Wir haben ernsthafte Probleme mit einem unserer Produktionsserver. Das fragliche Setup ist ein CentOS 7 64-Bit-Server mit 16 GB RAM und 250 GB SSD (daher sollte das Setup sehr schnell sein). Der LEMP-Stack ist mit MariaDB 10.1.29 konfiguriert. Auf diesem Server werden ungefähr 20 Anwendungen ausgeführt, von denen jede ihre eigene Datenbank verwendet.
Vor einigen Wochen haben wir in unserem Statusmonitor (Pingen jeder Anwendung in 5-Minuten-Intervallen und Messen der Reaktionszeit) festgestellt, dass 3 Anwendungen von Zeit zu Zeit sehr langsam ausgeführt werden. (Reaktionszeiten von 2 bis 10 Sekunden, während der Durchschnitt bei ~ 0,1 Sekunden liegt). Das langsame Protokoll von MariaDB ist voll von langsamen Abfragen (die meisten davon sind das einfache Einfügen, Auswählen und Aktualisieren von Abfragen für den Sitzungsspeicher), die manchmal bis zu 15 Sekunden dauern, jedoch nur von diesen drei Anwendungen.
Was diese drei Anwendungen im Vergleich zu den anderen gemeinsam haben, verwenden sie alle InnoDBanstelle von MyISAM. Für das weitere Debuggen haben wir drei weitere Anwendungen von MyISAM auf InnoDB konvertiert, und diese litten ebenfalls unter denselben Verzögerungen.
Ich konnte das Profil einer langsamen Abfrage abfangen und das Problem scheint damit zu tun zu haben query end.
Das Problem ist (oder was das Debuggen erschwert), wir können keine Regelmäßigkeit feststellen und Abfragen funktionieren in 99% der Fälle schnell.
Bearbeiten, um weitere Metriken und Statistiken hinzuzufügen, auch in Kommentaren, aber um einen besseren Überblick zu erhalten
Beispiel: PROFIL Liste einfacher UPDATE-Abfragen:
213 | 0.01676252 | update `users` set `remember_token` = 'PpIxVPJE4Hkc981B6C6dT0aeCaExgjmR2GOydFqDZpU36O6z0mOsGic1DYIO' where `id` = 1
214 | 0.00950012 | update `users` set `remember_token` = 'PpIxVPJE4Hkc981B6C6dT0aeCaExgjmR2GOydFqDZpU36O6z0mOsGic1DYIO' where `id` = 1
215 | 0.00679076 | update `users` set `remember_token` = 'PpIxVPJE4Hkc981B6C6dT0aeCaExgjmR2GOydFqDZpU36O6z0mOsGic1DYIO' where `id` = 1
216 | 4.06162153 | update `users` set `remember_token` = 'PpIxVPJE4Hkc981B6C6dT0aeCaExgjmR2GOydFqDZpU36O6z0mOsGic1DYIO' where `id` = 1
217 | 0.20616296 | update `users` set `remember_token` = 'PpIxVPJE4Hkc981B6C6dT0aeCaExgjmR2GOydFqDZpU36O6z0mOsGic1DYIO' where `id` = 1Erklärung von 216:
# Time: 171211 11:32:59
# User@Host: msze[msze] @ localhost []
# Thread_id: 17956 Schema: msze QC_hit: No
# Query_time: 4.061399 Lock_time: 0.000129 Rows_sent: 0 Rows_examined: 1
# Rows_affected: 0
#
# explain: id select_type table type possible_keys key key_len ref rows r_rows filtered r_filtered Extra
# explain: 1 SIMPLE users range PRIMARY PRIMARY 4 NULL 1 1.00 100.00 100.00 Using where
#SHOW PROFILE von 216:
MariaDB [msze]> SHOW PROFILE FOR QUERY 216;
+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| starting | 0.000086 |
| checking permissions | 0.000010 |
| Opening tables | 0.000027 |
| After opening tables | 0.000013 |
| System lock | 0.000006 |
| Table lock | 0.000006 |
| init | 0.000071 |
| updating | 0.000099 |
| end | 0.000008 |
| query end | 4.061019 |
| closing tables | 0.000032 |
| Unlocking tables | 0.000022 |
| freeing items | 0.000012 |
| updating status | 0.000028 |
| logging slow query | 0.000155 |
| cleaning up | 0.000026 |
+----------------------+----------+SHOW ENGINE INNODB STATUS direkt nach einer der langsamen Abfragen:
| InnoDB | |
=====================================
2017-12-13 00:13:40 7f4284d09700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 23 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 3715 srv_active, 0 srv_shutdown, 284907 srv_idle
srv_master_thread log flush and writes: 288609
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 3356
OS WAIT ARRAY INFO: signal count 3336
Mutex spin waits 7065, rounds 46684, OS waits 1287
RW-shared spins 1838, rounds 55280, OS waits 1837
RW-excl spins 35, rounds 6925, OS waits 219
Spin rounds per wait: 6.61 mutex, 30.08 RW-shared, 197.86 RW-excl
