MySQL my.ini 性能调优 解决了性能的重大问题

最近数据库奇慢无比，一条语句需要19秒，并且把整个电脑的速度都拖慢了，还经常需要重启，一直找不到原因，终于在想到了my.ini的性能调优后，尝试了一下。解决了问题

记录如下：

2G内存,针对站多,抗压型的设置,最佳：

table_cache=1024 物理内存越大,设置就越大.默认为2402,调到512-1024最佳
innodb_additional_mem_pool_size=4M   默认为2M
innodb_flush_log_at_trx_commit=1(设置为0就是等到innodb_log_buffer_size列队满后再统一储存,默认为1)
innodb_log_buffer_size=2M             默认为1M
innodb_thread_concurrency=8       你的服务器CPU有几个就设置为几,建议用默认一般为8
key_buffer_size=256M                       默认为218       调到128最佳
tmp_table_size=64M                      默认为16M        调到64-256最挂
read_buffer_size=4M                       默认为64K
read_rnd_buffer_size=16M              默认为256K
sort_buffer_size=32M                   默认为256K
max_connections=1024                 默认为1210
thread_cache_size=120             默认为60
query_cache_size=64M

上面标注为红色的配置最重要，按照默认的来就完蛋了。

以下是当前配置

# MySQL Server Instance Configuration File


# ----------------------------------------------------------------------


# Generated by the MySQL Server Instance Configuration Wizard


#


#


# Installation Instructions


# ----------------------------------------------------------------------


#


# On Linux you can copy this file to /etc/my.cnf to set global options,


# mysql-data-dir/my.cnf to set server-specific options


# (@localstatedir@ for this installation) or to


# ~/.my.cnf to set user-specific options.


#


# On Windows you should keep this file in the installation directory


# of your server (e.g. C:\Program Files\MySQL\MySQL Server X.Y). To


# make sure the server reads the config file use the startup option


# "--defaults-file".


#


# To run run the server from the command line, execute this in a


# command line shell, e.g.


# mysqld --defaults-file="C:\Program Files\MySQL\MySQL Server X.Y\my.ini"


#


# To install the server as a Windows service manually, execute this in a


# command line shell, e.g.


# mysqld --install MySQLXY --defaults-file="C:\Program Files\MySQL\MySQL Server X.Y\my.ini"


#


# And then execute this in a command line shell to start the server, e.g.


# net start MySQLXY


#


#


# Guildlines for editing this file


# ----------------------------------------------------------------------


#


# In this file, you can use all long options that the program supports.


# If you want to know the options a program supports, start the program


# with the "--help" option.


#


# More detailed information about the individual options can also be


# found in the manual.


#


#


# CLIENT SECTION


# ----------------------------------------------------------------------


#


# The following options will be read by MySQL client applications.


# Note that only client applications shipped by MySQL are guaranteed


# to read this section. If you want your own MySQL client program to


# honor these values, you need to specify it as an option during the


# MySQL client library initialization.


#


[client]






port=3306






[mysql]






default-character-set=utf8










# SERVER SECTION


# ----------------------------------------------------------------------


#


# The following options will be read by the MySQL Server. Make sure that


# you have installed the server correctly (see above) so it reads this


# file.


#


[mysqld]






# The TCP/IP Port the MySQL Server will listen on


port=3306






log-slow-queries=D:/slow.log






# Try number of CPU's*2 for thread_concurrency


thread_concurrency=16






#Path to installation directory. All paths are usually resolved relative to this.


basedir="D:/MySQL/MySQL Server 5.0/"






#Path to the database root


datadir="E:/MySQL/data/"






# The default character set that will be used when a new schema or table is


# created and no character set is defined


default-character-set=utf8






# The default storage engine that will be used when create new tables when


default-storage-engine=INNODB






# Set the SQL mode to strict


sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"






