【发布时间】：2011-04-14 18:54:38
【问题描述】：
在Serverfault上遇到这个问题几天没有运气。
我已经在 VPS 上运行了 mysqltuner.pl，并且对于要更改的变量的建议有很多问题。我敢肯定，这些都是具有复杂答案的一般性问题。
我没有足够的知识来编写查询并针对服务器进行测试，但我只是想从运行五个 WordPress 网站的服务器中获得更高的性能，每月浏览量 >200,000 次。
我已经通过 phpmyadmin 优化了数据库（并且经常这样做），但是调谐器仍然说有碎片表。而且因为这是 WordPress，所以我无法更改核心代码中的查询。
但是我应该将query_cache_size 和innodb_buffer_pool_size 等变量增加多少？其他 innodb 变量呢？
建议的一些变量在 my.cnf 中不存在，例如 table_cache，并且在调谐器报告中被标记等。我可以将它们添加到 my.cnf 中吗？
（为什么这个块在my.cnf中是重复的？我可以删除重复的吗？）
set-variable = innodb_buffer_pool_size=2M set-variable = innodb_additional_mem_pool_size=500K set-variable = innodb_log_buffer_size=500K set-variable = innodb_thread_concurrency=2
下面是my.cnf和mysqltuner的输出：
my.cnf 的内容：
query-cache-type = 1
query-cache-size = 8M
set-variable=local-infile=0
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
old_passwords=1
skip-bdb
set-variable = innodb_buffer_pool_size=2M
set-variable = innodb_additional_mem_pool_size=500K
set-variable = innodb_log_buffer_size=500K
set-variable = innodb_thread_concurrency=2
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
skip-bdb
set-variable = innodb_buffer_pool_size=2M
set-variable = innodb_additional_mem_pool_size=500K
set-variable = innodb_log_buffer_size=500K
set-variable = innodb_thread_concurrency=2
mysqltuner 的输出：
------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.0.45
[!!] Switch to 64-bit OS - MySQL cannot currently use all of your RAM
-------- Storage Engine Statistics -------------------------------------------
[--] Status: -Archive -BDB -Federated +InnoDB -ISAM -NDBCluster
[--] Data in MyISAM tables: 133M (Tables: 637)
[--] Data in InnoDB tables: 10M (Tables: 344)
[--] Data in MEMORY tables: 126K (Tables: 2)
[!!] Total fragmented tables: 69
-------- Security Recommendations -------------------------------------------
[OK] All database users have passwords assigned
-------- Performance Metrics -------------------------------------------------
[--] Up for: 1d 6h 24m 13s (2M q [22.135 qps], 116K conn, TX: 4B, RX: 530M)
[--] Reads / Writes: 97% / 3%
[--] Total buffers: 35.0M global + 2.7M per thread (100 max threads)
[OK] Maximum possible memory usage: 303.7M (8% of installed RAM)
[OK] Slow queries: 0% (4/2M)
[OK] Highest usage of available connections: 53% (53/100)
[OK] Key buffer size / total MyISAM indexes: 8.0M/46.1M
[OK] Key buffer hit rate: 99.6% (749M cached / 2M reads)
[OK] Query cache efficiency: 32.2% (685K cached / 2M selects)
[!!] Query cache prunes per day: 948863
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 660K sorts)
[!!] Temporary tables created on disk: 46% (400K on disk / 869K total)
[!!] Thread cache is disabled
[!!] Table cache hit rate: 0% (64 open / 24K opened)
[OK] Open file limit used: 10% (109/1K)
[OK] Table locks acquired immediately: 99% (2M immediate / 2M locks)
[!!] InnoDB data size / buffer pool: 10.6M/2.0M
-------- Recommendations -----------------------------------------------------
General recommendations:
Run OPTIMIZE TABLE to defragment tables for better performance
Enable the slow query log to troubleshoot bad queries
When making adjustments, make tmp_table_size/max_heap_table_size equal
Reduce your SELECT DISTINCT queries without LIMIT clauses
Set thread_cache_size to 4 as a starting value
Increase table_cache gradually to avoid file descriptor limits
Variables to adjust:
query_cache_size (> 8M)
tmp_table_size (> 32M)
max_heap_table_size (> 16M)
thread_cache_size (start at 4)
table_cache (> 64)
innodb_buffer_pool_size (>= 10M)
【问题讨论】：
标签： mysql performance wordpress