我的网络服务器使用专用主机：
Intel(R) Xeon(R) CPU E5620 8core
12Gram
Centos32bit/Driectadmin
DISK SAS 80G
Php-cgi
此主机正在运行一个网站
Use wordpress 2.92(+plugin cache...)
Database size 600MB
only 100online
我的网站运行非常慢。请帮我配置 my.cnf。
[mysqld]
user=mysql
key_buffer=128M
set-variable = max_connections=1000
socket = /var/lib/mysql/mysql.sock
key_buffer =32M
table_cache = 1024
open_files_limit = 16344
join_buffer_size = 8M
read_buffer_size = 8M
sort_buffer_size = 8M
tmp_table_size=512M
read_rnd_buffer_size=8M
max_heap_table_size=256M
#myisam_sort_buffer_size=256M
thread_cache_size=8
thread_cache=32
query_cache_type=1
query_cache_limit=1024M
query_cache_size=1024M
thread_concurrency = 16
wait_timeout = 10
connect_timeout = 10
interactive_timeout = 10
long_query_time=1
log-slow-queries = /var/log/mysqlslowqueries.log
max_allowed_packet=32M
skip-innodb
[myisamchk]
key_buffer = 64M
sort_buffer = 64M
read_buffer = 16M
write_buffer = 16M
[isamchk]
key_buffer=64M
sort_buffer=64M
read_buffer=16M
write_buffer=16M
和 MySQLTuner
-------- General Statistics --------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.1.47-log
[!!] 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: 471M (Tables: 30)
[!!] Total fragmented tables: 2
-------- Performance Metrics -------------------------------------------------
[--] Up for: 1d 6h 39m 2s (6M q [57.776 qps], 60K conn, TX: 999M, RX: 2B)
[--] Reads / Writes: 93% / 7%
[--] Total buffers: 1.3G global + 32.2M per thread (1000 max threads)
[!!] Allocating > 2GB RAM on 32-bit systems can cause system instability
[!!] Maximum possible memory usage: 32.7G (275% of installed RAM)
[OK] Slow queries: 0% (10K/6M)
[OK] Highest usage of available connections: 5% (52/1000)
[OK] Key buffer size / total MyISAM indexes: 32.0M/65.5M
[OK] Key buffer hit rate: 100.0% (938M cached / 108K reads)
[OK] Query cache efficiency: 51.4% (3M cached / 5M selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (929 temp sorts / 2M sorts)
[!!] Temporary tables created on disk: 49% (2M on disk / 4M total)
[OK] Thread cache hit rate: 99% (580 created / 60K connections)
[OK] Table cache hit rate: 97% (281 open / 288 opened)
[OK] Open file limit used: 1% (319/16K)
[OK] Table locks acquired immediately: 99% (7M immediate / 7M locks)
-------- Recommendations -----------------------------------------------------
General recommendations:
Run OPTIMIZE TABLE to defragment tables for better performance
Temporary table size is already large - reduce result set size
Reduce your SELECT DISTINCT queries without LIMIT clauses
无法运行 mysqld
[root@server ~]#
[root@server ~]# mysqld
100607 18:21:17 [Warning] mysqld: Option '--set-variable' is deprecated. Use --
100607 18:21:17 [Warning] '--log_slow_queries' is deprecated and will be remove
100607 18:21:17 [Note] Plugin 'FEDERATED' is disabled.
100607 18:21:17 [Note] Plugin 'InnoDB' is disabled.
mysqld: File '/var/log/mysqlslowqueries.log' not found (Errcode: 13)
100607 18:21:17 [ERROR] Could not use /var/log/mysqlslowqueries.log for logging urn it on again: fix the cause, shutdown the MySQL server and restart it.
