mysql> show engine innodb status \G
*************************** 1. row ***************************
Type: InnoDB
Name:
Status:
=====================================
2015-04-17 10:37:02 7f1fc1fe9700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 14 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 0 srv_active, 0 srv_shutdown, 562 srv_idle
srv_master_thread log flush and writes: 562
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 2
OS WAIT ARRAY INFO: signal count 2
Mutex spin waits 0, rounds 0, OS waits 0
RW-shared spins 2, rounds 60, OS waits 2
RW-excl spins 0, rounds 0, OS waits 0
Spin rounds per wait: 0.00 mutex, 30.00 RW-shared, 0.00 RW-excl
------------
TRANSACTIONS
------------
Trx id counter 3842
Purge done for trx‘s n:o < 2856 undo n:o < 0 state: running but idle
History list length 6
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 2, OS thread handle 0x7f1fc1fe9700, query id 5 localhost root init
show engine innodb status
--------
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, 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
318 OS file reads, 5 OS file writes, 5 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 276671, node heap has 0 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
LOG
---
Log sequence number 1649686
Log flushed up to 1649686
Pages flushed up to 1649686
Last checkpoint at 1649686
0 pending log writes, 0 pending chkp writes
8 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 50138
Buffer pool size 8191
Free buffers 8025
Database pages 166
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 166, created 0, written 1
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: 166, 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
Main thread process no. 27472, id 139774264338176, state: sleeping
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
----------------------------
END OF INNODB MONITOR OUTPUT
============================
1 row in set (0.00 sec)
mysql>
参数详解:
第一段:
*************************** 1. row ***************************
Type: InnoDB --存储引擎
Name:
Status:
=====================================
2015-04-17 10:37:02 7f1fc1fe9700 INNODB MONITOR OUTPUT --监控信息输出的时间
=====================================
Per second averages calculated from the last 14 seconds
-----------------
第二段:
BACKGROUND THREAD
-----------------
srv_master_thread loops: 0 srv_active, 0 srv_shutdown, 562 srv_idle
srv_master_thread log flush and writes: 562
----------
第三段:
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 2
OS WAIT ARRAY INFO: signal count 2
Mutex spin waits 0, rounds 0, OS waits 0
RW-shared spins 2, rounds 60, OS waits 2
RW-excl spins 0, rounds 0, OS waits 0
Spin rounds per wait: 0.00 mutex, 30.00 RW-shared, 0.00 RW-excl
------------
第四段:
TRANSACTIONS
------------
Trx id counter 3842
Purge done for trx‘s n:o < 2856 undo n:o < 0 state: running but idle
History list length 6 --记录undo日志的数量
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 2, OS thread handle 0x7f1fc1fe9700, query id 5 localhost root init
show engine innodb status
--------
第五段:
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, 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
318 OS file reads, 5 OS file writes, 5 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 0.00 writes/s, 0.00 fsyncs/s
-------------------------------------
buffer thread:插入缓冲线程
log thread:日志线程
read thread:读线程
write thread:写线程
第六段:
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 276671, node heap has 0 buffer(s)
0.00 hash searches/s, 0.00 non-hash searches/s
---
seg size 2:INSERT BUFFER的大小,2X16KB
ree list len 0:空闲列表的长度
Ibuf: size 1:合并记录页的数量
insert 0:INSERT BUFFER
delete mark 0:DELETE BUFFER
delete 0:PURGE BUFFER
discarded operations:Change Buffer发生merge时表已经被删除,无需再将记录合并到辅助索引中了
第七段:
LOG
---
Log sequence number 1649686 --当前的LSN号
Log flushed up to 1649686 --刷新后的LSN号
Pages flushed up to 1649686 --刷新和事物提交后的LSN号
Last checkpoint at 1649686 --写入到磁盘后的LSN号
0 pending log writes, 0 pending chkp writes
8 log i/o‘s done, 0.00 log i/o‘s/second
----------------------
第八段:
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 137363456; in additional pool allocated 0
Dictionary memory allocated 50138
Buffer pool size 8191 --缓冲池的大小
Free buffers 8025 --剩余大小
Database pages 166 --数据库页
Old database pages 0 --旧数据库页
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 166, created 0, written 1
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: 166, unzip_LRU len: 0 --LRU(缓冲池最近最少使用),一共有166个页,unzip列表中有0个页
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
--------------
第九段:
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
Main thread process no. 27472, id 139774264338176, state: sleeping
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
----------------------------
END OF INNODB MONITOR OUTPUT
============================
本文出自 “一起走过的日子” 博客，请务必保留此出处http://tongcheng.blog.51cto.com/6214144/1633777
原文：http://tongcheng.blog.51cto.com/6214144/1633777