Just recently the application that I maintain started crashing, mysql's CPU usage is 100%... or more :)
The application itself is quite old and has a lot of slow queries but before blaming it I want to check if it's not the mysql issue. I hate to ask but could someone take a look at SHOW ENGINE INNODB STATUS and tell me if there is anything suspicious in there?.
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2022-09-06 09:41:55 0x7fc0d07b6700 INNODB MONITOR OUTPUT
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Per second averages calculated from the last 19 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 331407 srv_active, 0 srv_shutdown, 746026 srv_idle
srv_master_thread log flush and writes: 1077433
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SEMAPHORES
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OS WAIT ARRAY INFO: reservation count 10587175
OS WAIT ARRAY INFO: signal count 16395655
RW-shared spins 0, rounds 53351140, OS waits 6923021
RW-excl spins 0, rounds 53028151, OS waits 518758
RW-sx spins 2458, rounds 50803, OS waits 1261
Spin rounds per wait: 53351140.00 RW-shared, 53028151.00 RW-excl, 20.67 RW-sx
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LATEST FOREIGN KEY ERROR
------------------------
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TRANSACTIONS
------------
Trx id counter 51455398
Purge done for trx's n:o < 51455398 undo n:o < 0 state: running but idle
History list length 41
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 421941565186184, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565188024, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565189864, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565183424, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565187104, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565182504, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565185264, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565180664, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565181584, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565184344, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
---TRANSACTION 421941565179744, not started
0 lock struct(s), heap size 1136, 0 row lock(s)
--------
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] , 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
3407791191 OS file reads, 23186343 OS file writes, 2496201 OS fsyncs
1 pending preads, 0 pending pwrites
3625.23 reads/s, 16384 avg bytes/read, 124.73 writes/s, 14.53 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 3093, seg size 3095, 718207 merges
merged operations:
insert 773740, delete mark 82990, delete 494
discarded operations:
insert 0, delete mark 0, delete 0
Hash table size 34679, node heap has 1 buffer(s)
Hash table size 34679, node heap has 12 buffer(s)
Hash table size 34679, node heap has 73 buffer(s)
Hash table size 34679, node heap has 50 buffer(s)
Hash table size 34679, node heap has 8 buffer(s)
Hash table size 34679, node heap has 45 buffer(s)
Hash table size 34679, node heap has 2 buffer(s)
Hash table size 34679, node heap has 18 buffer(s)
32794.22 hash searches/s, 21657.81 non-hash searches/s
---
LOG
---
Log sequence number 94588304242
Log flushed up to 94588304242
Pages flushed up to 94588300431
Last checkpoint at 94588296730
0 pending log flushes, 0 pending chkp writes
1221882 log i/o's done, 3.05 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total large memory allocated 137428992
Dictionary memory allocated 3122549
Buffer pool size 8192
Free buffers 634
Database pages 7349
Old database pages 2732
Modified db pages 191
Pending reads 1
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 105805584, not young 27891291271
0.00 youngs/s, 0.00 non-youngs/s
Pages read 3407821728, created 13603254, written 21494430
0.00 reads/s, 0.00 creates/s, 0.00 writes/s
Buffer pool hit rate 982 / 1000, young-making rate 0 / 1000 not 374 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 7349, unzip_LRU len: 0
I/O sum[276774]:cur[88], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
0 queries inside InnoDB, 0 queries in queue
1 read views open inside InnoDB
Process ID=1, Main thread ID=140466150430464, state: sleeping
Number of rows inserted 428234279, updated 1035424, deleted 45779, read 70493463554
2454.98 inserts/s, 1.42 updates/s, 0.05 deletes/s, 66260.57 reads/s
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END OF INNODB MONITOR OUTPUT
============================
