Here are the results of MySQLTuner:

[--] Skipped version check for MySQLTuner script
[OK] Logged in using credentials from debian maintenance account.
[OK] Currently running supported MySQL version 5.7.21-0ubuntu0.16.04.1
[OK] Operating on 64-bit architecture

-------- Log file Recommendations ------------------------------------------------------------------
[--] Log file: /var/log/mysql/error.log(15K)
[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 11 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 -----------------------------------------------------------------
[--] Data in InnoDB tables: 3M (Tables: 54)
[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 'admin_default@%' hasn't specific host restriction.
[!!] User 'admin_rpgc@%' hasn't specific host restriction.
[!!] There is no basic password file list!

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

-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 34d 13h 45m 15s (485K q [0.163 qps], 165K conn, TX: 520M, RX: 83M)
[--] Reads / Writes: 94% / 6%
[--] Binary logging is disabled
[--] Physical Memory     : 2.0G
[--] Max MySQL memory    : 299.5M
[--] Other process memory: 157.2M
[--] Total buffers: 177.0M global + 1.8M per thread (70 max threads)
[--] P_S Max memory usage: 72B
[--] Galera GCache Max memory usage: 0B
[OK] Maximum reached memory usage: 192.8M (9.41% of installed RAM)
[OK] Maximum possible memory usage: 299.5M (14.62% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (0/485K)
[OK] Highest usage of available connections: 12% (9/70)
[!!] Aborted connections: 51.53%  (85302/165532)
[!!] 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 / 157K selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (196 temp sorts / 44K sorts)
[OK] No joins without indexes
[!!] Temporary tables created on disk: 46% (27K on disk / 59K total)
[OK] Thread cache hit rate: 99% (9 created / 165K connections)
[!!] Table cache hit rate: 0% (64 open / 269K opened)
[OK] Open file limit used: 0% (4/1K)
[OK] Table locks acquired immediately: 100% (10K immediate / 10K locks)

-------- Performance schema ------------------------------------------------------------------------
[--] Memory used by P_S: 72B
[--] Sys schema is installed.

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

-------- MyISAM Metrics ----------------------------------------------------------------------------
[!!] Key buffer used: 18.2% (3M used / 16M cache)
[OK] Key buffer size / total MyISAM indexes: 16.0M/43.0K
[!!] Read Key buffer hit rate: 62.9% (272 cached / 101 reads)

-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[--] InnoDB Thread Concurrency: 0
[OK] InnoDB File per table is activated
[OK] InnoDB buffer pool / data size: 128.0M/3.6M
[!!] Ratio InnoDB log file size / InnoDB Buffer pool size (75 %): 48.0M * 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: 100.00% (4276367247 hits/ 4276367871 total)
[!!] InnoDB Write Log efficiency: 278.6% (19527 hits/ 7009 total)
[OK] InnoDB log waits: 0.00% (0 waits / 26536 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.
[--] 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/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
    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: http://bit . ly/1mi7c4C
    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 (1024) variable
    should be greater than table_open_cache (64)
    Read this before changing innodb_log_file_size and/or innodb_log_files_in_group: http://bit . ly/2wgkDvS
Variables to adjust:
    query_cache_size (=0)
    query_cache_type (=0)
    query_cache_limit (> 1M, or use smaller result sets)
    tmp_table_size (> 16M)
    max_heap_table_size (> 16M)
    table_open_cache (> 64)
    innodb_log_file_size should be (=16M) if possible, so InnoDB total log files size equals to 25% of buffer pool size.

Should I enable query_cache?

And is there a way to reduce the creation of so many temporary tables?

Under the variables to adjust section, do those sound like good choices? I have a server with 2GB RAM and don't use all of it, would increasing max usage help at all?








