MYSQL Tuner

 >>  MySQLTuner 1.7.15 - 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
[--] Performing tests on <redacted>.rds.amazonaws.com:3306
[OK] Logged in using credentials passed on the command line
[--] Assuming 16384 MB of physical memory
[--] Assuming 100 MB of swap space
[OK] Currently running supported MySQL version 5.6.43-log

-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: /rdsdbdata/db/ip-172-17-3-73.err(0B)
[!!] Log file /rdsdbdata/db/ip-172-17-3-73.err doesn't exist
[!!] Log file /rdsdbdata/db/ip-172-17-3-73.err isn't readable.

-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MEMORY +MRG_MYISAM +MyISAM +PERFORMANCE_SCHEMA
[--] Data in InnoDB tables: 377.4G (Tables: 61)
[!!] Total fragmented tables: 1

-------- 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
[!!] User '<redacted>@*' has no password set.
[!!] User '<redacted>@%' has no password set.
[!!] User '<redacted>@%' does not specify hostname restrictions.
[!!] User '<redacted>@%' does not specify hostname restrictions.
[!!] User '<redacted>@%' does not specify hostname restrictions.
[!!] User '<redacted>@%' does not specify hostname restrictions.
[--] There are 618 basic passwords in the list.

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

-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 17d 19h 40m 49s (1B q [768.965 qps], 6M conn, TX: 10371G, RX: 704G)
[--] Reads / Writes: 84% / 16%
[--] Binary logging is enabled (GTID MODE: OFF)
[--] Physical Memory     : 16.0G
[--] Max MySQL memory    : 13.2G
[--] Other process memory: 0B
[--] Total buffers: 11.3G global + 1.5M per thread (1282 max threads)
[--] P_S Max memory usage: 0B
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 12.3G (77.16% of installed RAM)
[OK] Maximum possible memory usage: 13.2G (82.48% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (3M/1B)
[OK] Highest usage of available connections: 54% (701/1282)
[OK] Aborted connections: 0.00%  (1/6143636)
[!!] 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 / 975M selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (82K temp sorts / 193M sorts)
[!!] Joins performed without indexes: 6151
[!!] Temporary tables created on disk: 99% (192M on disk / 192M total)
[OK] Thread cache hit rate: 92% (448K created / 6M connections)
[!!] Table cache hit rate: 10% (2K open / 19K opened)
[OK] Open file limit used: 0% (379/65K)
[OK] Table locks acquired immediately: 100% (1B immediate / 1B locks)
[OK] Binlog cache memory access: 98.21% (182341100 Memory / 185657272 Total)

-------- 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: 18.3% (3M used / 16M cache)
[OK] Key buffer size / total MyISAM indexes: 16.0M/2.4M
[OK] Read Key buffer hit rate: 100.0% (263M cached / 24 reads)
[!!] Write Key buffer hit rate: 0.0% (199M cached / 0 writes)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[!!] InnoDB buffer pool / data size: 11.3G/377.4G
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (2.21817866735985 %): 128.0M * 2/11.3G should be equal to 25%
[!!] InnoDB buffer pool instances: 8
[--] InnoDB Buffer Pool Chunk Size not used or defined in your version
[OK] InnoDB Read buffer efficiency: 99.40% (252149023619 hits/ 253674949410 total)
[OK] InnoDB Write log efficiency: 92.83% (1310145641 hits/ 1411414399 total)
[OK] InnoDB log waits: 0.00% (0 waits / 101268758 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: MIXED
[--] XA support enabled: ON
[--] Semi synchronous replication Master: Not Activated
[--] Semi synchronous replication Slave: Not Activated
[--] This is a standalone server

-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
    Run OPTIMIZE TABLE to defragment tables for better performance
      OPTIMIZE TABLE `<redacted>`.`Podcast`; -- can free 8460 MB
    Total freed space after theses OPTIMIZE TABLE : 8460 Mb
    Set up a Password for user with the following SQL statement ( SET PASSWORD FOR 'user'@'SpecificDNSorIp' = PASSWORD('secure_password'); )
    Restrict Host for user@% to user@SpecificDNSorIp
    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
    Increase table_open_cache gradually to avoid file descriptor limits
    Read this before increasing table_open_cache over 64: https://bit.ly/1mi7c4C
    Read this before increasing for MariaDB https://mariadb.com/kb/en/library/optimizing-table_open_cache/
    This is MyISAM only table_cache scalability problem, InnoDB not affected.
    See more details here: https://bugs.mysql.com/bug.php?id=49177
    This bug already fixed in MySQL 5.7.9 and newer MySQL versions.
    Beware that open_files_limit (65535) variable
    should be greater than table_open_cache (2000)
    Performance schema should be activated for better diagnostics
    Before changing innodb_log_file_size and/or innodb_log_files_in_group read this: https://bit.ly/2TcGgtU
Variables to adjust:
    query_cache_size (=0)
    query_cache_type (=0)
    query_cache_limit (> 1M, or use smaller result sets)
    join_buffer_size (> 256.0K, or always use indexes with JOINs)
    tmp_table_size (> 16M)
    max_heap_table_size (> 16M)
    table_open_cache (> 2000)
    performance_schema = ON enable PFS
    innodb_buffer_pool_size (>= 377.4G) 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(=11)