Ранее в этом году я переместил сайт с небольшим трафиком, ориентированный на данные, с общего хостинга на CentOs CloudVM. Производительность была вполне приемлемой в течение 7+ месяцев - теперь ~ 10% запросов в день занимают более 5 секунд, многие из них занимают значительно больше времени.
За эти месяцы было добавлено больше данных, но ничего не изменилось в базе кода. Тем не менее, спектакль уже сошел с обрыва. Я попытался перезапустить экземпляр, настроить my.cnf, mysqltuner и т. Д., Но без каких-либо улучшений ...
Возможно, эта проблема слишком специфична для конкретного экземпляра, но если бы кто-нибудь мог предложить несколько указаний о том, где искать возможные причины такого резкого отставания в производительности, это было бы очень полезно
UPDATE
Если посмотреть на процессы top на рабочем сервере и, как правило, MySQLD работает с незначительным процентом загрузки ЦП, но часто возвращается к 100% +, прежде чем вернуться обратно.
После просмотра медленных запросов все они используют LIKE "% query text%". Однако некоторые из них работают очень быстро, другие могут занимать более 20 секунд для почти идентичных запросов.
Указанное увеличение данных происходит в области дополнительных ~ 30 тыс. Строк, добавленных к существующим ~ 340 тыс.
.
Я единственный разработчик, работающий над базой кода, и в аспекте запроса данных приложения не было внесено никаких изменений. Однако некоторые изменения в среде были сделаны сравнительно недавно, что привело к некоторой нестабильности в течение определенного периода (попытка обновить cli-версию PHP с 5.4 до 7.x). С тех пор нестабильность была устранена путем обновления всех пакетов и перезаписи плохо настроенных пакетов в настройке Apache.
Облачный экземпляр имеет 2 ГБ оперативной памяти как для веб-сервера, так и для сервера БД.
my.cnf - https://pastebin.com/DW4gpJFG
[mysqld]
bind-address = ::ffff:127.0.0.1
local-infile=0
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Added 07 Nov 2018
# https://support.plesk.com/hc/en-us/articles/213401729-Slow-performance-of-the-MySQL-on-Plesk-server
innodb_buffer_pool_size=756M
query_cache_size=64M
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
slow_query_log = 1
log-slow-queries = /var/log/mariadb/mariadb-slow.log
long_query_time = 5s
#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
MySQLTuner - https://pastebin.com/rwu61PMg
>> MySQLTuner 1.7.5 - Major Hayden <major@mhtx.net>
>> Bug reports, feature requests, and downloads at http://mysqltuner.com/
>> Run with '--help' for additional options and output filtering
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.5.60-MariaDB
[OK] Operating on 64-bit architecture
-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: /var/log/mariadb/mariadb.log(45K)
[OK] Log file /var/log/mariadb/mariadb.log exists
[OK] Log file /var/log/mariadb/mariadb.log is readable.
[OK] Log file /var/log/mariadb/mariadb.log is not empty
[OK] Log file /var/log/mariadb/mariadb.log is smaller than 32 Mb
[!!] /var/log/mariadb/mariadb.log contains 1 warning(s).
[!!] /var/log/mariadb/mariadb.log contains 16 error(s).
[--] 31 start(s) detected in /var/log/mariadb/mariadb.log
[--] 1) 181116 0:49:26 [Note] /usr/libexec/mysqld: ready for connections.
[--] 2) 181109 8:28:59 [Note] /usr/libexec/mysqld: ready for connections.
[--] 3) 181109 8:00:12 [Note] /usr/libexec/mysqld: ready for connections.
[--] 4) 181106 23:47:13 [Note] /usr/libexec/mysqld: ready for connections.
[--] 5) 181106 1:22:22 [Note] /usr/libexec/mysqld: ready for connections.
[--] 6) 181029 11:05:08 [Note] /usr/libexec/mysqld: ready for connections.
[--] 7) 181009 9:49:46 [Note] /usr/libexec/mysqld: ready for connections.
[--] 8) 180929 22:48:02 [Note] /usr/libexec/mysqld: ready for connections.
[--] 9) 180827 3:40:02 [Note] /usr/libexec/mysqld: ready for connections.
[--] 10) 180723 23:24:44 [Note] /usr/libexec/mysqld: ready for connections.
