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MySQL /etc/my.cnf Help

Discussion in 'Workarounds and Optimization' started by wrender, Nov 14, 2012.

  1. wrender

    wrender Well-Known Member

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    Hello,

    I just upgraded my server to 48GB of ram in hopes of improving MySQL performance. The server has 15K RPM SAS drives, with a Raid 5 configuration. A XEON quad core 2.96GHz processor. Would anyone be able to make recommendations on how I could optimize MySQL to take advantage of the upgraded memory? I have been using the mysqltuner.pl and tuning-primer.sh scripts, but they basically just keep telling me to increase my tmp_table_size, max_heap_table_size and table_cache. I am concerned that I may be increasing these too much and there seems to be little documentation on tuning a server with this much memory.

    Here is my current configuration:

    Code:
    [mysqld_safe]
    log-error="/var/log/mysqld.log"
    pid-file="/var/run/mysqld/mysqld.pid"
    default-storage-engine=MyISAM
    innodb_file_per_table=1
    [mysqld]
    tmp_table_size=1024M
    max_heap_table_size=1024M
    query_cache_size=192M
    query_cache_limit=2M
    query_cache_type=1
    innodb_file_per_table=1
    max_allowed_packet=64M
    open-files-limit=80K
    innodb_buffer_pool_size=7000M
    innodb_log_buffer_size=4M
    innodb_flush_log_at_trx_commit = 2
    thread_cache_size=8
    thread_concurrency=8
    innodb_thread_concurrency = 16
    table_cache=12K
    table_definition_cache=18K
    key_buffer_size=64M
    join_buffer_size=4M
    low_priority_updates=1
    concurrent_insert=ALWAYS
    slow_query_log
    long_query_time=2
    
    Here is a current output from the tuning programs. Although the server has not been running for 48 hours, it was outputting the same information before when it had run for 48 hours.

    Code:
    ./mysqltuner.pl
    
     >>  MySQLTuner 1.2.0 - Major Hayden <major@mhtx.net>
     >>  Bug reports, feature requests, and downloads at http://mysqltuner.com/
     >>  Run with '--help' for additional options and output filtering
    
    -------- General Statistics --------------------------------------------------
    [--] Skipped version check for MySQLTuner script
    [OK] Currently running supported MySQL version 5.5.27-cll
    [OK] Operating on 64-bit architecture
    
    -------- Storage Engine Statistics -------------------------------------------
    [--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster
    [--] Data in MyISAM tables: 1G (Tables: 4520)
    [--] Data in InnoDB tables: 1G (Tables: 4653)
    [--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)
    [!!] Total fragmented tables: 381
    
    -------- Security Recommendations  -------------------------------------------
    [OK] All database users have passwords assigned
    
    -------- Performance Metrics -------------------------------------------------
    [--] Up for: 13m 6s (170K q [216.503 qps], 1K conn, TX: 982M, RX: 35M)
    [--] Reads / Writes: 62% / 38%
    [--] Total buffers: 8.1G global + 6.6M per thread (151 max threads)
    [OK] Maximum possible memory usage: 9.1G (19% of installed RAM)
    [OK] Slow queries: 0% (1/170K)
    [OK] Highest usage of available connections: 7% (11/151)
    [OK] Key buffer size / total MyISAM indexes: 64.0M/313.7M
    [OK] Key buffer hit rate: 99.5% (1M cached / 9K reads)
    [OK] Query cache efficiency: 82.7% (118K cached / 143K selects)
    [OK] Query cache prunes per day: 0
    [OK] Sorts requiring temporary tables: 0% (0 temp sorts / 2K sorts)
    [!!] Joins performed without indexes: 9
    [!!] Temporary tables created on disk: 35% (1K on disk / 3K total)
    [OK] Thread cache hit rate: 99% (11 created / 1K connections)
    [!!] Table cache hit rate: 0% (3 open / 18K opened)
    [OK] Open file limit used: 0% (7/81K)
    [OK] Table locks acquired immediately: 100% (46K immediate / 46K locks)
    [OK] InnoDB data size / buffer pool: 1.1G/6.8G
    
    -------- Recommendations -----------------------------------------------------
    General recommendations:
        Run OPTIMIZE TABLE to defragment tables for better performance
        MySQL started within last 24 hours - recommendations may be inaccurate
        Adjust your join queries to always utilize indexes
        Temporary table size is already large - reduce result set size
        Reduce your SELECT DISTINCT queries without LIMIT clauses
        Increase table_cache gradually to avoid file descriptor limits
    Variables to adjust:
        join_buffer_size (> 4.0M, or always use indexes with joins)
        table_cache (> 12288)
    
    And tuning-primer.sh results:

    Code:
    -- MYSQL PERFORMANCE TUNING PRIMER --
                 - By: Matthew Montgomery -
    
