डिबग लॉक वेट टाइमआउट स्थिति कुछ थ्रेड्स के कारण होती है। यदि एक थ्रेड बहुत लंबे समय तक कुछ रिकॉर्ड्स को होल्ड करके रखता है, तो इसका मतलब है कि थ्रेड ने समय सीमा पार कर ली है।
सभी विवरण देखने के लिए, निम्नलिखित क्वेरी लागू करें:
mysql> SHOW ENGINE INNODB STATUS;
निम्नलिखित आउटपुट है।
+--------+------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Type | Name | Status | +--------+------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | InnoDB | | ===================================== 2018-10-23 09:55:05 0x19e8 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 7 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 2 srv_active, 0 srv_shutdown, 17805 srv_idle srv_master_thread log flush and writes: 0 ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 3 OS WAIT ARRAY INFO: signal count 3 RW-shared spins 0, rounds 0, OS waits 0 RW-excl spins 0, rounds 0, OS waits 0 RW-sx spins 0, rounds 0, OS waits 0 Spin rounds per wait: 0.00 RW-shared, 0.00 RW-excl, 0.00 RW-sx ------------ TRANSACTIONS ------------ Trx id counter 21000 Purge done for trx's n:o < 20998 undo n:o < 0 state: running but idle History list length 3 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 283438498772800, not started 0 lock struct(s), heap size 1136, 0 row lock(s) -------- FILE I/O -------- I/O thread 0 state: wait Windows aio (insert buffer thread) I/O thread 1 state: wait Windows aio (log thread) I/O thread 2 state: wait Windows aio (read thread) I/O thread 3 state: wait Windows aio (read thread) I/O thread 4 state: wait Windows aio (read thread) I/O thread 5 state: wait Windows aio (read thread) I/O thread 6 state: wait Windows aio (write thread) I/O thread 7 state: wait Windows aio (write thread) I/O thread 8 state: wait Windows aio (write thread) I/O thread 9 state: wait Windows aio (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 1025 OS file reads, 545 OS file writes, 11 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 2267, node heap has 0 buffer(s) Hash table size 2267, node heap has 1 buffer(s) Hash table size 2267, node heap has 3 buffer(s) Hash table size 2267, node heap has 1 buffer(s) Hash table size 2267, node heap has 0 buffer(s) Hash table size 2267, node heap has 0 buffer(s) Hash table size 2267, node heap has 0 buffer(s) Hash table size 2267, node heap has 0 buffer(s) Hash table size 2267, node heap has 0 buffer(s) 0.00 hash searches/s, 0.29 non-hash searches/s --- LOG --- Log sequence number 24309079 Log buffer assigned up to 24309079 Log buffer completed up to 24309079 Log written up to 24309079 Log flushed up to 24309079 Added dirty pages up to 24309079 Pages flushed up to 24309079 Last checkpoint at 24309079 388 log i/o's done, 0.00 log i/o's/second ---------------------- BUFFER POOL AND MEMORY ---------------------- Total large memory allocated 8585216 Dictionary memory allocated 361173 Buffer pool size 512 Free buffers 251 Database pages 256 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 1002, created 132, written 144 0.00 reads/s, 0.00 creates/s, 0.00 writes/s Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000 Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s LRU len: 256, 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 Process ID = 3260, Main thread ID = 000000000000106C , state = sleeping Number of rows inserted 0, updated 313, deleted 0, read 4534 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.14 reads/s ---------------------------- END OF INNODB MONITOR OUTPUT ============================ | +--------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) mysql>
उपरोक्त आउटपुट थ्रेड और I/O से संबंधित सभी विवरण दिखाता है।
व्यावहारिक सुझाव:SHOW ENGINE INNODB STATUSकाTRANSACTIONSसेक्शन लंबे समय से चल रहे लेनदेन और लॉक दिखाता है।performance_schema.data_locksऔरdata_lock_waits(MySQL 8.0+) लॉक जानकारी के लिए अधिक संरचित और क्वेरी योग्य दृश्य प्रदान करते हैं।innodb_lock_wait_timeout(डिफ़ॉल्ट 50 सेकंड) बढ़ाना अस्थायी समाधान है; मूल कारण (लंबे लेनदेन, लापता इंडेक्स) को ठीक करना बेहतर है।
