适用于大型系统的MySQL配置文件

Question

我们在Windows 2003 Server Enterpise Edition框中运行MySQL。 MySQL是关于盒子上运行的唯一程序。我们有约。 8个从站复制到它，但我的理解是，有多个从站连接到同一个主站不会显着减慢性能，如果有的话。主服务器具有16G RAM，10个RAID 10的Terabyte驱动器和4个双核处理器。从我从其他网站看到的，我们有一台非常强大的机器作为我们的主数据库服务器。我们只从一台只有4G内存的机器升级，但使用类似的硬盘，RAID等。它也运行Apache，所以它是我们的数据库服务器和我们的应用服务器。它变得有点慢，所以我们将db服务器拆分到这台新机器上，并将应用程序服务器保留在第一台机器上。我们还在其他一些从属服务器中分配了应用程序负载，这些服务器也运行该应用程序。问题是新的数据库服务器有几乎所有的时间都会消耗95-100％的CPU，导致应用程序运行缓慢。我知道我们有几个查询和表结构可以更好地优化，但是由于它们在较老的小型服务器上工作正常，我认为我们的my.ini（MySQL配置）文件没有正确配置。我在网上看到的大部分内容都是用于在小型机器上设置配置文件，所以任何人都可以帮助我正确地使用我们的大型专用机器的my.ini文件吗？我只是不明白mysqld如何陷入困境！

供参考：我们每秒约有100个查询。我们只使用MyISAM表，所以ini文件中设置了skip-innodb。是的，我知道它正在正确读取ini文件，因为我可以更改一些设置（如服务器ID，它会在启动时终止服务器）。

这里是my.ini文件：

#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=latin1 


# 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 


#Path to installation directory. All paths are usually resolved relative to this. 
basedir="D:/MySQL/" 

#Path to the database root 
datadir="D:/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=latin1 

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

# Set the SQL mode to strict 
#sql-mode="STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION" 
# we changed this because there are a couple of queries that can get blocked otherwise 
sql-mode="" 

#performance configs 
skip-locking 
max_allowed_packet = 1M 
table_open_cache = 512 

# 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=1510 

# 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=168M 

# 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=3020 

# 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=30M 


# 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=64 

#*** 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_sort_buffer_size=64M 

# 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=3072M 

# 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=2M 
read_rnd_buffer_size=8M 

# 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=2M 


#*** INNODB Specific options *** 
innodb_data_home_dir="D:/MySQL InnoDB 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=11M 

# 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=6M 

# 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=500M 

# 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=100M 

# 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=10 


#replication settings (this is the master) 
log-bin=log 
server-id = 1 

感谢所有帮助。非常感谢。

Answer 1

我在ServerFault上得到了一些很好的回应。原来主要的问题是新服务器上的磁盘I/O。 I/O远远低于旧的32位机器，因此我现在正在跟踪这个问题。谢谢。