mediacore_user
---TRANSACTION 0 0, not started, process no 15360, OS thread id 140486827898624
MySQL thread id 106, query id 11651 localhost root
show innodb status
---TRANSACTION 0 1115709, not started, process no 15360, OS thread id 140486826567424
MySQL thread id 103, query id 10874 localhost mediacore_user
---TRANSACTION 0 1115731, not started, process no 15360, OS thread id 140486792349440
MySQL thread id 102, query id 11517 localhost mediacore_user
---TRANSACTION 0 1115668, not started, process no 15360, OS thread id 140486792881920
MySQL thread id 101, query id 10067 localhost 127.0.0.1 a7user
---TRANSACTION 0 1115737, not started, process no 15360, OS thread id 140486791816960
MySQL thread id 95, query id 11578 localhost mediacore_user
---TRANSACTION 0 1115738, not started, process no 15360, OS thread id 140486827366144
MySQL thread id 87, query id 11577 localhost mediacore_user
---TRANSACTION 0 1115744, not started, process no 15360, OS thread id 140486827632384
MySQL thread id 61, query id 11606 localhost mediacore_user
---TRANSACTION 0 1115746, not started, process no 15360, OS thread id 140486826301184
MySQL thread id 22, query id 11633 localhost mediacore_user
---TRANSACTION 0 1115748, ACTIVE 1 sec, process no 15360, OS thread id 140486826833664
mysql tables in use 1, locked 1
MySQL thread id 55, query id 11650 localhost mediacore_user Table lock
UPDATE media SET modified_on='2011-12-21 12:12:08', dislikes=10 WHERE media.id = 572
Trx read view will not see trx with id >= 0 1115749, sees < 0 1115740
---TRANSACTION 0 1115743, ACTIVE 14 sec, process no 15360, OS thread id 140486826034944
mysql tables in use 1, locked 1
MySQL thread id 23, query id 11601 localhost mediacore_user Table lock
UPDATE media SET modified_on='2011-12-21 12:11:55', views=(media.views + 1) WHERE media.id = 1048
Trx read view will not see trx with id >= 0 1115744, sees < 0 1115740
---TRANSACTION 0 1115742, ACTIVE 14 sec, process no 15360, OS thread id 140486825502464
mysql tables in use 1, locked 1
MySQL thread id 90, query id 11599 localhost mediacore_user Table lock
UPDATE media SET modified_on='2011-12-21 12:11:55', views=(media.views + 1) WHERE media.id = 1048
Trx read view will not see trx with id >= 0 1115743, sees < 0 1115740
---TRANSACTION 0 1115741, ACTIVE 14 sec, process no 15360, OS thread id 140486825768704 starting index read
mysql tables in use 1, locked 1
LOCK WAIT 2 lock struct(s), heap size 368, 1 row lock(s)
MySQL thread id 73, query id 11596 localhost mediacore_user Updating
UPDATE media SET modified_on='2011-12-21 12:11:55', views=(media.views + 1) WHERE media.id = 1048
Trx read view will not see trx with id >= 0 1115742, sees < 0 1115740
------- TRX HAS BEEN WAITING 14 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 0 page no 1025 n bits 88 index `PRIMARY` of table `mediacore`.`media` trx id 0 1115741 lock_mode X locks rec but not gap waiting
Record lock, heap no 20 PHYSICAL RECORD: n_fields 27; compact format; info bits 0
0: len 4; hex 80000418; asc ;; 1: len 6; hex 00000011065c; asc \;; 2: len 7; hex 00000003c20d5b; asc [;; 3: len 5; hex 766964656f; asc video;; 4: len 30; hex 617273656c696f2d7061746f2d64652d63617276616c686f2d686f6d656e; asc arselio-pato-de-carvalho-homen;...(truncated); 5: len 4; hex 80000013; asc ;; 6: len 1; hex 81; asc ;; 7: len 1; hex 81; asc ;; 8: len 1; hex 81; asc ;; 9: len 8; hex 8000124a82217b0b; asc J !{ ;; 10: len 8; hex 8000124a8230e083; asc J 0 ;; 11: len 8; hex 8000124a82220ef0; asc J " ;; 12: SQL NULL; 13: len 30; hex 417273c3a96c696f205061746f2064652043617276616c686f20686f6d65; asc Ars lio Pato de Carvalho home;...(truncated); 14: SQL NULL; 15: len 30; hex 3c703e43656e74726f206465204e6575726f6369c3aa6e63696173206520; asc <p>Centro de Neuroci ncias e ;...(truncated); 16: len 30; hex 43656e74726f206465204e6575726f6369c3aa6e6369617320652042696f; asc Centro de Neuroci ncias e Bio;...(truncated); 17: SQL NULL; 18: len 4; hex 80000000; asc ;; 19: len 4; hex 80000099; asc ;; 20: len 4; hex 80000000; asc ;; 21: len 4; hex 80000000; asc ;; 22: len 3; hex 554356; asc UCV;; 23: len 9; hex 7563764075632e7074; asc ucv@uc.pt;; 24: len 4; hex 80000000; asc ;; 25: len 4; hex 80000000; asc ;; 26: len 4; hex 80000000; asc ;;
------------------
---TRANSACTION 0 1115740, ACTIVE 14 sec, process no 15360, OS thread id 140486792083200
2 lock struct(s), heap size 368, 1 row lock(s), undo log entries 1
MySQL thread id 97, query id 11597 localhost mediacore_user Table lock
SELECT 1
FROM media_fulltext
LIMIT 1
Trx read view will not see trx with id >= 0 1115741, sees < 0 1115741
--------
FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (write thread)
Pending normal aio reads: 0, aio writes: 0,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
187 OS file reads, 469 OS file writes, 298 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 inserts, 0 merged recs, 0 merges
Hash table size 2212699, node heap has 9 buffer(s)
0.17 hash searches/s, 0.17 non-hash searches/s
---
LOG
---
Log sequence number 0 148655397
Log flushed up to 0 148655397
Last checkpoint at 0 148655397
0 pending log writes, 0 pending chkp writes
177 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 1225697720; in additional pool allocated 11846912
Dictionary memory allocated 203840
Buffer pool size 65536
Free buffers 65299
Database pages 228
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages read 225, created 3, written 259
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 1000 / 1000
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
6 read views open inside InnoDB
Main thread process no. 15360, id 140486801540864, state: sleeping
Number of rows inserted 13, updated 85, deleted 2, read 281971
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.17 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
编辑：不知何故，有些更新在提交后没有解锁表。我查看了很长时间的查询，并在50秒后看到锁被释放并执行了一次更新。我已经将innodb_lock_wait_timeout更改为5并且我看到了同样的事情，只有5秒而不是50秒的间隔。但是一旦它只有几个更新被锁定，它们都被瞬间执行......这是一种非常奇怪的行为...
答案 0 :(得分：0)
我认为这是因为一次有大量查询。尝试在您的字段中使用mysql index。它会加快表现。
答案 1 :(得分：0)
有点晚了，但我想补充一些信息：从我的观察来看，如果您启用了全文索引，就会发生这种情况。在这种情况下，MySQL中涉及InnoDB（媒体表）和MyISAM（全文索引）锁定的交互似乎不好。
如果没有安装MediaCore的全文触发器，我从未见过这个问题。