------------
TRANSACTIONS
------------
Trx id counter 17909160
Purge done for trx's n:o < 17909160 undo n:o < 0 state: running but idle
History list length 16
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 35655, OS thread handle 0x7f4284d09700, query id 1503058 localhost msze init
SHOW ENGINE INNODB STATUS
---TRANSACTION 17909158, not started flushing log, thread declared inside InnoDB 4999
mysql tables in use 1, locked 1
MySQL thread id 35641, OS thread handle 0x7f4284ccc700, query id 1503057 localhost msze query end
update `users` set `remember_token` = 'PpIxVPJE4Hkc981B6C6dT0aeCaExgjmR2GOydFqDZpU36O6z0mOsGic1DYIO' where `id` = 1
---TRANSACTION 17851651, not started
MySQL thread id 1, OS thread handle 0x7f428971d700, query id 0 Waiting for requests
--------
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 (read thread)
I/O thread 7 state: waiting for completed aio requests (read thread)
I/O thread 8 state: waiting for completed aio requests (read thread)
I/O thread 9 state: waiting for completed aio requests (read thread)
I/O thread 10 state: waiting for completed aio requests (write thread)
I/O thread 11 state: waiting for completed aio requests (write thread)
I/O thread 12 state: waiting for completed aio requests (write thread)
I/O thread 13 state: waiting for completed aio requests (write thread)
I/O thread 14 state: waiting for completed aio requests (write thread)
I/O thread 15 state: waiting for completed aio requests (write thread)
I/O thread 16 state: waiting for completed aio requests (write thread)
I/O thread 17 state: waiting for completed aio requests (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0, 0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0, 0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 1; buffer pool: 0
9331 OS file reads, 32092 OS file writes, 12460 OS fsyncs
0.00 reads/s, 0 avg bytes/read, 1.65 writes/s, 1.52 fsyncs/s
-------------------------------------
INSERT BUFFER AND ADAPTIVE HASH INDEX
-------------------------------------
Ibuf: size 1, free list len 0, seg size 2, 17 merges
merged operations:
insert 13, delete mark 6, delete 0
discarded operations:
insert 0, delete mark 0, delete 0
60.00 hash searches/s, 6.48 non-hash searches/s
---
LOG
---
Log sequence number 885763031
Log flushed up to 885762812
Pages flushed up to 885752827
Last checkpoint at 885752827
Max checkpoint age 650641675
Checkpoint age target 630309123
Modified age 10204
Checkpoint age 10204
1 pending log writes, 0 pending chkp writes
7104 log i/o's done, 1.43 log i/o's/second
----------------------
BUFFER POOL AND MEMORY
----------------------
Total memory allocated 2249195520; in additional pool allocated 0
Total memory allocated by read views 232
Internal hash tables (constant factor + variable factor)
Adaptive hash index 36929728 (35401816 + 1527912)
Page hash 1107208 (buffer pool 0 only)
Dictionary cache 21776008 (8851984 + 12924024)
File system 1924912 (812272 + 1112640)
Lock system 5314496 (5313416 + 1080)
Recovery system 0 (0 + 0)
Dictionary memory allocated 12924024
Buffer pool size 131070
Buffer pool size, bytes 2147450880
Free buffers 122651
Database pages 8326
Old database pages 3102
Modified db pages 135
Percent of dirty pages(LRU & free pages): 0.103
Max dirty pages percent: 90.000
Pending reads 0
Pending writes: LRU 0, flush list 3, single page 0
Pages made young 1, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 8093, created 233, written 23247
0.00 reads/s, 0.00 creates/s, 0.17 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 8326, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
----------------------
INDIVIDUAL BUFFER POOL INFO
----------------------
---BUFFER POOL 0
Buffer pool size 65535
Buffer pool size, bytes 1073725440
Free buffers 61371
Database pages 4115
Old database pages 1528
Modified db pages 61
Percent of dirty pages(LRU & free pages): 0.093
Max dirty pages percent: 90.000
Pending reads 0
Pending writes: LRU 0, flush list 3, single page 0
