SHOW ENGINE INNODB STATUS is a specific form of the SHOW ENGINE statement that displays the InnoDB Monitor output, which is extensive InnoDB information which can be useful in diagnosing problems.
The following sections are displayed
Spin rounds per wait shows the number of spinlock rounds per OS wait for a mutex. If the innodb_status_output_locks system variable is set to 1, extended lock information will be displayed.
Example output:
===================================== 2019-09-06 12:44:13 0x7f93cc236700 INNODB MONITOR OUTPUT ===================================== Per second averages calculated from the last 4 seconds ----------------- BACKGROUND THREAD ----------------- srv_master_thread loops: 2 srv_active, 0 srv_shutdown, 83698 srv_idle srv_master_thread log flush and writes: 83682 ---------- SEMAPHORES ---------- OS WAIT ARRAY INFO: reservation count 15 OS WAIT ARRAY INFO: signal count 8 RW-shared spins 0, rounds 20, OS waits 7 RW-excl spins 0, rounds 0, OS waits 0 RW-sx spins 0, rounds 0, OS waits 0 Spin rounds per wait: 20.00 RW-shared, 0.00 RW-excl, 0.00 RW-sx ------------ TRANSACTIONS ------------ Trx id counter 236 Purge done for trx's n:o < 236 undo n:o < 0 state: running History list length 22 LIST OF TRANSACTIONS FOR EACH SESSION: ---TRANSACTION 421747401994584, not started 0 lock struct(s), heap size 1136, 0 row lock(s) ---TRANSACTION 421747401990328, 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: 0 286 OS file reads, 171 OS file writes, 22 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 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) Hash table size 34679, node heap has 0 buffer(s) 0.00 hash searches/s, 0.00 non-hash searches/s --- LOG --- Log sequence number 445926 Log flushed up to 445926 Pages flushed up to 445926 Last checkpoint at 445917 0 pending log flushes, 0 pending chkp writes 18 log i/o's done, 0.00 log i/o's/second ---------------------- BUFFER POOL AND MEMORY ---------------------- Total large memory allocated 167772160 Dictionary memory allocated 50768 Buffer pool size 8012 Free buffers 7611 Database pages 401 Old database pages 0 Modified db pages 0 Percent of dirty pages(LRU & free pages): 0.000 Max dirty pages percent: 75.000 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 264, created 137, written 156 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: 401, 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=4267, Main thread ID=140272021272320, state: sleeping Number of rows inserted 1, updated 0, deleted 0, read 1 0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s Number of system 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 ============================
© 2019 MariaDB
Licensed under the Creative Commons Attribution 3.0 Unported License and the GNU Free Documentation License.
https://mariadb.com/kb/en/show-engine-innodb-status/