# The maximum amount of concurrent sessions the MySQL server will


# allow. One of these connections will be reserved for a user with


# SUPER privileges to allow the administrator to login even if the


# connection limit has been reached.


max_connections=1024






# Query cache is used to cache SELECT results and later return them


# without actual executing the same query once again. Having the query


# cache enabled may result in significant speed improvements, if your


# have a lot of identical queries and rarely changing tables. See the


# "Qcache_lowmem_prunes" status variable to check if the current value


# is high enough for your load.


# Note: In case your tables change very often or if your queries are


# textually different every time, the query cache may result in a


# slowdown instead of a performance improvement.


query_cache_size=84M






# The number of open tables for all threads. Increasing this value


# increases the number of file descriptors that mysqld requires.


# Therefore you have to make sure to set the amount of open files


# allowed to at least 4096 in the variable "open-files-limit" in


# section [mysqld_safe]


table_cache=1024






# Maximum size for internal (in-memory) temporary tables. If a table


# grows larger than this value, it is automatically converted to disk


# based table This limitation is for a single table. There can be many


# of them.


tmp_table_size=64M










# How many threads we should keep in a cache for reuse. When a client


# disconnects, the client's threads are put in the cache if there aren't


# more than thread_cache_size threads from before.  This greatly reduces


# the amount of thread creations needed if you have a lot of new


# connections. (Normally this doesn't give a notable performance


# improvement if you have a good thread implementation.)


thread_cache_size=120






#*** MyISAM Specific options






# The maximum size of the temporary file MySQL is allowed to use while


# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.


# If the file-size would be bigger than this, the index will be created


# through the key cache (which is slower).


myisam_max_sort_file_size=100G






# If the temporary file used for fast index creation would be bigger


# than using the key cache by the amount specified here, then prefer the


# key cache method.  This is mainly used to force long character keys in


# large tables to use the slower key cache method to create the index.


myisam_max_extra_sort_file_size=100G






# If the temporary file used for fast index creation would be bigger


# than using the key cache by the amount specified here, then prefer the


# key cache method.  This is mainly used to force long character keys in


# large tables to use the slower key cache method to create the index.


myisam_sort_buffer_size=30M






# Size of the Key Buffer, used to cache index blocks for MyISAM tables.


# Do not set it larger than 30% of your available memory, as some memory


# is also required by the OS to cache rows. Even if you're not using


# MyISAM tables, you should still set it to 8-64M as it will also be


# used for internal temporary disk tables.


key_buffer_size=128M






# Size of the buffer used for doing full table scans of MyISAM tables.


# Allocated per thread, if a full scan is needed.


read_buffer_size=4M


read_rnd_buffer_size=16M






# This buffer is allocated when MySQL needs to rebuild the index in


# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE


# into an empty table. It is allocated per thread so be careful with


# large settings.


sort_buffer_size=32M










#*** INNODB Specific options ***


innodb_data_home_dir="E:/MySQL Datafiles/"






# Use this option if you have a MySQL server with InnoDB support enabled


# but you do not plan to use it. This will save memory and disk space


# and speed up some things.


#skip-innodb






# Additional memory pool that is used by InnoDB to store metadata


# information.  If InnoDB requires more memory for this purpose it will


# start to allocate it from the OS.  As this is fast enough on most


# recent operating systems, you normally do not need to change this


# value. SHOW INNODB STATUS will display the current amount used.


innodb_additional_mem_pool_size=4M






# If set to 1, InnoDB will flush (fsync) the transaction logs to the


# disk at each commit, which offers full ACID behavior. If you are


# willing to compromise this safety, and you are running small


# transactions, you may set this to 0 or 2 to reduce disk I/O to the


# logs. Value 0 means that the log is only written to the log file and


# the log file flushed to disk approximately once per second. Value 2


# means the log is written to the log file at each commit, but the log


# file is only flushed to disk approximately once per second.


innodb_flush_log_at_trx_commit=1






# The size of the buffer InnoDB uses for buffering log data. As soon as


# it is full, InnoDB will have to flush it to disk. As it is flushed


# once per second anyway, it does not make sense to have it very large


# (even with long transactions).


innodb_log_buffer_size=3M






# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and


# row data. The bigger you set this the less disk I/O is needed to


# access data in tables. On a dedicated database server you may set this


# parameter up to 80% of the machine physical memory size. Do not set it


# too large, though, because competition of the physical memory may


# cause paging in the operating system.  Note that on 32bit systems you


# might be limited to 2-3.5G of user level memory per process, so do not


# set it too high.


innodb_buffer_pool_size=250M






# Size of each log file in a log group. You should set the combined size


# of log files to about 25%-100% of your buffer pool size to avoid


# unneeded buffer pool flush activity on log file overwrite. However,


# note that a larger logfile size will increase the time needed for the


# recovery process.


innodb_log_file_size=50M






# Number of threads allowed inside the InnoDB kernel. The optimal value


# depends highly on the application, hardware as well as the OS


# scheduler properties. A too high value may lead to thread thrashing.


innodb_thread_concurrency=8


local-infile=0
skip-show-database
skip-symbolic-links


skip-name-resolve


max_allowed_packet=24M