Pages made young 0, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 3996, created 119, written 11904
0.00 reads/s, 0.00 creates/s, 0.09 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 4115, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
---BUFFER POOL 1
Buffer pool size 65535
Buffer pool size, bytes 1073725440
Free buffers 61280
Database pages 4211
Old database pages 1574
Modified db pages 74
Percent of dirty pages(LRU & free pages): 0.113
Max dirty pages percent: 90.000
Pending reads 0
Pending writes: LRU 0, flush list 0, single page 0
Pages made young 1, not young 0
0.00 youngs/s, 0.00 non-youngs/s
Pages read 4097, created 114, written 11343
0.00 reads/s, 0.00 creates/s, 0.09 writes/s
Buffer pool hit rate 1000 / 1000, young-making rate 0 / 1000 not 0 / 1000
Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s
LRU len: 4211, unzip_LRU len: 0
I/O sum[0]:cur[0], unzip sum[0]:cur[0]
--------------
ROW OPERATIONS
--------------
1 queries inside InnoDB, 0 queries in queue
0 read views open inside InnoDB
0 RW transactions active inside InnoDB
0 RO transactions active inside InnoDB
0 out of 1000 descriptors used
Main thread process no. 26161, id 139920697968384, state: sleeping
Number of rows inserted 1949, updated 2279, deleted 1540, read 53481986
0.00 inserts/s, 1.39 updates/s, 0.00 deletes/s, 158.34 reads/s
Number of system rows inserted 0, updated 0, deleted 0, read 8
0.00 inserts/s, 0.00 updates/s, 0.00 deletes/s, 0.00 reads/s
----------------------------
END OF INNODB MONITOR OUTPUT
============================Meine server.cnf(basierend auf MariaDB InnoDB 4GB Template):
[client]
port = 3306
socket = /var/lib/mysql/mysql.sock
[mysqld]
character-set-server = utf8
collation-server = utf8_unicode_ci
performance_schema
port = 3306
socket = /var/lib/mysql/mysql.sock
back_log = 50
bind-address = 127.0.0.1
max_connections = 100
max_connect_errors = 10
table_open_cache = 2048
max_allowed_packet = 16M
binlog_cache_size = 1M
max_heap_table_size = 64M
read_buffer_size = 2M
read_rnd_buffer_size = 16M
sort_buffer_size = 8M
join_buffer_size = 8M
thread_cache_size = 8
thread_concurrency = 8
query_cache_size = 64M
query_cache_limit = 2M
ft_min_word_len = 4
thread_stack = 240K
transaction_isolation = REPEATABLE-READ
tmp_table_size = 64M
slow_query_log = 1
slow_query_log_file = /var/log/mariadb/slow.log
log_error = /var/log/mariadb/error.log
log_slow_verbosity = query_plan,explain
long_query_time = 1
key_buffer_size = 32M
bulk_insert_buffer_size = 64M
myisam_sort_buffer_size = 128M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
myisam-recover-options
innodb_buffer_pool_size = 2G
innodb_buffer_pool_instances = 2
innodb_data_file_path = ibdata1:10M:autoextend
innodb_write_io_threads = 8
innodb_read_io_threads = 8
innodb_thread_concurrency = 16
innodb_flush_log_at_trx_commit = 1
innodb_log_buffer_size = 8M
innodb_log_file_size = 256M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120
[mysqld_safe]
open-files-limit = 8192Ausgabe von $ cat /proc/meminfo
MemTotal: 16267832 kB
MemFree: 2878892 kB
MemAvailable: 14543648 kBAusgabe von ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 63471
max locked memory (kbytes, -l) 64
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 0
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 4096
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimitedMySQLTuner-Bericht:
[OK] Operating on 64-bit architecture
-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: /var/log/mariadb/error.log(2K)
[OK] Log file /var/log/mariadb/error.log exists
[OK] Log file /var/log/mariadb/error.log is readable.
[OK] Log file /var/log/mariadb/error.log is not empty
[OK] Log file /var/log/mariadb/error.log is smaller than 32 Mb
[OK] /var/log/mariadb/error.log doesn't contain any warning.
[OK] /var/log/mariadb/error.log doesn't contain any error.
[--] 1 start(s) detected in /var/log/mariadb/error.log
[--] 1) 2017-12-09 15:36:50 139923750996224 [Note] /usr/sbin/mysqld: ready for connections.