    MySQL Version 5.5.27-cll x86_64
    
    Uptime = 0 days 0 hrs 14 min 38 sec
    Avg. qps = 205
    Total Questions = 180106
    Threads Connected = 4
    
    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 enabled.
    Current long_query_time = 2.000000 sec.
    You have 1 out of 180127 that take longer than 2.000000 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 = 8
    Current threads_cached = 5
    Current threads_per_sec = 0
    Historic threads_per_sec = 0
    Your thread_cache_size is fine
    
    MAX CONNECTIONS
    Current max_connections = 151
    Current threads_connected = 5
    Historic max_used_connections = 11
    The number of used connections is 7% 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 = 724 M
    Current InnoDB data space = 1.07 G
    Current InnoDB buffer pool free = 85 %
    Current innodb_buffer_pool_size = 6.83 G
    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 : 7.16 G
    Configured Max Per-thread Buffers : 1000 M
    Configured Max Global Buffers : 7.09 G
    Configured Max Memory Limit : 8.07 G
    Physical Memory : 47.04 G
    Max memory limit seem to be within acceptable norms
    
    KEY BUFFER
    Current MyISAM index space = 313 M
    Current key_buffer_size = 64 M
    Key cache miss rate is 1 : 179
    Key buffer free ratio = 79 %
    Your key_buffer_size seems to be fine
    
    QUERY CACHE
    Query cache is enabled
    Current query_cache_size = 192 M
    Current query_cache_used = 13 M
    Current query_cache_limit = 2 M
    Current Query cache Memory fill ratio = 6.92 %
    Current query_cache_min_res_unit = 4 K
    Your query_cache_size seems to be too high.
    Perhaps you can use these resources elsewhere
    MySQL won't cache query results that are larger than query_cache_limit in size
    
    SORT OPERATIONS
    Current sort_buffer_size = 2 M
    Current read_rnd_buffer_size = 256 K
    Sort buffer seems to be fine
    
    JOINS
    Current join_buffer_size = 4.00 M
    You have had 9 queries where a join could not use an index properly
    join_buffer_size >= 4 M
    This is not advised
    You should enable "log-queries-not-using-indexes"
    Then look for non indexed joins in the slow query log.
    
    OPEN FILES LIMIT
    Current open_files_limit = 81920 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 = 12288 tables
    Current table_definition_cache = 18432 tables
    You have a total of 9214 tables
    You have 9218 open tables.
    The table_cache value seems to be fine
    
    TEMP TABLES
    Current max_heap_table_size = 1.00 G
    Current tmp_table_size = 1.00 G
    Of 2897 temp tables, 32% were created on disk
    Perhaps you should increase your tmp_table_size and/or max_heap_table_size
    to reduce the number of disk-based temporary tables
    Note! BLOB and TEXT columns are not allow in memory tables.
    If you are using these columns raising these values might not impact your
    ratio of on disk temp tables.
    
    TABLE SCANS
    Current read_buffer_size = 128 K
    Current table scan ratio = 19 : 1
    read_buffer_size seems to be fine
    
    TABLE LOCKING
    Current Lock Wait ratio = 0 : 180531
    Your table locking seems to be fine
    
     
  2. tank

    tank Well-Known Member

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    More RAM does not always meen better performance.

    1. Wait the 24 hours before running the tests, so that they are not inaccurate.
    2. Here is a video about this. MySQL OptimizationcPanel Videos | cPanel Videos
    3. MYSQL is a process in which you can commit more resources but at a certain point it wont help. If someone has a bad database, their is nothing you can do about it.
     
  3. cPanelJared

    cPanelJared Technical Analyst
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    As tank said, you need to run mysqltuner.pl, make the changes it suggests, restart MySQL, wait a full day, and run it again. MySQL optimization is a complex task and can be something of a moving target, so you will need to run mysqltuner.pl and adjust the MySQL configuration several times over the course of days or weeks until gradually MySQL is tweaked into a better configuration.

    Unfortunately, there is no simple one-step solution to instantly optimize MySQL for all your sites. Tuning it requires making observations, making changes based on those observations, and then making more observations. Like many facets of server administration, it can be a slow, tedious process, and bad database design or poor programming of scripts that access a database can significantly complicate the task.
     
  4. wrender

    wrender Well-Known Member

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    Thanks, but I already know these things. I was hoping that someone could make a suggestion based on the amount of tables, and physical resources I have. Even after waiting 48 hours, the tuning programs still always recommend turning up the tmp_table_size, max_heap_table_size and table_cache.
     
  5. wrender

    wrender Well-Known Member

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    Video was still very informative though. Thanks for posting that.
     
  6. tank

    tank Well-Known Member

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    I would say now post after 24 hours again, if you want recommendations. Yea i liked the video too. Maybe she can start a MySQL optimization business. :) LOL
     
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