100607 18:21:17 [ERROR] Can't start server: Bind on TCP/IP port: Address alread
100607 18:21:17 [ERROR] Do you already have another mysqld server running on po
100607 18:21:17 [ERROR] Aborting
100607 18:21:17 [Note] mysqld: Shutdown complete
并从顶部输出
[root@server ~]#顶部
top - 18:45:03 up 3 days, 4:40, 1 user, load average: 1.80, 1.42, 1.40
Tasks: 266 total, 1 running, 265 sleeping, 0 stopped, 0 zombie
Cpu(s): 4.6%us, 2.5%sy, 0.0%ni, 92.9%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 12462096k total, 2741388k used, 9720708k free, 599584k buffers
Swap: 8385920k total, 0k used, 8385920k free, 1612488k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
7487 mysql 15 0 1138m 241m 3572 S 98.7 2.0 811:12.72 mysqld
1508 admin 16 0 166m 43m 21m S 0.3 0.4 0:00.80 php-cgi
2019 apache 15 0 9264 3268 1444 S 0.3 0.0 0:00.06 httpd
2089 root 15 0 2336 1132 800 R 0.3 0.0 0:00.15 top
32137 admin 15 0 173m 51m 22m S 0.3 0.4 0:02.11 php-cgi
1 root 15 0 2072 580 504 S 0.0 0.0 0:02.42 init
2 root RT -5 0 0 0 S 0.0 0.0 0:00.06 migration/0
3 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0
4 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/0
5 root RT -5 0 0 0 S 0.0 0.0 0:00.03 migration/1
6 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/1
7 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/1
8 root RT -5 0 0 0 S 0.0 0.0 0:00.18 migration/2
9 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/2
10 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/2
11 root RT -5 0 0 0 S 0.0 0.0 0:00.02 migration/3
12 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/3
13 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/3
14 root RT -5 0 0 0 S 0.0 0.0 0:00.01 migration/4
15 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/4
16 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/4
17 root RT -5 0 0 0 S 0.0 0.0 0:00.01 migration/5
18 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/5
19 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/5
20 root RT -5 0 0 0 S 0.0 0.0 0:00.01 migration/6
21 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/6
22 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/6
23 root RT -5 0 0 0 S 0.0 0.0 0:00.00 migration/7
24 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/7
25 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/7
26 root RT -5 0 0 0 S 0.0 0.0 0:00.05 migration/8
27 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/8
28 root RT -5 0 0 0 S 0.0 0.0 0:00.00 watchdog/8
29 root RT -5 0 0 0 S 0.0 0.0 0:00.05 migration/9
答案1
如果你不知道从哪里开始，那就从MySQLTuner。
你刚才下载并运行 perl 脚本。
它会询问 mysql 管理员的用户名和密码，然后列出一些常规统计信息、存储统计信息和性能指标，最后给您一份建议列表。
它节省了您对服务器实例进行初始审查的时间。
修复问题后，我建议每隔一小时左右运行一次脚本，持续一周（可能更少/可能更长时间，具体取决于数据库的繁忙程度），以查看实际运行后是否需要更改任何设置。
另请参阅类似这样的资源。
一旦你知道你的 MySQL 实例是正常的，你就需要优化应用程序代码中的特定查询，你可以通过检查慢查询日志（如果其中有任何内容）并使用类似以下的分析器来识别最严重的违规者调试。
答案2
您遇到的第一个问题是您正在运行 32 位操作系统。您有 12G 的 RAM（如果我没有看错的话），而且您永远不会看到 Mysql 使用那么多，因为您运行的是 32 位。将 Centos 升级到 64 位操作系统，然后开始使用他们提供的 my.large.cnf 文件。这应该会让您朝着更好的方向前进。如果您仍然遇到问题，那么需要评估的事情是主要是读取、写入还是两者兼有。这可以告诉您应该使用 Innodb 还是 MYISAM。Innodb 非常适合大量更新/写入和读取，如果所有内容主要是读取，那么 MyISAM 是一个不错的选择。我们还需要知道这一点，以帮助弄清楚 Key Cache 等。但第一件事是让操作系统使用所有 RAM。
答案3
show status
show variables
show processlist
您使用的是 php-cgi？fcgid 还是 fastcgi？
答案4
您是否查看过 mysql 内部正在运行的 MySQL 进程？（例如通过 mytop？）
MySQLd 进程的高 CPU 负载让我不寒而栗......