查看使用的数据库引擎 show variables like '%storage_engine%';
显示的使用的是InnoDB
查看引擎状态 show engine innodb status
=====================================
2020-06-09 11:48:38 7fd22fb2c700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 0 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 99893 srv_active, 0 srv_shutdown, 1024866 srv_idle
srv_master_thread log flush and writes: 1124757
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 366976
OS WAIT ARRAY INFO: signal count 349471
Mutex spin waits 1394525, rounds 2643577, OS waits 41106
RW-shared spins 512553, rounds 12732271, OS waits 319778
RW-excl spins 4340, rounds 105641, OS waits 2110
Spin rounds per wait: 1.90 mutex, 24.84 RW-shared, 24.34 RW-excl
------------
TRANSACTIONS
------------
Trx id counter 464642414
Purge done for trx's n:o < 464631391 undo n:o < 0 state: running but idle
History list length 2461
LIST OF TRANSACTIONS FOR EACH SESSION:
MySQL thread id 143417, OS thread handle 0x7fd22e452700, query id 84732229 127.0.0.1 root cleaning up
show engine innodb status
#select * from information_schema.INNODB_TRX ;
#show variables like '%storage_engine%'
---TRANSACTION 464587469, not started
MySQL thread id 142688, OS thread handle 0x7fd425e75700, query id 84677131 127.0.0.1 root cleaning up
---TRANSACTION 464597349, not started
MySQL thread id 142687, OS thread handle 0x7fd22ebaf700, query id 84687094 127.0.0.1 root cleaning up
---TRANSACTION 464607470, not started
MySQL thread id 142686, OS thread handle 0x7fd22e71d700, query id 84697319 127.0.0.1 root cleaning up
---TRANSACTION 464607471, not started
MySQL thread id 142685, OS thread handle 0x7fd4240c0700, query id 84697320 127.0.0.1 root cleaning up
---TRANSACTION 464254382, not started
MySQL thread id 142684, OS thread handle 0x7fd22d69c700, query id 84336132 127.0.0.1 root cleaning up
---TRANSACTION 464608723, not started
MySQL thread id 142682, OS thread handle 0x7fd22ea6a700, query id 84698590 127.0.0.1 root cleaning up
---TRANSACTION 464642306, not started
--------
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, 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
174404 OS file reads, 1899052 OS file writes, 1503321 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 2751, seg size 2753, 1233 merges
merged operations:
insert 1920, delete mark 605, delete 31
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 276671, node heap has 425 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 381451654439
Log flushed up to 381451654439
Pages flushed up to 381451654439
Last checkpoint at 381451654439
0 pending log writes, 0 pending chkp writes
842557 log i/o's done, 0.00 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 137363456; in additional pool allocated 0
Dictionary memory allocated 1530044
Buffer pool size 8191
Free buffers 1024
Database pages 6742
Old database pages 2468
Modified db pages 0
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 294210, not young 5207682
0.00 youngs/s, 0.00 non-youngs/s
Pages read 514664, created 5569, written 857904
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: 6742, unzip_LRU len: 0
I/O sum[14]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Main thread process no. 5866, id 140549256718080, state: sleeping
Number of rows inserted 258137, updated 519709, deleted 218944, read 2068368590
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================
输出如下，以后一个个解释