MySqlの最大メモリは非常に高く、依然として増加を求めています

Question

私は、4コア/ 8GB RAMを搭載したVMに非常に軽いトラフィックのWordpressサイトを持っています。私は、mysqltuner.plスクリプトを実行することによってサイトのクエリが非常に遅くなることがあることに気付いたことがあります。ここでの結果は次のとおりです。

[OK] Currently running supported MySQL version 10.1.22-MariaDB 
[OK] Operating on 64-bit architecture 

-------- Log file Recommendations ------------------------------------------------------------------ 
[--] Log file: ./master_error.log(1M) 
[OK] Log file ./master_error.log exists 
[OK] Log file ./master_error.log is readable. 
[OK] Log file ./master_error.log is not empty 
[OK] Log file ./master_error.log is smaller than 32 Mb 
[!!] ./master_error.log contains 89 warning(s). 
[!!] ./master_error.log contains 24 error(s). 
[--] 4 start(s) detected in ./master_error.log 
[--] 1) 2017-03-24 3:43:22 140281079671040 [Note] /usr/sbin/mysqld: ready for connections. 
[--] 2) 2017-03-24 3:41:30 140390495832320 [Note] /usr/sbin/mysqld: ready for connections. 
[--] 3) 2017-03-24 3:37:36 139677438822656 [Note] /usr/sbin/mysqld: ready for connections. 
[--] 4) 2017-03-03 11:45:32 139685722654976 [Note] /usr/sbin/mysqld: ready for connections. 
[--] 3 shutdown(s) detected in ./master_error.log 
[--] 1) 2017-03-24 3:42:18 140390132259584 [Note] /usr/sbin/mysqld: Shutdown complete 
[--] 2) 2017-03-24 3:40:01 139677360564992 [Note] /usr/sbin/mysqld: Shutdown complete 
[--] 3) 2017-03-24 3:37:32 139685358557952 [Note] /usr/sbin/mysqld: Shutdown complete 

-------- Storage Engine Statistics ----------------------------------------------------------------- 
[--] Status: +Aria +CSV +InnoDB +MEMORY +MRG_MyISAM +MyISAM +PERFORMANCE_SCHEMA +SEQUENCE 
[--] Data in InnoDB tables: 277M (Tables: 677) 
[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: 13d 11h 25m 55s (3M q [2.764 qps], 43K conn, TX: 20G, RX: 451M) 
[--] Reads/Writes: 97%/3% 
[--] Binary logging is disabled 
[--] Physical Memory  : 7.6G 
[--] Max MySQL memory : 24.3G 
[--] Other process memory: 2.3G 
[--] Total buffers: 22.5G global + 12.5M per thread (151 max threads) 
[--] P_S Max memory usage: 0B 
[--] Galera GCache Max memory usage: 0B 
[!!] Maximum reached memory usage: 22.7G (296.63% of installed RAM) 
[!!] Maximum possible memory usage: 24.3G (318.26% of installed RAM) 
[!!] Overall possible memory usage with other process exceeded memory 
[OK] Slow queries: 0% (11K/3M) 
[OK] Highest usage of available connections: 10% (16/151) 
[OK] Aborted connections: 0.00% (2/43596) 
[--] Skipped name resolution test due to skip_networking=ON in system variables. 
[!!] Query cache may be disabled by default due to mutex contention. 
[OK] Query cache efficiency: 40.2% (1M cached/4M selects) 
[OK] Query cache prunes per day: 0 
[OK] Sorts requiring temporary tables: 0% (7 temp sorts/71K sorts) 
[OK] No joins without indexes 
[!!] Temporary tables created on disk: 51% (44K on disk/86K total) 
[OK] Thread cache hit rate: 99% (23 created/43K connections) 
[OK] Table cache hit rate: 22% (854 open/3K opened) 
[OK] Open file limit used: 0% (60/16K) 
[OK] Table locks acquired immediately: 100% (1M immediate/1M 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: 4 thread(s). 
[--] Using default value is good enough for your version (10.1.22-MariaDB) 

-------- MyISAM Metrics ---------------------------------------------------------------------------- 
[!!] Key buffer used: 18.9% (2B used/11B cache) 
[OK] Key buffer size/total MyISAM indexes: 11.0G/123.0K 
[OK] Read Key buffer hit rate: 99.3% (1K cached/9 reads) 
[OK] Write Key buffer hit rate: 100.0% (60 cached/60 writes) 

-------- InnoDB Metrics ---------------------------------------------------------------------------- 
[--] InnoDB is enabled. 
[--] InnoDB Thread Concurrency: 0 
[OK] InnoDB File per table is activated 
[OK] InnoDB buffer pool/data size: 11.0G/278.0M 
[!!] Ratio InnoDB log file size/InnoDB Buffer pool size (1.77556818181818 %): 100.0M * 2/11.0G should be equal 25% 
[!!] InnoDB buffer pool instances: 8 
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version 
[OK] InnoDB Read buffer efficiency: 100.00% (111655571 hits/ 111658256 total) 
[OK] InnoDB Write log efficiency: 97.88% (1070445 hits/ 1093608 total) 
[OK] InnoDB log waits: 0.00% (0 waits/23163 writes) 

