root@db:~# ./mysqltuner.pl
 >>  MySQLTuner 1.7.20 - Major Hayden <[email protected]>
 >>  Bug reports, feature requests, and downloads at http://mysqltuner.pl/
 >>  Run with '--help' for additional options and output filtering

[--] Skipped version check for MySQLTuner script
[OK] Logged in using credentials from Debian maintenance account.
[OK] Currently running supported MySQL version 10.3.25-MariaDB-0+deb10u1
[OK] Operating on 64-bit architecture

-------- Log file Recommendations ------------------------------------------------------------------
[OK] Log file /var/log/mysql/error.log exists
[--] Log file: /var/log/mysql/error.log(18K)
[OK] Log file /var/log/mysql/error.log is readable.
[OK] Log file /var/log/mysql/error.log is not empty
[OK] Log file /var/log/mysql/error.log is smaller than 32 Mb
[!!] /var/log/mysql/error.log contains 1 warning(s).
[!!] /var/log/mysql/error.log contains 1 error(s).
[--] 7 start(s) detected in /var/log/mysql/error.log
[--] 1) 2020-11-19 11:14:26 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 2) 2020-11-19 11:07:02 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 3) 2020-11-19 10:56:08 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 4) 2020-11-19 10:41:07 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 5) 2020-11-19 10:35:19 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 6) 2020-11-19 10:31:39 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 7) 2020-11-19 10:30:06 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 7 shutdown(s) detected in /var/log/mysql/error.log
[--] 1) 2020-11-19 11:13:22 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 2) 2020-11-19 11:07:00 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 3) 2020-11-19 10:56:05 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 4) 2020-11-19 10:40:59 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 5) 2020-11-19 10:35:17 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 6) 2020-11-19 10:31:38 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 7) 2020-11-19 10:30:06 0 [Note] /usr/sbin/mysqld: Shutdown complete

-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +Aria +CSV +InnoDB +MEMORY +MRG_MyISAM +MyISAM +PERFORMANCE_SCHEMA +SEQUENCE
[--] Data in MyISAM tables: 3.1G (Tables: 416)
[--] Data in InnoDB tables: 27.0G (Tables: 482)
[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: 4h 43m 9s (2M q [120.623 qps], 695 conn, TX: 357M, RX: 205M)
[--] Reads / Writes: 60% / 40%
[--] Binary logging is disabled
[--] Physical Memory     : 15.3G
[--] Max MySQL memory    : 315.8G
[--] Other process memory: 0B
[--] Total buffers: 10.3G global + 1.0G per thread (300 max threads)
[--] P_S Max memory usage: 0B
[--] Galera GCache Max memory usage: 0B
[!!] Maximum reached memory usage: 15.4G (100.54% of installed RAM)
[!!] Maximum possible memory usage: 315.8G (2064.21% of installed RAM)
[!!] Overall possible memory usage with other process exceeded memory
[OK] Slow queries: 0% (4/2M)
[OK] Highest usage of available connections: 1% (5/300)
[OK] Aborted connections: 0.00%  (0/695)
[!!] Query cache may be disabled by default due to mutex contention.
[OK] Query cache efficiency: 46.8% (1M cached / 2M selects)
[!!] Query cache prunes per day: 687395
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 127 sorts)
[OK] No joins without indexes
[!!] Temporary tables created on disk: 26% (295 on disk / 1K total)
[OK] Thread cache hit rate: 96% (27 created / 695 connections)
[OK] Table cache hit rate: 96% (649 open / 670 opened)
[!!] table_definition_cache(400) is lower than number of tables(1057)
[OK] Open file limit used: 2% (887/32K)
[OK] Table locks acquired immediately: 100% (1K immediate / 1K 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: 8 thread(s).
[--] Using default value is good enough for your version (10.3.25-MariaDB-0+deb10u1)

-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 43.9% (9M used / 20M cache)
[OK] Key buffer size / total MyISAM indexes: 20.0M/1.2G
[OK] Read Key buffer hit rate: 98.7% (400K cached / 5K reads)
[!!] Write Key buffer hit rate: 8.6% (158K cached / 13K writes)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[!!] InnoDB buffer pool / data size: 10.0G/27.0G
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (0.9375 %): 48.0M * 2/10.0G should be equal to 25%
[!!] InnoDB buffer pool instances: 8
[--] Number of InnoDB Buffer Pool Chunk : 80 for 8 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: 100.00% (3021289867 hits/ 3021351222 total)
[!!] InnoDB Write Log efficiency: 71.74% (2102121 hits/ 2930249 total)
[OK] InnoDB log waits: 0.00% (0 waits / 828128 writes)

-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is enabled.
[OK] Aria pagecache size / total Aria indexes: 128.0M/1B
[OK] Aria pagecache hit rate: 98.1% (15K cached / 295 reads)

-------- 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: MIXED
[--] XA support enabled: ON
[--] Semi synchronous replication Master: OFF
[--] Semi synchronous replication Slave: OFF
[--] This is a standalone server

-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
    Control warning line(s) into /var/log/mysql/error.log file
    Control error line(s) into /var/log/mysql/error.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.
    When making adjustments, make tmp_table_size/max_heap_table_size equal
    Reduce your SELECT DISTINCT queries which have no LIMIT clause
    Performance schema should be activated for better diagnostics
    Consider installing Sys schema from https://github.com/mysql/mysql-sys for MySQL
    Consider installing Sys schema from https://github.com/FromDual/mariadb-sys for MariaDB
    Before changing innodb_log_file_size and/or innodb_log_files_in_group read this: https://bit.ly/2TcGgtU
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_size (> 20M)
    tmp_table_size (> 64M)
    max_heap_table_size (> 64M)
    table_definition_cache(400) > 1057 or -1 (autosizing if supported)
    performance_schema = ON enable PFS
    innodb_buffer_pool_size (>= 27.0G) if possible.
    innodb_log_file_size should be (=1G) if possible, so InnoDB total log files size equals to 25% of buffer pool size.
    innodb_buffer_pool_instances(=10)