MySQL 9.0 發行說明
鎖定監控器與標準監控器相同，但包含額外的鎖定資訊。啟用任一監控器以進行定期輸出會開啟相同的輸出串流，但如果啟用鎖定監控器，則串流會包含額外資訊。例如，如果您啟用標準監控器和鎖定監控器，則會開啟單一輸出串流。該串流會包含額外的鎖定資訊，直到您停用鎖定監控器為止。
使用 SHOW ENGINE INNODB STATUS 陳述式產生標準監控器輸出時，其限制為 1MB。此限制不適用於寫入伺服器標準錯誤輸出 (stderr) 的輸出。
標準監控器輸出範例
mysql> SHOW ENGINE INNODB STATUS\G
*************************** 1. row ***************************
Type: InnoDB
Name:
Status:
=====================================
2018-04-12 15:14:08 0x7f971c063700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 4 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 15 srv_active, 0 srv_shutdown, 1122 srv_idle
srv_master_thread log flush and writes: 0
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 24
OS WAIT ARRAY INFO: signal count 24
RW-shared spins 4, rounds 8, OS waits 4
RW-excl spins 2, rounds 60, OS waits 2
RW-sx spins 0, rounds 0, OS waits 0
Spin rounds per wait: 2.00 RW-shared, 30.00 RW-excl, 0.00 RW-sx
------------------------
LATEST FOREIGN KEY ERROR
------------------------
2018-04-12 14:57:24 0x7f97a9c91700 Transaction:
TRANSACTION 7717, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
4 lock struct(s), heap size 1136, 3 row lock(s), undo log entries 3
MySQL thread id 8, OS thread handle 140289365317376, query id 14 localhost root update
INSERT INTO child VALUES (NULL, 1), (NULL, 2), (NULL, 3), (NULL, 4), (NULL, 5), (NULL, 6)
Foreign key constraint fails for table `test`.`child`:
,
CONSTRAINT `child_ibfk_1` FOREIGN KEY (`parent_id`) REFERENCES `parent` (`id`) ON DELETE
CASCADE ON UPDATE CASCADE
Trying to add in child table, in index par_ind tuple:
DATA TUPLE: 2 fields;
0: len 4; hex 80000003; asc ;;
1: len 4; hex 80000003; asc ;;
But in parent table `test`.`parent`, in index PRIMARY,
the closest match we can find is record:
PHYSICAL RECORD: n_fields 3; compact format; info bits 0
0: len 4; hex 80000004; asc ;;
1: len 6; hex 000000001e19; asc ;;
2: len 7; hex 81000001110137; asc 7;;
------------
TRANSACTIONS
------------
Trx id counter 7748
Purge done for trx's n:o < 7747 undo n:o < 0 state: running but idle
History list length 19
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 421764459790000, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 7747, ACTIVE 23 sec starting index read
mysql tables in use 1, locked 1
LOCK WAIT 2 lock struct(s), heap size 1136, 1 row lock(s)
MySQL thread id 9, OS thread handle 140286987249408, query id 51 localhost root updating
DELETE FROM t WHERE i = 1
------- TRX HAS BEEN WAITING 23 SEC FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 4 page no 4 n bits 72 index GEN_CLUST_INDEX of table `test`.`t`
trx id 7747 lock_mode X waiting
Record lock, heap no 3 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
0: len 6; hex 000000000202; asc ;;
1: len 6; hex 000000001e41; asc A;;
2: len 7; hex 820000008b0110; asc ;;
3: len 4; hex 80000001; asc ;;
------------------
TABLE LOCK table `test`.`t` trx id 7747 lock mode IX
RECORD LOCKS space id 4 page no 4 n bits 72 index GEN_CLUST_INDEX of table `test`.`t`
trx id 7747 lock_mode X waiting
Record lock, heap no 3 PHYSICAL RECORD: n_fields 4; compact format; info bits 0
0: len 6; hex 000000000202; asc ;;
1: len 6; hex 000000001e41; asc A;;
2: len 7; hex 820000008b0110; asc ;;
3: len 4; hex 80000001; asc ;;
--------
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 (read thread)
I/O thread 4 state: waiting for i/o request (read thread)