[--] 1 shutdown(s) detected in /var/log/mariadb/error.log
[--] 1) 2017-12-09 15:36:49 140153230964480 [Note] /usr/sbin/mysqld: Shutdown complete
-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +Aria +CSV +InnoDB +MEMORY +MRG_MyISAM +MyISAM +PERFORMANCE_SCHEMA +SEQUENCE
[--] Data in MyISAM tables: 589K (Tables: 16)
[--] Data in InnoDB tables: 136M (Tables: 1093)
[OK] Total fragmented tables: 0
-------- Security Recommendations ------------------------------------------------------------------
[OK] There are no anonymous accounts for any database users
[OK] All database users have passwords assigned
[--] There are 612 basic passwords in the list.
-------- CVE Security Recommendations --------------------------------------------------------------
[OK] NO SECURITY CVE FOUND FOR YOUR VERSION
-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 3d 8h 55m 54s (1M q [3.970 qps], 35K conn, TX: 2G, RX: 544M)
[--] Reads / Writes: 99% / 1%
[--] Binary logging is disabled
[--] Physical Memory : 15.5G
[--] Max MySQL memory : 5.7G
[--] Other process memory: 2.2G
[--] Total buffers: 2.3G global + 34.2M per thread (100 max threads)
[--] P_S Max memory usage: 86M
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 2.9G (18.58% of installed RAM)
[OK] Maximum possible memory usage: 5.7G (36.90% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (195/1M)
[OK] Highest usage of available connections: 15% (15/100)
[OK] Aborted connections: 0.01% (5/35743)
[!!] name resolution is active : a reverse name resolution is made for each new connection and can reduce performance
[!!] Query cache may be disabled by default due to mutex contention.
[OK] Query cache efficiency: 48.0% (923K cached / 1M selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 11K sorts)
[!!] Joins performed without indexes: 1715
[!!] Temporary tables created on disk: 55% (14K on disk / 26K total)
[OK] Thread cache hit rate: 99% (19 created / 35K connections)
[OK] Table cache hit rate: 24% (2K open / 8K opened)
[OK] Open file limit used: 0% (136/16K)
[OK] Table locks acquired immediately: 100% (64K immediate / 64K locks)
-------- Performance schema ------------------------------------------------------------------------
[--] Memory used by P_S: 86.4M
[--] Sys schema isn't installed.
-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is enabled.
[--] Thread Pool Size: 4 thread(s).
[--] Using default value is good enough for your version (10.1.29-MariaDB)
-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 18.3% (6M used / 33M cache)
[OK] Key buffer size / total MyISAM indexes: 32.0M/233.0K
[!!] Read Key buffer hit rate: 92.3% (600 cached / 46 reads)
-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 16
[OK] InnoDB File per table is activated
[OK] InnoDB buffer pool / data size: 2.0G/136.0M
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (37.5 %): 256.0M * 3/2.0G should be equal 25%
[OK] InnoDB buffer pool instances: 2
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version
[OK] InnoDB Read buffer efficiency: 99.94% (12810512 hits/ 12818468 total)
[!!] InnoDB Write Log efficiency: 86.04% (35125 hits/ 40825 total)
[OK] InnoDB log waits: 0.00% (0 waits / 5700 writes)
-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is enabled.
[OK] Aria pagecache size / total Aria indexes: 128.0M/1B
[!!] Aria pagecache hit rate: 91.8% (144K cached / 11K reads)
-------- TokuDB Metrics ----------------------------------------------------------------------------
[--] TokuDB is disabled.
-------- XtraDB Metrics ----------------------------------------------------------------------------
[--] XtraDB is disabled.
-------- RocksDB Metrics ---------------------------------------------------------------------------
[--] RocksDB is disabled.
-------- Spider Metrics ----------------------------------------------------------------------------
[--] Spider is disabled.
-------- Connect Metrics ---------------------------------------------------------------------------
[--] Connect is disabled.
-------- Galera Metrics ----------------------------------------------------------------------------
[--] Galera is disabled.
-------- Replication Metrics -----------------------------------------------------------------------
[--] Galera Synchronous replication: NO
[--] No replication slave(s) for this server.
[--] This is a standalone server.
