【发布时间】：2009-11-23 22:58:48
【问题描述】：
我的服务器 mysql 有一个大问题。一切都很好，但自从一周以来，它非常缓慢。 每个查询都很慢（有时超过 20 秒）。 我的配置没有任何改变。
谁能帮我知道为什么我的服务器现在变慢了？
谢谢。
这是我的 my.cnf：
[
mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
#
# * Basic Settings
#
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
language = /usr/share/mysql/english
#join_buffer_size = 128.0K
skip-external-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address = 127.0.0.1
# * Fine Tuning
#
key_buffer = 16M
max_allowed_packet = 16M
max_heap_table_size = 64M
tmp_table_size = 64M
thread_stack = 128K
thread_cache_size = 8
#max_connections = 100
table_cache = 400
join_buffer_size = 2000K
#thread_concurrency = 10
#
# * Query Cache Configuration
#
query_cache_limit = 1M
query_cache_size = 16M
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
#log = /var/log/mysql/mysql.log
#
# Error logging goes to syslog. This is a Debian improvement :)
#
# Here you can see queries with especially long duration
log_slow_queries = /var/log/mysql/mysql-slow.log
long_query_time = 2
#log-queries-not-using-indexes
#
# The following can be used as easy to replay backup logs or for replication.
#server-id = 1
log_bin = /var/log/mysql/mysql-bin.log
# WARNING: Using expire_logs_days without bin_log crashes the server! See README.Debian!
expire_logs_days = 10
max_binlog_size = 100M
#binlog_do_db = include_database_name
#binlog_ignore_db = include_database_name
#
# * BerkeleyDB
#
# Using BerkeleyDB is now discouraged as its support will cease in 5.1.12.
skip-bdb
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!
# You might want to disable InnoDB to shrink the mysqld process by circa 100MB.
#skip-innodb
innodb_buffer_pool_size = 42M
#
# * Security Features
#
# Read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# For generating SSL certificates I recommend the OpenSSL GUI "tinyca".
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem
[mysqldump]
quick
quote-names
max_allowed_packet = 16M
[mysql]
#no-auto-rehash # faster start of mysql but no tab completition
[isamchk]
key_buffer = 16M
【问题讨论】：
-
您使用的确切查询和表架构是什么？表中有多少行？
-
发布查询，并在您的查询上发布 EXPLAIN 的输出。可能 - 当您将更多数据倒入表中时，mysql 切换到使用错误的索引，并且/或者您没有正确的索引。
-
看起来
_run_faster = 1变量没有在 my.cnf 中设置。 （我开玩笑，我开玩笑。）
标签： mysql