MySQL 内存使用率增长高达 100%

Question

我在具有 256gb RAM 的机器上安装了 MariaDB (10.0.20)。 内存使用量整天增长到 100%，直到重新启动它。 重新启动后，内存使用量停止增长 70% - 但在几个小时后又开始增长。

我的服务器或配置有什么问题？

Red line - memory. Falling to 0% - reboots

mysqltuner 信息：

-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 4h 50m 27s (28M q [1K qps], 305K conn, TX: 157G, RX: 29G)
[--] Reads / Writes: 14% / 86%
[--] Binary logging is disabled
[--] Physical Memory     : 251.6G
[--] Max MySQL memory    : 197.1G
[--] Other process memory: 1.5G
[--] Total buffers: 182.9G global + 48.5M per thread (300 max threads)
[--] P_S Max memory usage: 0B
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 187.3G (74.44% of installed RAM)
[OK] Maximum possible memory usage: 197.1G (78.34% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (3/28M)
[OK] Highest usage of available connections: 31% (93/300)
[OK] Aborted connections: 0.00%  (1/305591)
[OK] Query cache is disabled by default due to mutex contention on multiprocessor machines.
[OK] Sorts requiring temporary tables: 0% (1K temp sorts / 339K sorts)
[!!] Joins performed without indexes: 187
[!!] Temporary tables created on disk: 61% (170K on disk / 278K total)
[OK] Thread cache hit rate: 99% (93 created / 305K connections)
[OK] Table cache hit rate: 110% (693 open / 630 opened)
[OK] Open file limit used: 0% (63/8K)
[OK] Table locks acquired immediately: 100% (26M immediate / 26M locks)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[!!] InnoDB buffer pool / data size: 180.0G/304.6G
[OK] InnoDB buffer pool instances: 64
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version
[OK] InnoDB Read buffer efficiency: 99.98% (55901943340 hits/ 55911688878 total)
[OK] InnoDB Write log efficiency: 92.03% (161171609 hits/ 175129277 total)
[OK] InnoDB log waits: 0.00% (0 waits / 13957668 writes)

我的.cnf：

[mysqld]
#pid-file = /var/run/mysqld/mysqld.pid
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
skip-name-resolve
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

ft_min_word_len         = 3

## Cache
thread-cache-size               = 128
table-open-cache                = 1024
table-definition-cache          = 1024
query-cache-size                = 768M 
query-cache-limit               = 2048M
query-cache-type          = 0

## Per-thread Buffers
sort-buffer-size                = 16M
read-buffer-size                = 256K
read-rnd-buffer-size            = 16M
join-buffer-size                = 16M

## Temp Tables
tmp-table-size                  = 2G 
max-heap-table-size             = 2G 

## Networking
back-log                        = 300
open-files-limit        = 8192
open-files          = 1024
max-connections                 = 300
max-connect-errors              = 100
concurrent-insert       = 2
max-allowed-packet              = 512M
interactive-timeout             = 30
wait-timeout                    = 30

### Storage Engines
#default-storage-engine         = InnoDB
innodb                          = FORCE

## MyISAM
key-buffer-size                 = 10M
key_buffer_size                 = 10M
myisam-sort-buffer-size         = 128M
myisam-max-sort-file-size   = 256M

## InnoDB
innodb-buffer-pool-size         = 160G
innodb_buffer_pool_size         = 160G
innodb_buffer_pool_instances            = 150
innodb-buffer-pool-instances            = 150
innodb-log-buffer-size          = 32M
innodb-log-file-size            = 1512M
innodb-file-per-table           = 1
#innodb-open-files              = 300
innodb-flush-method     = O_DIRECT
innodb-autoinc-lock-mode    = 0
#innodb_max_dirty_pages_pct     = 0
#innodb-max-dirty-pages-pct     = 0
#innodb_io_capacity = 2000
#innodb-io-capacity = 2000
#innodb_read_io_threads = 64
#innodb_write_io_threads = 64
#innodb-read-io-threads = 64
#innodb-write-io-threads = 64


#server_audit_logging=ON
#server_audit_events=connect

## Logging
log-output                      = FILE
slow-query-log                  = 1
slow-query-log-file             = /var/log/mariadb/slow-log.log
long-query-time                 = 200
max-binlog-size         = 256M

[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb2.pid

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

Answer 1

您有一些双重引用，例如：

innodb-buffer-pool-size         = 160G

innodb_buffer_pool_size         = 160G

我认为只有“-”是有效的。

同时检查您的wait_timeout 参数：

mysql> show variables like 'innodb_lock_wait_timeout';

Answer 2

thread-cache-size               = 128  -- drop to 30
query-cache-size                = 768M  -- bad for performance, drop to 50M
query-cache-limit               = 2048M  -- make less than the query_cache_size
query-cache-type         = 0  -- good
tmp-table-size           = 2G   -- drop to 1G
max-heap-table-size      = 2G   -- drop to 1G
max-connections          = 300   -- drop to 150
innodb_buffer_pool_size  = 160G  -- good
innodb_buffer_pool_instances  = 150  -- lower to 32
slow-query-log          = 1  -- good
long-query-time         = 200  -- slow log is useless unless this is low enough, say =2

慢日志（在您更改 long_query_time 之后）将帮助您找到“[!!] 磁盘上创建的临时表：61%（磁盘上 170K / 总共 278K）”，这可能很重要。

在 Linux 中，将 swappiness 设置为 1（如 1%）。