我开发了一个 PHP 和 MySQL Web 应用程序。最近它已经显示出放缓的迹象。我在 090516 上运行了 mysql-tuner，正常运行时间为 12 天。
服务器规格如下：
- Linux CentOS 6
- 48 个处理器
- 64GB RAM
这是 090516 的 mysql-tuner 日志输出，正常运行时间为 12 天：
root@layer1 [~/mysqltuner]# perl mysqltuner.pl --outputfile /~/mysqltuner/result_mysqltuner.txt
String found where operator expected at mysqltuner.pl line 3096, near
"get_wsrep_option 'gcache.mem_size'" (#1)
(S syntax) The Perl lexer knows whether to expect a term or an operator.
If it sees what it knows to be a term when it was expecting to see an
operator, it gives you this warning. Usually it indicates that an
operator or delimiter was omitted, such as a semicolon.
(Do you need to predeclare get_wsrep_option?)
Use of implicit split to @_ is deprecated at mysqltuner.pl line 3179 (#2)
(D deprecated, W syntax) It makes a lot of work for the compiler when you
clobber a subroutine's argument list, so it's better if you assign the results
of a split() explicitly to an array (or list).
>> MySQLTuner 1.6.10 - 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
[OK] Currently running supported MySQL version 5.6.31-log
[OK] Operating on 64-bit architecture
-------- Storage Engine Statistics -----------------------------------------------------------------
[--] Status: +ARCHIVE +BLACKHOLE +CSV -FEDERATED +InnoDB +MEMORY +MRG_MYISAM +MyISAM +PERFORMANCE_SCHEMA
[--] Data in MyISAM tables: 913M (Tables: 11)
[--] Data in InnoDB tables: 12M (Tables: 63)
[!!] Total fragmented tables: 11
-------- Security Recommendations ------------------------------------------------------------------
[OK] There are no anonymous accounts for any database users
[OK] All database users have passwords assigned
[!!] User 'munin@localhost' has user name as password.
[--] There are 605 basic passwords in the list.
-------- CVE Security Recommendations --------------------------------------------------------------
[OK] NO SECURITY CVE FOUND FOR YOUR VERSION
Argument "gcache.mem_size" isn't numeric in addition (+) at mysqltuner.pl line
1965 (#3)
(W numeric) The indicated string was fed as an argument to an operator
that expected a numeric value instead. If you're fortunate the message
will identify which operator was so unfortunate.
Argument "gcache.mem_size" isn't numeric in addition (+) at mysqltuner.pl line
1972 (#3)
-------- Performance Metrics -----------------------------------------------------------------------
[--] Up for: 12d 6h 21m 24s (2 q [0.000 qps], 1M conn, TX: 192B, RX: 240B)
[--] Reads / Writes: 100% / 0%
[--] Binary logging is disabled
[--] Physical Memory : 62.8G
[--] Max MySQL memory : 338.9M
[--] Other process memory: 505.0M
[--] Total buffers: 169.0M global + 1.1M per thread (151 max threads)
[--] P_S Max memory usage: 0B
Argument "*main::get_wsrep_option" isn't numeric in numeric ge (>=) at
mysqltuner.pl line 285 (#3)
Argument "*main::get_wsrep_option" isn't numeric in numeric ge (>=) at
mysqltuner.pl line 288 (#3)
Argument "*main::get_wsrep_option" isn't numeric in numeric ge (>=) at
mysqltuner.pl line 291 (#3)
[--] Galera GCache Max memory usage: *main::get_wsrep_optionB
[OK] Maximum reached memory usage: 340.0M (0.53% of installed RAM)
[OK] Maximum possible memory usage: 338.9M (0.53% of installed RAM)
[OK] Overall possible memory usage with other process is compatible with memory available
[OK] Slow queries: 0% (0/2)
[!!] Highest connection usage: 100% (152/151)
[OK] Aborted connections: 0.00% (34/1098331)
[OK] Query cache is disabled by default due to mutex contention.
[OK] No Sort requiring temporary tables
[OK] No joins without indexes
[OK] No tmp tables created on disk
[OK] Thread cache hit rate: 98% (17K created / 1M connections)
[OK] Table cache hit rate: 100% (381 open / 0 opened)
[OK] Open file limit used: 2% (228/10K)
[!!] Table locks acquired immediately: 94%
-------- ThreadPool Metrics ------------------------------------------------------------------------
[--] ThreadPool stat is disabled.
-------- Performance schema ------------------------------------------------------------------------
[--] Performance schema is disabled.
[--] Memory used by P_S: 0B
-------- MyISAM Metrics ----------------------------------------------------------------------------
[OK] Key buffer used: 100.0% (8M used / 8M cache)
[!!] Key buffer size / total MyISAM indexes: 8.0M/147.7M
[!!] Read Key buffer hit rate: 87.6% (16M cached / 1M reads)
[!!] Write Key buffer hit rate: 56.8% (1M cached / 777K writes)
-------- AriaDB Metrics ----------------------------------------------------------------------------
[--] AriaDB is disabled.
-------- InnoDB Metrics ----------------------------------------------------------------------------
[--] InnoDB is enabled.
[OK] InnoDB buffer pool / data size: 128.0M/12.1M
[!!] InnoDB buffer pool <= 1G and innodb_buffer_pool_instances(!=1).
[!!] InnoDB Used buffer: 17.82% (1460 used/ 8192 total)
[OK] InnoDB Read buffer efficiency: 100.00% (290756388 hits/ 290757478 total)
[!!] InnoDB Write Log efficiency: 12.12% (3691 hits/ 30446 total)
[OK] InnoDB log waits: 0.00% (0 waits / 34137 writes)
-------- TokuDB Metrics ----------------------------------------------------------------------------
[--] TokuDB is disabled.
-------- Galera Metrics ----------------------------------------------------------------------------
[--] Galera is disabled.
-------- Replication Metrics -----------------------------------------------------------------------
[--] Galera Synchronous replication: NO
[--] No replication slave(s) for this server.
[--] This is a standalone server.
-------- Recommendations ---------------------------------------------------------------------------
General recommendations:
Run OPTIMIZE TABLE to defragment tables for better performance
Set up a Secure Password for user@host ( SET PASSWORD FOR 'user'@'SpecificDNSorIp' = PASSWORD('secure_password'); )
Reduce or eliminate persistent connections to reduce connection usage
Optimize queries and/or use InnoDB to reduce lock wait
Variables to adjust:
max_connections (> 151)
wait_timeout (< 28800)
interactive_timeout (< 28800)
key_buffer_size (> 147.7M)
innodb_buffer_pool_instances (=1)
我很少有事情发生，但是我不是经验丰富的 MySQL DBA，因此正在向堆栈社区寻求建议。请告知我应该在 my.cnf 中修改哪些设置，如果我需要在 PHPMYADMIN 中对表进行碎片整理，是否需要在非工作时间进行。
直到最近我才注意到我的网络应用程序变慢了，最近我确实在内核更新后重新启动了服务器。截至这篇文章的当前正常运行时间为 19 小时。
**额外信息：** Web 应用程序有一个用户使用移动设备登录的前端，以及一个由办公室员工管理提交（即表单）并将它们发送到不同部门的后端。
如果需要，我可以用 munin 图表更新它。我知道服务器严重过度配置（这意味着它的 RAM 和处理器比需要的多，但我希望在未来拥有更多的东西）。我的问题是，我可以简单地调整一些 my.cnf 设置（如 mysqltuner 和/或 phpmyadmin 所建议的那样）以提高效率吗？