-------- AriaDB Metrics ---------------------------------------------------------------------------- 
[--] AriaDB is enabled. 
[OK] Aria pagecache size/total Aria indexes: 128.0M/1B 
[OK] Aria pagecache hit rate: 97.3% (1M cached/35K 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 ./master_error.log file 
Control error line(s) into ./master_error.log file 
Reduce your overall MySQL memory footprint for system stability 
Dedicate this server to your database for highest performance. 
When making adjustments, make tmp_table_size/max_heap_table_size equal 
Reduce your SELECT DISTINCT queries which have no LIMIT clause 
Performance should be activated for better diagnostics 
Consider installing Sys schema from https://github.com/mysql/mysql-sys 
Variables to adjust: 
    *** MySQL's maximum memory usage is dangerously high *** 
    *** Add RAM before increasing MySQL buffer variables *** 
    query_cache_type (=0) 
    tmp_table_size (> 64M) 
    max_heap_table_size (> 64M) 
    performance_schema = ON enable PFS 
    innodb_log_file_size * innodb_log_files_in_group should be equals to 1/4 of buffer pool size (=5G) if possible. 
    innodb_buffer_pool_instances(=11) 

...と、ここは私のserver.confです：

[mysql] 
no-auto-rehash 

[myisamchk] 
key_buffer_size = 256M 
sort_buffer_size = 256M 
read_buffer = 2M 
write_buffer = 2M 

[mysqlhotcopy] 
interactive-timeout 

[mysqld] 
# Connection and Thread variables 
socket = /var/lib/mysql/mysql.sock 
pid-file=/var/lib/mysql/maria.pid 
tmpdir = /run/mariadb 
optimizer_search_depth=0 
bind-address = 127.0.0.1 

skip-external-locking 
key_buffer_size = 11G 
max_allowed_packet = 1M 
table_open_cache = 4000 
sort_buffer_size = 2M 
read_buffer_size = 2M 
read_rnd_buffer_size = 8M 
myisam_sort_buffer_size = 64M 
thread_cache_size = 8 
query_cache_size = 256M 
query_cache_limit = 4M 
tmp_table_size = 64M 
max_heap_table_size = 64M 

# Try number of CPU's*2 for thread_concurrency 
thread_concurrency = 2 

innodb_data_home_dir = /var/lib/mysql 
innodb_data_file_path = ibdata1:10M:autoextend 
innodb_log_group_home_dir = /var/lib/mysql 
innodb_buffer_pool_size = 11G 
innodb_additional_mem_pool_size = 20M 
innodb_log_file_size = 100M 
innodb_log_buffer_size = 8M 
innodb_flush_log_at_trx_commit = 0 
innodb_lock_wait_timeout = 50 

innodb_thread_concurrency = 0 
innodb_read_io_threads = 64 
innodb_write_io_threads = 64 


# Security variables 
local_infile     = 0 
secure_auth     = 1 
sql_mode      = TRADITIONAL,NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES 
skip_name_resolve    = 1 
symbolic-links=0 
skip-networking 

### LOGS ### 
# MySQL error log 
log_error      = master_error.log 
log_warnings     = 2 
# innodb_print_all_deadlocks  = 1 

# Slow Query Log 
slow_query_log_file   = master_slow.log 
slow_query_log     = 1 
log_queries_not_using_indexes = 1 
long_query_time    = 0.5 
min_examined_row_limit   = 100 

# General Query Log 
general_log_file    = master_general.log 
general_log     = 0 

[mysqldump] 
quick 
max_allowed_packet = 16M 

いくつかのものは、このような4000のtable_open_cacheのを持つなど、明らかに間違っているようですが、私はいくつかの専門家かどうかを確認したかったです私が設定をしつこかせる前にいくつかの提案がありました。また、そのような高いメモリ使用量がどのようにあるかもしれないかについて混乱していますが、依然として価値をさらに高めるための推奨事項です。

Answer 1

mysqltunerは完全ではありません。しかし、にはには実際には8GBのRAMには高すぎる設定があります...

8GBのRAMと本質的にMyISAMテーブルはありませんか？ key_buffer_sizeは20Mのようになります。ではなく11G！ mysqltuner人が聞いている場合は、そのテストを修正する必要があります。

また、innodb_buffer_pool_sizeはRAMを吹き飛ばすのを防ぐため、5Gでなければなりません！ （そしてinnodb_buffer_pool_instancesを5に変更する）

query_cache_sizeは、約50Mを超えると効率が悪くなります。

log_queries_not_using_indexes slowlogを不必要に混乱させる。消して。

アリア - 1Bは1バイトか10億バイトですか？ （mysqltunerの別のバグ）。

あなたはRAMに過剰割り当てRAMを持っているので、おそらく交換しています。スワッピングは、が非常にです。これは、すべてのバッファがRAMに常駐していると仮定しているためです。