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Help With mysqltuner Output
Posted by: Ifechukwukwu Okobi
Date: January 14, 2013 05:33AM

Hi All,

I have been assigned the task of making use of mysqltuner script to optimize the company's databases.

Below is the output of the script.

Will greatly appreciate help in understanding the output and how to go about fixing them effectively.



>> MySQLTuner 1.2.0 - Major Hayden <>
>> Bug reports, feature requests, and downloads at
>> Run with '--help' for additional options and output filtering

-------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.0.77-log
[OK] Operating on 64-bit architecture

-------- Storage Engine Statistics -------------------------------------------
[--] Status: -Archive +BDB -Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 235G (Tables: 357)
[--] Data in InnoDB tables: 66G (Tables: 52)
[!!] BDB is enabled but isn't being used
[!!] Total fragmented tables: 12

-------- Security Recommendations -------------------------------------------
[!!] User 'test@' has no password set.
[!!] User 'test2@' has no password set.
[!!] User 'test3@' has no password set.

-------- Performance Metrics -------------------------------------------------
[--] Up for: 612d 9h 45m 59s (7B q [142.169 qps], 10M conn, TX: 13197B, RX: 5191B)
[--] Reads / Writes: 52% / 48%
[--] Total buffers: 14.2G global + 11.2M per thread (1000 max threads)
[!!] Maximum possible memory usage: 25.2G (107% of installed RAM)
[OK] Slow queries: 0% (808K/7B)
[!!] Highest connection usage: 100% (1001/1000)
[OK] Key buffer size / total MyISAM indexes: 64.0M/39.3G
[OK] Key buffer hit rate: 98.8% (310B cached / 3B reads)
[!!] Query cache efficiency: 0.0% (680K cached / 2B selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 1% (1K temp sorts / 98K sorts)
[OK] Temporary tables created on disk: 0% (35K on disk / 410M total)
[OK] Thread cache hit rate: 98% (177K created / 10M connections)
[!!] Table cache hit rate: 0% (547 open / 298K opened)
[OK] Open file limit used: 0% (627/65K)
[OK] Table locks acquired immediately: 99% (10B immediate / 10B locks)
[!!] Connections aborted: 12%
[!!] InnoDB data size / buffer pool: 66.1G/14.0G

-------- Recommendations -----------------------------------------------------
General recommendations:
Add skip-bdb to MySQL configuration to disable BDB
Run OPTIMIZE TABLE to defragment tables for better performance
Reduce your overall MySQL memory footprint for system stability
Enable the slow query log to troubleshoot bad queries
Reduce or eliminate persistent connections to reduce connection usage
Increase table_cache gradually to avoid file descriptor limits
Your applications are not closing MySQL connections properly
Variables to adjust:
*** MySQL's maximum memory usage is dangerously high ***
*** Add RAM before increasing MySQL buffer variables ***
max_connections (> 1000)
wait_timeout (< 86400)
interactive_timeout (< 600)
query_cache_limit (> 1M, or use smaller result sets)
table_cache (> 2048)
innodb_buffer_pool_size (>= 66G)


Edited 1 time(s). Last edit at 01/16/2013 08:52AM by Ifechukwukwu Okobi.

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Written By
Help With mysqltuner Output
January 14, 2013 05:33AM
January 15, 2013 08:50AM
January 15, 2013 09:03AM
January 16, 2013 07:41PM
January 19, 2013 12:18AM

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