MySQLTuner report

 >>  MySQLTuner 1.7.9 - 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 10.1.26-MariaDB-0+deb9u1
[OK] Operating on 64-bit architecture

-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: /var/log/mysql/error.log(8K)
[OK] Log file /var/log/mysql/error.log exists
[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 68 warning(s).
[OK] /var/log/mysql/error.log doesn't contain any error.
[--] 0 start(s) detected in /var/log/mysql/error.log
[--] 0 shutdown(s) detected in /var/log/mysql/error.log

-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +Aria +CSV +InnoDB +MEMORY +MRG_MyISAM +MyISAM +PERFORMANCE_SCHEMA +SEQUENCE
[--] Data in InnoDB tables: 32.8G (Tables: 666)
[--] Data in MEMORY tables: 6.3M (Tables: 3)
[OK] Total fragmented tables: 0

-------- Security Recommendations ------------------------------------------------------------------
[OK] There are no anonymous accounts for any database users
[OK] All database users have passwords assigned
[!!] User 'shopping-fuchs24@%' does not specify hostname restrictions.
[!!] There is no basic password file list!

-------- CVE Security Recommendations --------------------------------------------------------------
[--] Skipped due to --cvefile option undefined

-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 7d 22h 54m 59s (62M q [91.078 qps], 303K conn, TX: 784G, RX: 19G)
[--] Reads / Writes: 95% / 5%
[--] Binary logging is disabled
[--] Physical Memory     : 62.9G
[--] Max MySQL memory    : 38.1G
[--] Other process memory: 676.3M
[--] Total buffers: 35.2G global + 19.2M per thread (151 max threads)
[--] P_S Max memory usage: 92M
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 36.4G (57.82% of installed RAM)
[OK] Maximum possible memory usage: 38.1G (60.62% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (0/62M)
[OK] Highest usage of available connections: 37% (57/151)
[!!] Aborted connections: 4.32%  (13117/303717)
[!!] name resolution is active : a reverse name resolution is made for each new connection and can reduce performance
[OK] Query cache is disabled by default due to mutex contention on multiprocessor machines.
[OK] Sorts requiring temporary tables: 0% (142 temp sorts / 19M sorts)
[!!] Temporary tables created on disk: 92% (17M on disk / 19M total)
[OK] Thread cache hit rate: 98% (3K created / 303K connections)
[OK] Table cache hit rate: 99% (2K open / 2K opened)
[OK] Open file limit used: 0% (84/16K)
[OK] Table locks acquired immediately: 99% (121M immediate / 121M locks)

-------- Performance schema ------------------------------------------------------------------------
[--] Memory used by P_S: 92.7M
[--] Sys schema isn't installed.

-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is enabled.
[--] Thread Pool Size: 24 thread(s).
[--] Using default value is good enough for your version (10.1.26-MariaDB-0+deb9u1)

-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 19.1% (1B used / 5B cache)
[OK] Key buffer size / total MyISAM indexes: 5.0G/123.0K
[OK] Read Key buffer hit rate: 97.9% (1K cached / 25 reads)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[!!] InnoDB buffer pool / data size: 30.0G/32.8G
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (6.66666666666667 %): 1.0G * 2/30.0G should be equal 25%
[!!] InnoDB buffer pool instances: 15
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version
[OK] InnoDB Read buffer efficiency: 100.00% (411255144335 hits/ 411255887458 total)
[!!] InnoDB Write Log efficiency: 85.63% (11243174 hits/ 13130255 total)
[OK] InnoDB log waits: 0.00% (0 waits / 1887081 writes)

-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is enabled.
[OK] Aria pagecache size / total Aria indexes: 128.0M/1B
[!!] Aria pagecache hit rate: 94.0% (278M cached / 16M 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.
[--] Binlog format: STATEMENT
[--] 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/mysql/error.log file
    Restrict Host for user@% to user@SpecificDNSorIp
    Reduce or eliminate unclosed connections and network issues
    Configure your accounts with ip or subnets only, then update your configuration with skip-name-resolve=1
    Adjust your join queries to always utilize indexes
    When making adjustments, make tmp_table_size/max_heap_table_size equal
    Reduce your SELECT DISTINCT queries which have no LIMIT clause
    Consider installing Sys schema from https://github.com/mysql/mysql-sys
    Before changing innodb_log_file_size and/or innodb_log_files_in_group read this: http://bit.ly/2wgkDvS
Variables to adjust:
    join_buffer_size (> 8.0M, or always use indexes with JOINs)
    tmp_table_size (> 64M)
    max_heap_table_size (> 64M)
    innodb_buffer_pool_size (>= 32.8G) if possible.
    innodb_log_file_size should be (=3G) if possible, so InnoDB total log files size equals to 25% of buffer pool size.
    innodb_buffer_pool_instances(=30)