-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
Configure your accounts with ip or subnets only, then update your configuration with skip-name-resolve=1
Adjust your join queries to always utilize indexes
When making adjustments, make tmp_table_size/max_heap_table_size equal
Reduce your SELECT DISTINCT queries which have no LIMIT clause
Consider installing Sys schema from https://github.com/mysql/mysql-sys
Read this before changing innodb_log_file_size and/or innodb_log_files_in_group:
Variables to adjust:
query_cache_size (=0)
query_cache_type (=0)
join_buffer_size (> 8.0M, or always use indexes with joins)
tmp_table_size (> 64M)
max_heap_table_size (> 64M)
innodb_log_file_size should be (=170M) if possible, so InnoDB total log files size equals to 25% of buffer pool size.Zusätzliche Metriken von Pastebin:
key_buffer_sizeist auf134217728per mysqltuner.pl-Skript festgelegt.cat /proc/meminfozeigtMemTotal: 16267832 kB,MemFree: 2643524 kB,MemAvailable: 15089280 kBAntworten:
Ok, ich werde es versuchen, weil es eine solide Frage ist. Sie können hier sehen
Offensichtlich ist etwas los, Sie warten 7 Sekunden auf eine Semaphorsperre. Und deine Spinrunden scheinen auch hoch zu sein.
Wir wissen also, dass Sie ein böses Verriegelungsproblem haben.
Das ist meine Vermutung für Ihr Problem. Das sind die Maximalwerte . Aus den Dokumenten
Sie könnten also 16.384 Lesevorgänge in der Warteschlange und 16.384 Schreibvorgänge in der Warteschlange mit dieser Konfiguration haben, indem inno auf dem aio-Backend ausgeführt wird. Selbst wenn Sie auf einer Milliarden-Dollar-SAS sind, kann ich nicht sehen, dass dies ein produktiver Wert ist. Der Standardwert ist 4. Und mit dieser Standardeinstellung sind Sie wahrscheinlich in Ordnung. Was Sie tun, ist, Ihren Thread-Scheduler zu testen, CPU-Zeitausgleichsthreads zu verlieren und MySQL in ein Chaos von Mutex-Sperren zu treiben. Um die Sache noch schlimmer zu machen, glaube ich, dass die 7s anzeigt, dass Sie sich in der zweiten Phase eines Innodb-Wartens befinden: Das heißt, der Thread schläft tatsächlich .
Das Ändern dieser Werte wird wahrscheinlich für Sie funktionieren.
quelle
216das das gleiche ist, aber warum läuft es 4x langsamer? Ich kann Alternativen posten, die unter diesen Symptomen leiden. @EvanCarroll vielleicht InnoDB böse Sperren? Erwähnt hier und hier . Vielleichtmy.cnffunktionieren die InnoDB-Einstellungen nicht mit dem Rest meines Setups, was zu übermäßigem Spülen / Sperren führt?Beachten Sie nach der Analyse Ihrer vor 17 Stunden veröffentlichten Daten Folgendes.
Holen Sie sich ulimit Öffnen Sie Dateien nach Möglichkeit auf 65536. Der aktuelle Bericht gibt an, dass 1024 Ihr Limit für offene Dateien ist.
my.cnf Dinge, die im Abschnitt [mysqld] zu tun sind, könnten Hinzufügen / Ändern / Löschen sein
Ihr globaler Statusbericht zeigt A) innodb_buffer_pool_dump_status Dumping und B) innodb_buffer_pool_load_status Loading an. Dies scheint im Widerspruch zueinander zu stehen. Möglicherweise wird das Herunterfahren / Neustarten die Verwirrung beseitigen. Lassen Sie mich bitte wissen, ob Ihre 5-Minuten-Stände weg sind. Die Frage 75439 von dba.stackexchange.com weist darauf hin, dass nicht genügend Bereinigungsthreads die Hauptursache für Verzögerungen sind. Ihre Größe von innodb_log_buffer_size und innodb_log_file_size ist für die aktuelle Aktivität ausreichend. Wenn Sie innodb_buffer_pool_size um 1G erhöhen, werden Sie auf weitere Tabellen vorbereitet, die schließlich in innodb landen. Wenn Sie möchten, habe ich mehr auf der Wäscheliste der Dinge in my.cnf zu tun, um Ihre Operationen zu verbessern.
quelle
Nachdem wir alle verschiedenen Konfigurationen und Testszenarien ausprobiert hatten, hatten wir ein Gespräch mit dem Hosting-Unternehmen. Die Leistungseinbußen wurden tatsächlich dadurch verursacht, dass RAID-Arrays stark ausgelastet waren. Nachdem sie das RAID ausgetauscht haben, funktioniert alles wie erwartet, ohne dass langsame Abfragen erforderlich sind ...
quelle