Usando o mysqltuner, estou um pouco preocupado com o máximo de memória que o sql parece querer conseguir ... Eu só quero ajustar o SQL para rodar melhor e entender como fazer isso sozinho.
Aqui estão meus resultados do mysqltuner;
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.7.32
[OK] Operating on 64-bit architecture
-------- Log file Recommendations ------------------------------------------------------------------
[OK] Log file /var/log/mysqld.log exists
[--] Log file: /var/log/mysqld.log(141K)
[OK] Log file /var/log/mysqld.log is readable.
[OK] Log file /var/log/mysqld.log is not empty
[OK] Log file /var/log/mysqld.log is smaller than 32 Mb
[!!] /var/log/mysqld.log contains 246 warning(s).
[!!] /var/log/mysqld.log contains 46 error(s).
[--] 16 start(s) detected in /var/log/mysqld.log
[--] 1) 2021-01-14T11:30:59.930120Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 2) 2021-01-14T11:08:52.530228Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 3) 2021-01-14T11:06:44.798420Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 4) 2021-01-14T10:58:56.636812Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 5) 2021-01-14T10:58:49.998564Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 6) 2021-01-14T10:23:15.649280Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 7) 2021-01-14T09:35:59.598495Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 8) 2021-01-14T09:35:24.591837Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 9) 2021-01-14T09:26:15.821136Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 10) 2021-01-14T08:23:56.658016Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 7 shutdown(s) detected in /var/log/mysqld.log
[--] 1) 2021-01-14T11:27:51.895559Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 2) 2021-01-14T11:08:49.145150Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 3) 2021-01-14T11:06:24.969477Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 4) 2021-01-14T10:58:53.419431Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 5) 2021-01-14T09:35:54.472640Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 6) 2021-01-08T08:38:07.365178Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 7) 2021-01-07T20:25:04.834240Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MEMORY +MRG_MYISAM +MyISAM +PERFORMANCE_SCHEMA
[--] Data in InnoDB tables: 525.3M (Tables: 446)
[OK] Total fragmented tables: 0
-------- Analysis Performance Metrics --------------------------------------------------------------
[--] innodb_stats_on_metadata: OFF
[OK] No stat updates during querying INFORMATION_SCHEMA.
-------- 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: 13m 25s (63K q [79.404 qps], 358 conn, TX: 381M, RX: 20M)
[--] Reads / Writes: 91% / 9%
[--] Binary logging is disabled
[--] Physical Memory : 2.8G
[--] Max MySQL memory : 38.0G
[--] Other process memory: 0B
[--] Total buffers: 81.0M global + 257.1M per thread (151 max threads)
[--] P_S Max memory usage: 72B
[--] Galera GCache Max memory usage: 0B
[!!] Maximum reached memory usage: 2.6G (93.59% of installed RAM)
[!!] Maximum possible memory usage: 38.0G (1372.84% of installed RAM)
[!!] Overall possible memory usage with other process exceeded memory
[OK] Slow queries: 0% (0/63K)
[OK] Highest usage of available connections: 6% (10/151)
[OK] Aborted connections: 0.00% (0/358)
[!!] Query cache may be disabled by default due to mutex contention.
[!!] Query cache efficiency: 0.0% (0 cached / 56K selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (5 temp sorts / 7K sorts)
[!!] Joins performed without indexes: 11
[!!] Temporary tables created on disk: 57% (3K on disk / 5K total)
[OK] Thread cache hit rate: 97% (10 created / 358 connections)
[!!] Table cache hit rate: 16% (863 open / 5K opened)
[OK] table_definition_cache(1400) is upper than number of tables(725)
[OK] Open file limit used: 0% (11/40K)
[OK] Table locks acquired immediately: 100% (160 immediate / 160 locks)
-------- Performance schema ------------------------------------------------------------------------
[--] Memory used by P_S: 72B
[--] Sys schema is installed.
-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is disabled.
-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 18.3% (1M used / 8M cache)
[OK] Key buffer size / total MyISAM indexes: 8.0M/43.0K
[!!] Read Key buffer hit rate: 90.7% (118 cached / 11 reads)
-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[!!] InnoDB buffer pool / data size: 40.0M/525.3M
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (240 %): 48.0M * 2/40.0M should be equal to 25%
[OK] InnoDB buffer pool instances: 1
[--] Number of InnoDB Buffer Pool Chunk : 1 for 1 Buffer Pool Instance(s)
[OK] Innodb_buffer_pool_size aligned with Innodb_buffer_pool_chunk_size & Innodb_buffer_pool_instances
[OK] InnoDB Read buffer efficiency: 99.74% (7453089 hits/ 7472246 total)
[!!] InnoDB Write Log efficiency: 72.13% (18568 hits/ 25743 total)
[OK] InnoDB log waits: 0.00% (0 waits / 7175 writes)
-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is disabled.
