我发现许多人从MySQL获得了相同的错误消息，错误状态= 41000 amd，同样的错误代码= 1205。
然而，其中大多数都涉及2次交易和死锁。
基于SHOW ENGINE INNODB STATUS输出，只有一个事务：
===================================== 140715 4:42:37 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 21 seconds ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 1630, signal count 1612 Mutex spin waits 0, rounds 10461, OS waits 205 RW-shared spins 2051, OS waits 1024; RW-excl spins 407, OS waits 380 ------------ TRANSACTIONS ------------ Trx id counter 0 8450727 Purge done for trx's n:o < 0 8450719 undo n:o < 0 0 History list length 10 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 0 0, not started, process no 8967, OS thread id 140114720237312 MySQL thread id 31142, query id 6206904 localhost root SHOW ENGINE INNODB STATUS ---TRANSACTION 0 8450588, not started, process no 8967, OS thread id 140114589861632 MySQL thread id 30909, query id 6153062 [my IP] [my username] ---TRANSACTION 0 8450484, not started, process no 8967, OS thread id 140114719172352 MySQL thread id 30899, query id 6152893 [my IP] [my username] ---TRANSACTION 0 8450702, not started, process no 8967, OS thread id 140114586134272 MySQL thread id 28747, query id 6206903 [my IP] [my username] ---TRANSACTION 0 8450726, ACTIVE 34 sec, process no 8967, OS thread id 140114484233984 inserting mysql tables in use 1, locked 1 LOCK WAIT 3 lock struct(s), heap size 1216, 1 row lock(s) MySQL thread id 31147, query id 6206832 [my IP] [my username] update INSERT INTO [My table] [the rest of the statement....] ------- TRX HAS BEEN WAITING 34 SEC FOR THIS LOCK TO BE GRANTED: RECORD LOCKS space id 0 page no 45066 n bits 432 index `PRIMARY` of table `[My DB]`.`[some table]` trx id 0 8450726 lock mode S locks rec but not gap waiting Record lock, heap no 359 PHYSICAL RECORD: n_fields 6; compact format; info bits 0 0: len 8; hex 000000000000bdca; asc ;; 1: len 6; hex 00000080f2a0; asc ;; 2: len 7; hex 80000000390110; asc 9 ;; 3: len 6; hex 73797374656d; asc system;; 4: len 1; hex 02; asc ;; 5: len 4; hex 53c4b11b; asc S ;; ------------------ ---TRANSACTION 0 8450725, ACTIVE 35 sec, process no 8967, OS thread id 140114588530432 MySQL thread id 31146, query id 6206822 [my IP] [my username] Trx read view will not see trx with id >= 0 8450726, sees < 0 8450720 ---TRANSACTION 0 8450720, ACTIVE 36 sec, process no 8967, OS thread id 140114590127872 393 lock struct(s), heap size 47088, 31495 row lock(s), undo log entries 229 MySQL thread id 31145, query id 6206823 [my IP] [my username] -------- 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 10744 OS file reads, 25629 OS file writes, 18087 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 5, seg size 7, 519 inserts, 519 merged recs, 76 merges Hash table size 17393, node heap has 12 buffer(s) 0.00 hash searches/s, 0.00 non-hash searches/s --- LOG --- Log sequence number 5 2505544157 Log flushed up to 5 2505544157 Last checkpoint at 5 2505544157 0 pending log writes, 0 pending chkp writes 15981 log i/o's done, 0.00 log i/o's/second ---------------------- BUFFER POOL AND MEMORY ---------------------- Total memory allocated 21017578; in additional pool allocated 1048576 Dictionary memory allocated 466176 Buffer pool size 512 Free buffers 0 Database pages 498 Modified db pages 0 Pending reads 0 Pending writes: LRU 0, flush list 0, single page 0 Pages read 12504, created 289, written 10838 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 2 read views open inside InnoDB Main thread process no. 8967, id 140114495788800, state: waiting for server activity Number of rows inserted 38311, updated 16430, deleted 36, read 6456822 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s ---------------------------- END OF INNODB MONITOR OUTPUT ============================
mysql> SELECT @@GLOBAL.tx_isolation, @@tx_isolation, @@session.tx_isolation;
+-----------------------+-----------------+------------------------+
| @@GLOBAL.tx_isolation | @@tx_isolation | @@session.tx_isolation |
+-----------------------+-----------------+------------------------+
| REPEATABLE-READ | REPEATABLE-READ | REPEATABLE-READ |
+-----------------------+-----------------+------------------------+
1 row in set (0.00 sec)
如果我建立自动提交设置为true的连接（我正在使用Apache Common DBCP 1.4），则此问题不存在。
答案 0 :(得分：0)
我发现了这个问题。
问题是MySQL期望同一事务中的所有查询都在同一个TCP连接中完成，而每个通过QueryRunner执行的SQL都可能启动到数据库的新TCP连接（尽管可以通过多种方式控制）。