>>  MySQLTuner 1.7.19 - 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 from Debian maintenance account.
[OK] Currently running supported MySQL version 5.7.28-0ubuntu0.16.04.2-log
[OK] Operating on 64-bit architecture

-------- Log file Recommendations ------------------------------------------------------------------
[OK] Log file /var/lib/mysql/mysql_error.log exists
[--] Log file: /var/lib/mysql/mysql_error.log(847K)
[OK] Log file /var/lib/mysql/mysql_error.log is readable.
[OK] Log file /var/lib/mysql/mysql_error.log is not empty
[OK] Log file /var/lib/mysql/mysql_error.log is smaller than 32 Mb
[!!] /var/lib/mysql/mysql_error.log contains 394 warning(s).
[!!] /var/lib/mysql/mysql_error.log contains 414 error(s).
[--] 51 start(s) detected in /var/lib/mysql/mysql_error.log
[--] 1) 2020-05-24T16:10:23.708766Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 2) 2020-05-24T08:54:38.458093Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 3) 2020-05-24T08:41:29.772932Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 4) 2020-05-23T22:38:05.721563Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 5) 2020-05-23T22:26:21.762981Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 6) 2020-05-23T21:25:41.615811Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 7) 2020-05-23T21:08:05.863216Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 8) 2020-05-23T21:02:01.394316Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 9) 2020-05-23T20:44:49.467994Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 10) 2020-05-23T18:26:04.532414Z 0 [Note] /usr/sbin/mysqld: ready for connections.
[--] 78 shutdown(s) detected in /var/lib/mysql/mysql_error.log
[--] 1) 2020-05-24T16:10:17.626644Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 2) 2020-05-24T08:54:36.847674Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 3) 2020-05-24T08:41:28.108544Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 4) 2020-05-23T22:38:04.126905Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 5) 2020-05-23T22:26:20.145052Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 6) 2020-05-23T21:25:39.897644Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 7) 2020-05-23T21:08:04.208145Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 8) 2020-05-23T21:01:59.765009Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 9) 2020-05-23T20:44:47.759965Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
[--] 10) 2020-05-23T18:26:03.260311Z 0 [Note] /usr/sbin/mysqld: Shutdown complete

-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MEMORY +MRG_MYISAM +MyISAM +PERFORMANCE_SCHEMA
[--] Data in InnoDB tables: 662.3M (Tables: 51)
[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
[!!] User 'John@%' does not specify hostname restrictions.
[!!] User 'pavel_martinez@%' does not specify hostname restrictions.
[--] There are 605 basic passwords in the list.
[!!] User 'John@%' is using weak password: qwerty in a lower, upper or capitalize derivative version.
[!!] User 'john@localhost' is using weak password: qwerty in a lower, upper or capitalize derivative version.

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

-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 13m 13s (31K q [40.121 qps], 571 conn, TX: 20M, RX: 6M)
[--] Reads / Writes: 52% / 48%
[--] Binary logging is disabled
[--] Physical Memory     : 7.8G
[--] Max MySQL memory    : 274.8G
[--] Other process memory: 0B
[--] Total buffers: 12.9G global + 536.5M per thread (500 max threads)
[--] P_S Max memory usage: 0B
[--] Galera GCache Max memory usage: 0B
[!!] Maximum reached memory usage: 20.2G (259.13% of installed RAM)
[!!] Maximum possible memory usage: 274.8G (3525.27% of installed RAM)
[!!] Overall possible memory usage with other process exceeded memory
[OK] Slow queries: 0% (4/31K)
[OK] Highest usage of available connections: 2% (14/500)
[OK] Aborted connections: 0.18%  (1/571)
[!!] 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% (0 temp sorts / 1K sorts)
[OK] No joins without indexes
[!!] Temporary tables created on disk: 49% (348 on disk / 704 total)
[OK] Thread cache hit rate: 97% (14 created / 571 connections)
[OK] Table cache hit rate: 97% (339 open / 346 opened)
[OK] table_definition_cache(4096) is upper than number of tables(330)
[OK] Open file limit used: 0% (15/10K)
[OK] Table locks acquired immediately: 100% (102 immediate / 102 locks)

-------- Performance schema ------------------------------------------------------------------------
[--] Performance schema is disabled.
[--] Memory used by P_S: 0B
[--] Sys schema is installed.

-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is disabled.

-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 18.2% (390M used / 2B cache)
[OK] Key buffer size / total MyISAM indexes: 2.0G/43.0K
[!!] Read Key buffer hit rate: 50.0% (6 cached / 3 reads)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 8
[OK] InnoDB File per table is activated
[OK] InnoDB buffer pool / data size: 5.0G/662.3M
[OK] Ratio InnoDB log file size / InnoDB Buffer pool size: 640.0M * 2/5.0G should be equal to 25%
[OK] InnoDB buffer pool instances: 5
[--] Number of InnoDB Buffer Pool Chunk : 40 for 5 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: 99.84% (2125420 hits/ 2128766 total)
[OK] InnoDB Write log efficiency: 94.30% (13117 hits/ 13910 total)
[OK] InnoDB log waits: 0.00% (0 waits / 793 writes)

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

-------- 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: ROW
[--] XA support enabled: 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/lib/mysql/mysql_error.log file
    Control error line(s) into /var/lib/mysql/mysql_error.log file
    Restrict Host for 'John'@% to John@SpecificDNSorIp
    UPDATE mysql.user SET host ='SpecificDNSorIp' WHERE user='John' AND host ='%'; FLUSH PRIVILEGES;
    Restrict Host for 'pavel_martinez'@% to pavel_martinez@SpecificDNSorIp
    UPDATE mysql.user SET host ='SpecificDNSorIp' WHERE user='pavel_martinez' AND host ='%'; FLUSH PRIVILEGES;
    Set up a Secure Password for John@% user: SET PASSWORD FOR 'John'@'%' = PASSWORD('secure_password');
    Set up a Secure Password for john@localhost user: SET PASSWORD FOR 'john'@'localhost' = PASSWORD('secure_password');
    2 user(s) used basic or weak password from basic dictionary.
    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.
    Configure your accounts with ip or subnets only, then update your configuration with skip-name-resolve=1
    Temporary table size is already large - reduce result set size
    Reduce your SELECT DISTINCT queries without LIMIT clauses
    Performance schema should be activated for better diagnostics
Variables to adjust:
  *** MySQL's maximum memory usage is dangerously high ***
  *** Add RAM before increasing MySQL buffer variables ***
    performance_schema = ON enable PFS