-------- TokuDB Metrics ----------------------------------------------------------------------------
[--] TokuDB is disabled.
-------- XtraDB Metrics ----------------------------------------------------------------------------
[--] XtraDB is disabled.
-------- Galera Metrics ----------------------------------------------------------------------------
[--] Galera is disabled.
-------- Replication Metrics -----------------------------------------------------------------------
[--] Galera Synchronous replication: NO
[--] No replication slave(s) for this server.
[--] Binlog format: ROW
[--] XA support enabled: ON
[--] Semi synchronous replication Master: Not Activated
[--] Semi synchronous replication Slave: Not Activated
[--] This is a standalone server
-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
Control warning line(s) into /var/log/mysqld.log file
Control error line(s) into /var/log/mysqld.log file
MySQL was started within the last 24 hours - recommendations may be inaccurate
Reduce your overall MySQL memory footprint for system stability
Dedicate this server to your database for highest performance.
We will suggest raising the 'join_buffer_size' until JOINs not using indexes are found.
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
Read this before increasing for MariaDB
This is MyISAM only table_cache scalability problem, InnoDB not affected.
This bug already fixed in MySQL 5.7.9 and newer MySQL versions.
Beware that open_files_limit (40000) variable
should be greater than table_open_cache (2000)
Variables to adjust:
*** MySQL's maximum memory usage is dangerously high ***
*** Add RAM before increasing MySQL buffer variables ***
query_cache_size (=0)
query_cache_type (=0)
query_cache_limit (> 1M, or use smaller result sets)
join_buffer_size (> 256.0K, or always use indexes with JOINs)
tmp_table_size (> 16M)
max_heap_table_size (> 16M)
table_open_cache (> 2000)
innodb_buffer_pool_size (>= 525.3M) if possible.
innodb_log_file_size should be (=5M) if possible, so InnoDB total log files size equals to 25% of buffer pool size.
O arquivo My.cnf é básico porque não entendo todas as diferentes variáveis;
performance-schema=0
#
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
innodb_buffer_pool_size=41943040
max_allowed_packet=268435456
open_files_limit=40000
innodb_file_per_table=1
bind-address=127.0.0.1
skip-name-resolve=1
performance_schema=ON
Alguma idéia ou conselho?
Responder1
Por que você tem um uso máximo de memória tão alto?
Aqui veremos os detalhes:
Seu MySQL está usando o número padrão de max_connections150 (o que realmente permite que esse número mais um para um usuário administrador de banco de dados se conectar; é por isso que o número mostrado é 151).
[--] Total buffers: 81.0M global + 257.1M per thread (151 max threads)
Isso nos diz quanto espaço de buffer seria usado se todas essas conexões fossem usadas de uma só vez. Se você não tiver uma calculadora em mãos, isso soma 38.903,1M (38,0G).
[!!] Maximum possible memory usage: 38.0G (1372.84% of installed RAM)
Você atingiu o máximo de 10 conexões simultâneas historicamente, então max_connectionsprovavelmente pode ser significativamente reduzido. Eu definiria como ponto de partida 20 e só aumentaria a partir daí se necessário.
[OK] Highest usage of available connections: 6% (10/151)
Mais preocupante, porém, é quanta memória foi realmente usada.
[!!] Maximum reached memory usage: 2.6G (93.59% of installed RAM)
A menos que você precise mover grandes blobs binários para dentro e para fora do banco de dados (e se precisar, reconsidere o design do seu aplicativo), você poderá reduzir significativamente o max_allowed_packet. O padrão é 64M e você pode configurá-lo para reduzir quase 3/4 do uso de memória (real e potencial). Se você receber erros de "pacote muito grande", poderá aumentá-lo, mas isso precisará de RAM para cada conexão aberta.
Responder2
Se você estiver tendo problemas de desempenho, a solução provável envolve indexar e/ou reformular consultas. Sugira que você encontre a consulta mais lenta e deixe-nos aconselhar.
Enquanto isso, duas configurações para ajustar em seus ‘pequenos’ 2,8 GB de RAM:
innodb_buffer_pool_sizedeve ser cerca de 500 milhões.max_allowed_packet = 30M