ulimit -a

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 289215
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 10240
cpu time               (seconds, -t) unlimited
max user processes              (-u) 289215
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

df -h

Filesystem      Size  Used Avail Use% Mounted on
/dev/simfs       60G  3.8G   57G   7% /
devtmpfs        1.0G     0  1.0G   0% /dev
tmpfs           1.0G     0  1.0G   0% /dev/shm
tmpfs           1.0G  104M  921M  11% /run
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           1.0G     0  1.0G   0% /sys/fs/cgroup
none            1.0G     0  1.0G   0% /run/shm

free -m

              total        used        free      shared  buff/cache   available
Mem:           2048        1109         187         263         750         827
Swap:          2048         246        1801
  • Additional information request, please. current complete my.cnf-ini complete error.log Text results of: A) SHOW GLOBAL STATUS; B) SHOW GLOBAL VARIABLES; C) SHOW ENGINE INNODB STATUS; Optional very helpful information, if available includes - htop OR top for most active apps, ulimit -a for a linux/unix list of limits, iostat -x when system is busy for an idea of IOPS by device, df -h for a linux/unix free space list by device, free -m for a linux/unix free memory report for additional suggestions. Aborted connections appears to be a problem. Apr 10, 2018 at 12:13
  • 1
    Updated my post
    – SvEnjoyPro
    Apr 10, 2018 at 22:49

3 Answers 3


No, do not enable Query Cache. V 8.0 announcements include QC will NOT be available and will be REMOVED. Besides, QC only encourages low quality development.

Suggestions for your my.cnf-ini [mysqld] section

tmp_table_size=40M  # from 16M to reduce TT creations
max_heap_table_size=40M  # from 16M - should ALWAYS be same size as tmp_table_size
max_connections=36  # from 70 because in 30+ days, you had 9 max_used_connections
key_buffer_size=8M  # from 16M - because only 3M used
log_warnings=2  # for addl error.log info on connection errors
  • 1
    I updated my post to include my.cnf. It doesn't seem to have tmp_table_size or max_heap_table_size.
    – SvEnjoyPro
    Apr 10, 2018 at 22:50
  • @SvEnjoyPro To be ADDED to [mysqld] section, please. Stop Services, shutdown/restart to be effective. Will try to complete analysis by Friday 8 AM CT USA. Apr 10, 2018 at 23:28
  • @SvEnjoyPro When would you have time to use SKYPE and review TOP report, my current analysis using Screen Share, microphone and speakers? English is my only language. 30 minutes should be enough time. SKYPE search for Wilson Hauck Birmingham AL USA or wlhauck at aol dot com to invite me to connect. Will be out of my office all Wed afternoon today. Alternative and more time consuming would be dba.stackexchange.com's chat function, if required. Apr 11, 2018 at 9:37
  • @SvEnjoyPro www.translate.google.com is helpful in overcoming my English only situation. We could still review my analysis results thru SKYPE late in your working day. I am [email protected] OR search for Wilson Hauck Birmingham AL USA. Thanks May 19, 2018 at 6:25

Additional Suggestions to be considered.

ulimit -n 5000
in Ubunto to enable more file handle capacity from 1K current OS limit.

In your my.cnf-ini [mysqld] section, more Suggestions on 4/13/2018 early AM

max_connect_errors=10  # why allow hacker/cracker 100 opportunities to guess PW?
thread_cache_size=32  # from 8 to improve thread concurrency
lock_wait_timeout=300  # from 1year (3153600 seconds) for reasonable timeout
expire_logs_days=30  # from 0 for limited historical logs
innodb_print_all_deadlocks=ON  # from OFF - you will WANT the information for corrective action
innodb_read_ahead_threshold=8  # from 56 to read next EXTENT earlier
innodb_stats_sample_pages=32  # from 8 for more accurate NDX cardinality
max_join_size=1000000000  # from a HUGE number for 1Billion row limit
max_seeks_for_key=32  # from a HUGE number, after nn NDX tries, scan table
max_write_lock_count=32  # from a HUGE number, give RD a chance after nn locks
table_open_cache=1024  # from 64 to reduce table_open_cache_misses
open_files_limit=3K  # from 1024 to support volume of tables, definitions, files used
query_cache_size=0  # from 1M - QC not being used today
query_cache_limit=1K  # to conserve RAM for other purposes, QC not used
query_cache_min_res_unit=512  # for more RESULTS in QC, if ever used
slow_query_log=ON  # from OFF  to be aware of ATTENTION needed to improve

My next day in office will be May 2, 2018. Good luck

  • @svenjoypro Making any progress with your instance? May 2, 2018 at 18:40
  • @svenjoypro Are you making any progress with your instance? The link in your profile does not work, today. Jun 11, 2018 at 23:29

You have a tiny dataset on a tiny server (or VM). The SlowLog will indicate that some queries are poorly written; fix them. You "can't tune your way out of a performance problem".

Do not turn on the QC.

(I might have more to say, but the VARIABLES and GLOBAL STATUS have expired on pastebin.)

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