>>  MySQLTuner 1.7.2 - Major Hayden <[email protected]>
 >>  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] Logged in using credentials passed on the command line
[OK] Currently running supported MySQL version 5.7.29-0ubuntu0.18.04.1
[OK] Operating on 64-bit architecture

-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: ./0.err(0B)
[!!] Log file ./0.err doesn't exist
[!!] Log file ./0.err isn't readable.

-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MEMORY +MRG_MYISAM +MyISAM +PERFORMANCE_SCHEMA
[--] Data in InnoDB tables: 561M (Tables: 24)
[!!] Total fragmented tables: 1

-------- Security Recommendations ------------------------------------------------------------------
[OK] There are no anonymous accounts for any database users
[OK] All database users have passwords assigned
[!!] User 'someuser@%' hasn't specific host restriction.
[--] There are 612 basic passwords in the list.

-------- CVE Security Recommendations --------------------------------------------------------------
[OK] NO SECURITY CVE FOUND FOR YOUR VERSION

-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 12h 26m 53s (754K q [16.841 qps], 245K conn, TX: 8G, RX: 816M)
[--] Reads / Writes: 88% / 12%
[--] Binary logging is disabled
[--] Physical Memory     : 377.8G
[--] Max MySQL memory    : 5.0G
[--] Other process memory: 265.3G
[--] Total buffers: 676.0M global + 1.1M per thread (4190 max threads)
[--] P_S Max memory usage: 72B
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 975.6M (0.25% of installed RAM)
[OK] Maximum possible memory usage: 5.0G (1.33% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (0/754K)
[OK] Highest usage of available connections: 6% (282/4190)
[OK] Aborted connections: 0.00%  (6/245883)
[!!] name resolution is active : a reverse name resolution is made for each new connection and can reduce performance
[!!] Query cache may be disabled by default due to mutex contention.
[!!] Query cache efficiency: 0.0% (0 cached / 232K selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (3 temp sorts / 374 sorts)
[OK] No joins without indexes
[OK] Temporary tables created on disk: 16% (268 on disk / 1K total)
[OK] Thread cache hit rate: 91% (20K created / 245K connections)
[!!] Table cache hit rate: 19% (400 open / 2K opened)
[OK] Open file limit used: 0% (27/5K)
[OK] Table locks acquired immediately: 100% (803 immediate / 803 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% (3M used / 16M cache)
[OK] Key buffer size / total MyISAM indexes: 16.0M/43.0K
[!!] Read Key buffer hit rate: 84.4% (122 cached / 19 reads)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[!!] InnoDB buffer pool / data size: 128.0M/561.5M
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (3198.4375 %): 2.0G * 2/128.0M should be equal 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: 99.82% (74918305 hits/ 75055124 total)
[OK] InnoDB Write log efficiency: 99.42% (3686936 hits/ 3708334 total)
[OK] InnoDB log waits: 0.00% (0 waits / 21398 writes)

-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is disabled.

-------- 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:
    Run OPTIMIZE TABLE to defragment tables for better performance
      OPTIMIZE TABLE `database.mail`; -- can free 118 MB
    Total freed space after theses OPTIMIZE TABLE : 118 Mb
    Restrict Host for user@% to user@SpecificDNSorIp
    MySQL started within last 24 hours - recommendations may be inaccurate
    Configure your accounts with ip or subnets only, then update your configuration with skip-name-resolve=1
    Increase table_open_cache gradually to avoid file descriptor limits
    Read this before increasing table_open_cache over 64: http://bit.ly/1mi7c4C
    Beware that open_files_limit (5000) variable
    should be greater than table_open_cache (400)
Variables to adjust:
    query_cache_size (=0)
    query_cache_type (=0)
    query_cache_limit (> 1M, or use smaller result sets)
    table_open_cache (> 400)
    innodb_buffer_pool_size (>= 561M) if possible.
    innodb_log_file_size * innodb_log_files_in_group should be equal to 1/4 of buffer pool size (=64M) if possible.