ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
問題描述：
研發忽然找我，遇到了mysql的 ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction，具體報錯以下：html
org.apache.hadoop.mapred.YarnChild.main(YarnChild.java:158) Caused by: java.io .IOException: java.sql.SQLException: Lock wait timeout exceeded;
try restarting transaction at org.apache.sqoop.mapreduce.AsyncSqlRecordWriter.write(AsyncSqlRecordWriter.java:220)
at org.apache.sqoop.mapreduce.AsyncSqlRecordWriter.write(AsyncSqlRecordWriter.java:46) at
org.apache.hadoop.mapred.MapTask$NewDirectOutputCollector.write(MapTask.java:655) at
產生這個問題的緣由是由於在mysql中產生了事務A，執行了修改的語句，好比： update t1 set aget=18 where id=1;此時事務並未進行提交，事務B開始運行，也一樣須要修改id爲1的用戶的年齡： update t1 set aget=20 where id=1; 那麼此時事務B會等待事務A結束釋放寫鎖才能執行成功，不然則會等待一段時間，產生報錯：java
ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transactionnode
下面開始模擬鎖表的場景：mysql
1、打開一個終端，鏈接上mysql，關閉事務自動提交，執行一個update語句
查看鏈接的id：sql
2、打開另一個終端，用mysql鏈接上去，更新一步驟中的update的那條數據，
而後等待一會，會報ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction數據庫
3、再打開一個終端鏈接上去，查看鎖的狀態
在mysql5.5以後，information_schema數據庫加了三個關於鎖的表apache
innodb_trx ## 當前運行的全部事務bash
innodb_locks ## 當前出現的鎖服務器
innodb_lock_waits ## 鎖等待的對應關係dom
這個表對於排查由於事務未提交引發的鎖問題能夠說是舉足輕重。當咱們有事務長時間未提交致使鎖住數據庫，其餘程序拿不到鎖的時候，由於對這張表進行排查。
經過這個表咱們能夠查出鏈接的線程ID，可根據時間判斷懷疑一下
SELECT * FROM information_schema.INNODB_TRX\G
好比咱們獲取一條記錄的線程id， 便可拿着該線程id去information_schma.processlist中獲取他的具體狀況
咱們能夠經過以下的方法找出鏈接的服務器，進而判斷進程：
此處host能夠出現端口，而後再用lsof –p $port 來查看是哪一個程序，基本上就能夠確認了，是哪一個程序搞的鬼，接下來看下記錄鎖信息的表 innodb_locks
若是 咱們要排查的問題正鎖死咱們的某張表，那麼該表的數據表就會有所體現。同時和這個表使用的 還有information_schema.innodb_lock_waits
此時若是咱們要想恢復，能夠手動殺掉id9的鏈接，若是是死鎖的狀況下。
在第一個終端查看：
注意：若是咱們若是有權限，可使用能看到相對來講更爲複雜和詳細的信息
4、其餘排查手段
#經過innodb status 提供的詳細的系統狀況來分析問題。
SHOW ENGINE INNODB STATUS\G
若是我沒沒有使用show engine innodb status的權限，退而求其次咱們可使用另一種思路來找到是哪一個表持續被鎖，致使拿不到鎖的問題。
show open tables where in_use>0;
查看如今系統正在使用的表，而後使用：
show full processlist;
查找正在query該表的任務，查看代碼是否有一直沒有提交事物，卻沒有commit的代碼，用這個思路來找問題出如今哪兒。
mysql> show engine innodb status\G *************************** 1. row *************************** Type: InnoDB Name: Status: ===================================== 2017-08-08 22:39:01 0x7fde3ce46700 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 37 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 13 srv_active, 0 srv_shutdown, 1407 srv_idle srv_master_thread log flush and writes: 1420 ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 44 OS WAIT ARRAY INFO: signal count 44 RW-shared spins 0, rounds 56, OS waits 28 RW-excl spins 0, rounds 0, OS waits 0 RW-sx spins 0, rounds 0, OS waits 0 Spin rounds per wait: 56.00 RW-shared, 0.00 RW-excl, 0.00 RW-sx ------------ TRANSACTIONS ------------ Trx id counter 1305 Purge done for trx's n:o < 1303 undo n:o < 0 state: running but idle History list length 6 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 422074379878000, not started 0 lock struct(s), heap size 1136, 0 row lock(s) ---TRANSACTION 422074379876176, not started 0 lock struct(s), heap size 1136, 0 row lock(s) ---TRANSACTION 1303, ACTIVE 238 sec 2 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 1 MySQL thread id 9, OS thread handle 140592481601280, query id 101 localhost root Trx read view will not see trx with id >= 1303, sees < 1303 -------- 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] , aio writes: [0, 0, 0, 0] , ibuf aio reads:, log i/o's:, sync i/o's: Pending flushes (fsync) log: 0; buffer pool: 0 274 OS file reads, 245 OS file writes, 165 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 mark 0, delete 0 Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) Hash table size 1593743, node heap has 0 buffer(s) 0.00 hash searches/s, 0.00 non-hash searches/s --- LOG --- Log sequence number 2549841 Log flushed up to 2549841 Pages flushed up to 2549841 Last checkpoint at 2549832 0 pending log flushes, 0 pending chkp writes 78 log i/o's done, 0.00 log i/o's/second ---------------------- BUFFER POOL AND MEMORY ---------------------- Total large memory allocated 6596591616 Dictionary memory allocated 342962 Buffer pool size 393192 Free buffers 392904 Database pages 288 Old database pages 0 Modified db pages 0 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 242, created 46, written 111 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: 288, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---------------------- INDIVIDUAL BUFFER POOL INFO ---------------------- ---BUFFER POOL 0 Buffer pool size 49146 Free buffers 49106 Database pages 40 Old database pages 0 Modified db pages 0 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 40, created 0, written 27 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: 40, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 1 Buffer pool size 49152 Free buffers 49144 Database pages 8 Old database pages 0 Modified db pages 0 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 8, created 0, written 0 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: 8, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 2 Buffer pool size 49146 Free buffers 49137 Database pages 9 Old database pages 0 Modified db pages 0 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 9, created 0, written 0 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: 9, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 3 Buffer pool size 49152 Free buffers 49076 Database pages 76 Old database pages 0 Modified db pages 0 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 76, created 0, written 6 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: 76, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 4 Buffer pool size 49146 Free buffers 49055 Database pages 91 Old database pages 0 Modified db pages 0 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 85, created 6, written 17 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: 91, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 5 Buffer pool size 49152 Free buffers 49140 Database pages 12 Old database pages 0 Modified db pages 0 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 11, created 1, written 3 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: 12, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 6 Buffer pool size 49146 Free buffers 49106 Database pages 40 Old database pages 0 Modified db pages 0 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 5, created 35, written 43 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: 40, unzip_LRU len: 0 I/O sum[0]:cur[0], unzip sum[0]:cur[0] ---BUFFER POOL 7 Buffer pool size 49152 Free buffers 49140 Database pages 12 Old database pages 0 Modified db pages 0 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 8, created 4, written 15 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: 12, 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 1 read views open inside InnoDB Process ID=17616, Main thread ID=140591056803584, state: sleeping Number of rows inserted 6, updated 5, deleted 0, read 48 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s ---------------------------- END OF INNODB MONITOR OUTPUT ============================