show engine innodb status

mysql> show engine innodb status \G

*************************** 1. row ***************************

  Type: InnoDB

  Name:

Status:

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110412 20:45:39 INNODB MONITOR OUTPUT

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Per second averages calculated from the last 33 seconds 下面显示的信息是33秒之前的数据库状态

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BACKGROUND THREAD

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srv_master_thread loops: 1 1_second, 1 sleeps, 0 10_second, 2 background, 2 flush

srv_master_thread log flush and writes: 1

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SEMAPHORES

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OS WAIT ARRAY INFO: reservation count 4, signal count 4

Mutex spin waits 1, rounds 30, OS waits 1

RW-shared spins 3, rounds 90, OS waits 3

RW-excl spins 0, rounds 0, OS waits 0

Spin rounds per wait: 30.00 mutex, 30.00 RW-shared, 0.00 RW-excl

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TRANSACTIONS

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Trx id counter D00

Purge done for trx's n:o < 0 undo n:o < 0

History list length 0

LIST OF TRANSACTIONS FOR EACH SESSION:

---TRANSACTION 0, not started, process no 21250, OS thread id 1232701760

MySQL thread id 1, query id 6 localhost root

show engine innodb status

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FILE I/O 下面显示了4种IO进程，read和write

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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, 0] , aio writes: 0 [0, 0, 0, 0] ,

 ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0

Pending flushes (fsync) log: 0; buffer pool: 0

26 OS file reads, 147 OS file writes, 10 OS fsyncs

0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s

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INSERT BUFFER AND ADAPTIVE HASH INDEX

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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 276671, node heap has 0 buffer(s)

0.00 hash searches/s, 0.00 non-hash searches/s

---

LOG

---

Log sequence number 1588801

Log flushed up to   1588801

Last checkpoint at  1588801

0 pending log writes, 0 pending chkp writes

10 log i/o's done, 0.00 log i/o's/second

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BUFFER POOL AND MEMORY 这下面的信息可以看到InnoDB存储引擎缓冲池的使用情况

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Total memory allocated 137363456; in additional pool allocated 0

Dictionary memory allocated 33650

Buffer pool size   8191 表明一共有多少个缓冲帧（buffer frame），每个缓冲帧为16K，缓冲池大小：8191*16/1024≈127M

Free buffers       8048 表示当前空闲的缓冲帧

Database pages     143 表示已经使用的缓冲帧

Old database pages 0

Modified db pages  0 表示脏页的数量

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 15, created 128, written 131

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

LRU len: 143, unzip_LRU len: 0

I/O sum[0]:cur[0], unzip sum[0]:cur[0]

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ROW OPERATIONS

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0 queries inside InnoDB, 0 queries in queue

1 read views open inside InnoDB

Main thread process no. 21250, id 1200699712, state: waiting for server activity

Number of rows inserted 0, updated 0, deleted 0, read 0

0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s

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END OF INNODB MONITOR OUTPUT

============================



1 row in set (0.55 sec)



查看innodb版本，read和write线程数



mysql> show variables like 'innodb_version' \G

*************************** 1. row ***************************

Variable_name: innodb_version

        Value: 1.1.6

1 row in set (0.00 sec)



mysql> show variables like 'innodb_%io_threads