[--] 31 shutdown(s) detected in /var/log/mariadb/mariadb.log
[--] 1) 181116 0:48:02 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 2) 181109 8:28:57 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 3) 181109 8:00:09 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 4) 181106 23:47:09 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 5) 181106 1:21:09 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 6) 181029 11:04:05 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 7) 181009 9:48:37 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 8) 180929 22:46:58 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 9) 180827 3:40:00 [Note] /usr/libexec/mysqld: Shutdown complete
[--] 10) 180723 23:23:45 [Note] /usr/libexec/mysqld: Shutdown complete
-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +Aria +BLACKHOLE +CSV +FEDERATED +InnoDB +MEMORY +MRG_MYISAM +MyISAM +PERFORMANCE_SCHEMA
[--] Data in MyISAM tables: 836M (Tables: 100)
[--] Data in InnoDB tables: 28M (Tables: 356)
[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 is no basic password file list!
-------- CVE Security Recommendations --------------------------------------------------------------
[--] Skipped due to --cvefile option undefined
-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 3d 13h 42m 42s (528K q [1.714 qps], 143K conn, TX: 3G, RX: 67M)
[--] Reads / Writes: 97% / 3%
[--] Binary logging is disabled
[--] Physical Memory : 2.0G
[--] Max MySQL memory : 1.6G
[--] Other process memory: 400.6M
[--] Total buffers: 1.2G global + 2.8M per thread (151 max threads)
[--] P_S Max memory usage: 0B
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 1.2G (61.38% of installed RAM)
[OK] Maximum possible memory usage: 1.6G (81.28% of installed RAM)
[!!] Overall possible memory usage with other process exceeded memory
[OK] Slow queries: 0% (268/528K)
[OK] Highest usage of available connections: 5% (8/151)
[OK] Aborted connections: 0.00% (1/143266)
[!!] 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: 46.5% (202K cached / 436K selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 3% (57 temp sorts / 1K sorts)
[OK] No joins without indexes
[!!] Temporary tables created on disk: 70% (12K on disk / 17K total)
[OK] Thread cache hit rate: 99% (50 created / 143K connections)
[!!] Table cache hit rate: 9% (400 open / 4K opened)
[OK] Open file limit used: 21% (224/1K)
[OK] Table locks acquired immediately: 99% (63K immediate / 63K locks)
-------- Performance schema ------------------------------------------------------------------------
[--] Performance schema is disabled.
[--] Memory used by P_S: 0B
[--] Sys schema isn't installed.
-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is enabled.
[--] Thread Pool Size: 2 thread(s).
[--] Using default value is good enough for your version (5.5.60-MariaDB)
-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 75.7% (25M used / 33M cache)
[OK] Key buffer size / total MyISAM indexes: 32.0M/238.8M
[OK] Read Key buffer hit rate: 100.0% (1B cached / 79K reads)
[OK] Write Key buffer hit rate: 100.0% (18K cached / 18K writes)
-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[!!] InnoDB File per table is not activated
[OK] InnoDB buffer pool / data size: 756.0M/28.3M
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (1.32275132275132 %): 5.0M * 2/756.0M should be equal 25%
[OK] InnoDB buffer pool instances: 1
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version
[OK] InnoDB Read buffer efficiency: 99.91% (2333138 hits/ 2335267 total)
[!!] InnoDB Write Log efficiency: 2.25% (33 hits/ 1469 total)
[OK] InnoDB log waits: 0.00% (0 waits / 1436 writes)
-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is enabled.
[OK] Aria pagecache size / total Aria indexes: 128.0M/1B
[OK] Aria pagecache hit rate: 99.6% (96K cached / 359 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:
Control warning line(s) into /var/log/mariadb/mariadb.log file
Control error line(s) into /var/log/mariadb/mariadb.log file
Dedicate this server to your database for highest performance.
Enable the slow query log to troubleshoot bad queries
Configure your accounts with ip or subnets only, then update your configuration with skip-name-resolve=1
When making adjustments, make tmp_table_size/max_heap_table_size equal
Reduce your SELECT DISTINCT queries which have no LIMIT clause
Increase table_open_cache gradually to avoid file descriptor limits
Read this before increasing table_open_cache over 64: (bit.ly removed)
Beware that open_files_limit (1024) variable
should be greater than table_open_cache (400)
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: (bit.ly removed)
Variables to adjust:
query_cache_size (=0)
query_cache_type (=0)
tmp_table_size (> 16M)
max_heap_table_size (> 16M)
table_open_cache (> 400)
innodb_file_per_table=ON
innodb_log_file_size should be (=94M) if possible, so InnoDB total log files size equals to 25% of buffer pool size.
ПОКАЗАТЬ ГЛОБАЛЬНЫЙ СТАТУС;
https://pastebin.com/U9gkg6fK
ПОКАЗАТЬ ГЛОБАЛЬНЫЕ ПЕРЕМЕННЫЕ
https://pastebin.com/3n7NeEqa