Resolvido aumentando o buffer pool de innodb para 60% do RAM e também reconstruindo o banco de dados (export / drop / import)
Eu tenho um problema que ocasionalmente (uma ou duas vezes por semana, não necessariamente durante o horário de pico) que consultas em um determinado banco de dados (o banco de dados do maior dos meus sites) de repente parar de responder por cerca de uma hora. As consultas começam a se acumular, principalmente nos estados de "envio de dados" e "estatísticas", e, por fim, a carga sobe > 40, e todo o servidor pára.
Enquanto esse problema está acontecendo, se eu desabilitar este site, todos os outros sites e dbs no mesmo servidor serão executados normalmente.
Eu tenho a saída de "SHOW ENGINE INNODB STATUS" quando não estava respondendo, estou pensando se alguém poderia me dizer se ele mostra alguma anomalia - eu removi a seção "TRANSACTIONS" que lista todas as consultas pendentes, Eu posso adicioná-lo se isso ajudar.
5.1.70-cll MySQL Community Server, sem plugin Innodb, CentOS 5.9
Obrigado antecipadamente.
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130901 17:10:26 INNODB MONITOR OUTPUT
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Per second averages calculated from the last 50 seconds
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SEMAPHORES
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OS WAIT ARRAY INFO: reservation count 25977, signal count 14540
--Thread 140248378771776 has waited at btr/btr0cur.c line 467 for 1.00 seconds the semaphore:
S-lock on RW-latch at 0x7f8e273f8ae8 created in file buf/buf0buf.c line 550
a writer (thread id 140248378771776) has reserved it in mode exclusive
number of readers 0, waiters flag 1
Last time read locked in file btr/btr0sea.c line 794
Last time write locked in file buf/buf0buf.c line 1820
--Thread 140248434157888 has waited at btr/btr0cur.c line 467 for 3.00 seconds the semaphore:
S-lock on RW-latch at 0x7f8e272877c8 created in file buf/buf0buf.c line 550
a writer (thread id 140248434157888) has reserved it in mode exclusive
number of readers 0, waiters flag 1
Last time read locked in file btr/btr0sea.c line 794
Last time write locked in file buf/buf0buf.c line 1820
Mutex spin waits 0, rounds 550914, OS waits 8104
RW-shared spins 34629, OS waits 16634; RW-excl spins 2759, OS waits 586
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FILE I/O
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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: doing file i/o (read thread) ev set
I/O thread 3 state: waiting for i/o request (write thread)
Pending normal aio reads: 172, aio writes: 0,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
105909 OS file reads, 8365 OS file writes, 4079 OS fsyncs
1 pending preads, 1 pending pwrites
106.42 reads/s, 19475 avg bytes/read, 9.50 writes/s, 4.68 fsyncs/s
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INSERT BUFFER AND ADAPTIVE HASH INDEX
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Ibuf: size 20, free list len 70, seg size 91,
1099 inserts, 8617 merged recs, 2154 merges
Hash table size 1888559, node heap has 2598 buffer(s)
8189.64 hash searches/s, 941.80 non-hash searches/s
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LOG
---
Log sequence number 196 2706819157
Log flushed up to 196 2706818752
Last checkpoint at 196 2705105219
0 pending log writes, 0 pending chkp writes
3880 log i/o's done, 4.42 log i/o's/second
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BUFFER POOL AND MEMORY
----------------------
Total memory allocated 1061750976; in additional pool allocated 1048576
Dictionary memory allocated 1530760
Buffer pool size 58240
Free buffers 0
Database pages 55642
Modified db pages 1543
Pending reads 172
Pending writes: LRU 120, flush list 0, single page 0
Pages read 127164, created 59, written 5866
126.52 reads/s, 0.08 creates/s, 5.82 writes/s
Buffer pool hit rate 996 / 1000
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ROW OPERATIONS
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8 queries inside InnoDB, 27 queries in queue
17 read views open inside InnoDB
Main thread process no. 2504, id 140248394586432, state: sleeping
Number of rows inserted 963, updated 4397, deleted 5, read 43384960
1.56 inserts/s, 4.92 updates/s, 0.00 deletes/s, 17291.99 reads/s
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END OF INNODB MONITOR OUTPUT
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Tags mysql optimization