I/O thread 5 state: waiting for i/o request (read thread)
I/O thread 6 state: waiting for i/o request (write thread)
I/O thread 7 state: waiting for i/o request (write thread)
I/O thread 8 state: waiting for i/o request (write thread)
I/O thread 9 state: waiting for i/o request (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
833 OS file reads, 605 OS file writes, 208 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 553253, node heap has 0 buffer(s)
Hash table size 553253, node heap has 1 buffer(s)
Hash table size 553253, node heap has 3 buffer(s)
Hash table size 553253, node heap has 0 buffer(s)
Hash table size 553253, node heap has 0 buffer(s)
Hash table size 553253, node heap has 0 buffer(s)
Hash table size 553253, node heap has 0 buffer(s)
Hash table size 553253, node heap has 0 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 19643450
Log buffer assigned up to 19643450
Log buffer completed up to 19643450
Log written up to 19643450
Log flushed up to 19643450
Added dirty pages up to 19643450
Pages flushed up to 19643450
Last checkpoint at 19643450
129 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 2198863872
Dictionary memory allocated 409606
Buffer pool size 131072
Free buffers 130095
Database pages 973
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 810, created 163, written 404
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: 973, 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 65536
Free buffers 65043
Database pages 491
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 411, created 80, written 210
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: 491, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 1
Buffer pool size 65536
Free buffers 65052
Database pages 482
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 399, created 83, written 194
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: 482, 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=5772, Main thread ID=140286437054208 , state=sleeping
Number of rows inserted 57, updated 354, deleted 4, read 4421
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================如需標準監控器回報之每個度量的描述，請參閱 度量 章節，位於 Oracle Enterprise Manager for MySQL Database 使用者指南 中。
狀態此區段顯示時間戳記、監控器名稱，以及每秒平均值所根據的秒數。秒數是目前時間與上次列印
InnoDB監控器輸出之間經過的時間。背景執行緒srv_master_thread行顯示主要背景執行緒所完成的工作。號誌此區段回報正在等待號誌的執行緒，以及執行緒需要對互斥鎖或讀寫鎖號誌進行旋轉或等待的次數統計資訊。大量執行緒等待號誌可能是磁碟 I/O 的結果，或是
InnoDB內部的爭用問題。InnoDB爭用可能是由於查詢的並行性過高或作業系統執行緒排程中的問題所致。將innodb_thread_concurrency系統變數設定為小於預設值的值，可能在這種情況下有所幫助。每等待旋轉次數行顯示每個 OS 互斥鎖等待的旋轉鎖輪次數。互斥鎖度量由
SHOW ENGINE INNODB MUTEX回報。最新的外鍵錯誤此區段提供有關最近的外鍵限制錯誤的資訊。如果沒有發生此類錯誤，則不會顯示此區段。內容包括失敗的陳述式，以及有關失敗限制以及參考和參考資料表的資訊。
偵測到的最新死結本節提供關於最近一次死鎖的資訊。如果沒有發生死鎖，則不會顯示此節。內容會顯示哪些交易參與其中、每個交易嘗試執行的語句、它們擁有和需要的鎖，以及
InnoDB決定回滾哪個交易以打破死鎖。本節報告的鎖定模式在第 17.7.1 節「InnoDB 鎖定」中有解釋。交易如果本節報告鎖等待，您的應用程式可能存在鎖爭用。此輸出也有助於追蹤交易死鎖的原因。
檔案 I/O本節提供關於
InnoDB用於執行各種 I/O 類型的執行緒資訊。其中最先幾個專用於一般的InnoDB處理。內容也會顯示待處理 I/O 操作的資訊以及 I/O 效能統計資料。這些執行緒的數量由
innodb_read_io_threads和innodb_write_io_threads參數控制。請參閱第 17.14 節「InnoDB 啟動選項和系統變數」。插入緩衝區和自適應雜湊索引本節顯示
InnoDB插入緩衝區（也稱為變更緩衝區）和自適應雜湊索引的狀態。相關資訊，請參閱第 17.5.2 節「變更緩衝區」和第 17.5.3 節「自適應雜湊索引」。
記錄本節顯示關於
InnoDB記錄的資訊。內容包括目前的記錄序號、記錄刷新到磁碟的進度以及InnoDB上次執行檢查點的位置。（請參閱第 17.11.3 節「InnoDB 檢查點」。）本節還會顯示關於待處理寫入和寫入效能統計資料的資訊。緩衝池和記憶體本節提供關於讀取和寫入頁面的統計資料。您可以根據這些數字計算出您的查詢目前正在執行多少資料檔案 I/O 操作。
關於緩衝池統計資料的描述，請參閱使用 InnoDB 標準監視器監視緩衝池。關於緩衝池操作的更多資訊，請參閱第 17.5.1 節「緩衝池」。
列操作本節顯示主執行緒正在做什麼，包括每種類型列操作的數量和效能速率。