title: table_open_cache not working mariadb
body: <p>today i was optimizing my mariadb since my website was running too slow
  My machine is a Centos 7 , 4 gbs ram 3 cpu</p>
  
  <p>i runned a script called mysql_tuner.pl and the results were:</p>
  
  <pre><code>        -- MYSQL PERFORMANCE TUNING PRIMER --
               - By: Matthew Montgomery -
  
  MySQL Version 5.5.40-MariaDB x86_64
  
  Uptime = 0 days 0 hrs 0 min 12 sec
  Avg. qps = 1
  Total Questions = 16
  Threads Connected = 1
  
  Warning: Server has not been running for at least 48hrs.
  It may not be safe to use these recommendations
  
  To find out more information on how each of these
  runtime variables effects performance visit:
  http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html
  Visit http://www.mysql.com/products/enterprise/advisors.html
  for info about MySQL's Enterprise Monitoring and Advisory Service
  
  SLOW QUERIES
  The slow query log is NOT enabled.
  Current long_query_time = 10.000000 sec.
  You have 0 out of 37 that take longer than 10.000000 sec. to complete
  Your long_query_time seems to be fine
  
  BINARY UPDATE LOG
  The binary update log is NOT enabled.
  You will not be able to do point in time recovery
  See http://dev.mysql.com/doc/refman/5.5/en/point-in-time-recovery.html
  
  WORKER THREADS
  Current thread_cache_size = 0
  Current threads_cached = 0
  Current threads_per_sec = 1
  Historic threads_per_sec = 1
  Your thread_cache_size is fine
  
  MAX CONNECTIONS
  Current max_connections = 151
  Current threads_connected = 1
  Historic max_used_connections = 1
  The number of used connections is 0% of the configured maximum.
  You are using less than 10% of your configured max_connections.
  Lowering max_connections could help to avoid an over-allocation of memory
  See "MEMORY USAGE" section to make sure you are not over-allocating
  
  INNODB STATUS
  Current InnoDB index space = 110 M
  Current InnoDB data space = 1.39 G
  Current InnoDB buffer pool free = 71 %
  Current innodb_buffer_pool_size = 128 M
  Depending on how much space your innodb indexes take up it may be safe
  to increase this value to up to 2 / 3 of total system memory
  
  MEMORY USAGE
  Max Memory Ever Allocated : 274 M
  Configured Max Per-thread Buffers : 419 M
  Configured Max Global Buffers : 272 M
  Configured Max Memory Limit : 691 M
  Physical Memory : 4.00 G
  Max memory limit seem to be within acceptable norms
  
  KEY BUFFER
  No key reads?!
  Seriously look into using some indexes
  Current MyISAM index space = 58 M
  Current key_buffer_size = 128 M
  Key cache miss rate is 1 : 0
  Key buffer free ratio = 81 %
  Your key_buffer_size seems to be fine
  
  QUERY CACHE
  Query cache is supported but not enabled
  Perhaps you should set the query_cache_size
  
  SORT OPERATIONS
  Current sort_buffer_size = 2 M
  Current read_rnd_buffer_size = 256 K
  No sort operations have been performed
  Sort buffer seems to be fine
  
  JOINS
  ./mysql_tuner.pl: line 402: export: `2097152': not a valid identifier
  Current join_buffer_size = 132.00 K
  You have had 0 queries where a join could not use an index properly
  Your joins seem to be using indexes properly
  
  OPEN FILES LIMIT
  Current open_files_limit = 1024 files
  The open_files_limit should typically be set to at least 2x-3x
  that of table_cache if you have heavy MyISAM usage.
  Your open_files_limit value seems to be fine
  
  TABLE CACHE
  Current table_open_cache = 400 tables
  Current table_definition_cache = 400 tables
  You have a total of 801 tables
  You have 400 open tables.
  Current table_cache hit rate is 16%
  , while 100% of your table cache is in use
  You should probably increase your table_cache
  You should probably increase your table_definition_cache value.
  
  TEMP TABLES
  Current max_heap_table_size = 16 M
  Current tmp_table_size = 16 M
  Of 347 temp tables, 9% were created on disk
  Created disk tmp tables ratio seems fine
  
  TABLE SCANS
  Current read_buffer_size = 128 K
  Current table scan ratio = 28 : 1
  read_buffer_size seems to be fine
  
  TABLE LOCKING
  Current Lock Wait ratio = 0 : 295
  Your table locking seems to be fine
  </code></pre>
  
  <p>so, i realized that i should raise table_open_cache...
  even i confirmed throught mysql command line</p>
  
  <pre><code>+--------------------+
  | @@table_open_cache |
  +--------------------+
  |                400 |
  +--------------------+
  1 row in set (0.00 sec)
  
  MariaDB [(none)]&gt;
  </code></pre>
  
  <p>ok , so i ran into my.cnf</p>
  
  <p>and edited like this:</p>
  
  <pre><code>[mysqld]
  datadir=/var/lib/mysql
  socket=/var/lib/mysql/mysql.sock
  
  #table_cache = 1000
  #max_open_files = 4000
  #max_connections = 800
  key_buffer_size = 60M
  max_allowed_packet = 1G
  table_open_cache = 2000
  table_definition_cache = 2000
  #sort_buffer_size = 2M
  #read_buffer_size = 1M
  #read_rnd_buffer_size = 8M
  #myisam_sort_buffer_size = 64M
  #thread_cache_size = 15
  #query_cache_size = 32M
  #thread_concurrency = 8
  innodb_buffer_pool_size = 2G
  
  # Disabling symbolic-links is recommended to prevent assorted security risks
  symbolic-links=0
  
  # Recommended in standard MySQL setup
  sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES 
  
  [mysqld_safe]
  log-error=/var/log/mysqld.log
  pid-file=/var/run/mysqld/mysqld.pid
  
  [client]
  default-character-set=utf8
  
  [mysql]
  default-character-set=utf8
  </code></pre>
  
  <p>but table_open_cache is still 400! 
  my server is reading all the other variables, except table_open_cache</p>
  
  <p>results after changing the cnf file</p>
  
  <pre><code>TABLE CACHE
  Current table_open_cache = 400 tables
  Current table_definition_cache = 400 tables
  You have a total of 801 tables
  You have 400 open tables.
  Current table_cache hit rate is 16%
  , while 100% of your table cache is in use
  You should probably increase your table_cache
  You should probably increase your table_definition_cache value.
  </code></pre>
  
  <p>tried everything, any help?</p>
  
  <p>Thank you</p>