阿里云512M主机(CentOS 6.5)编译安装MySQL 5.6.21遇到的问题

运行mysql出现错误：

The server quit without updating PID file ...

原因：

内存太小

解决办法1：

使用下面my.cnf

# Example MySQL config file for small systems.

#

# This is for a system with little memory (<= 64M) where MySQL is only used

# from time to time and it's important that the mysqld daemon

# doesn't use much resources.

# MySQL programs look for option files in a set of

# locations which depend on the deployment platform.

# You can copy this option file to one of those

# locations. For information about these locations, see:

# http://dev.mysql.com/doc/mysql/en/option-files.html

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

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

# with the "--help" option.

# The following options will be passed to all MySQL clients

[client]

#password = your_password

#port    = @MYSQL_TCP_PORT@

#socket    = @MYSQL_UNIX_ADDR@

# Here follows entries for some specific programs

# The MySQL server

[mysqld]

port    = 3306

socket    = /tmp/mysql.sock

skip-external-locking

key_buffer_size = 16K

max_allowed_packet = 1M

table_open_cache = 4

sort_buffer_size = 64K

read_buffer_size = 256K

read_rnd_buffer_size = 256K

net_buffer_length = 2K

thread_stack = 128K

basedir=/usr/local/mysql

datadir=/usr/local/mysql/data

# Don't listen on a TCP/IP port at all. This can be a security enhancement,

# if all processes that need to connect to mysqld run on the same host.

# All interaction with mysqld must be made via Unix sockets or named pipes.

# Note that using this option without enabling named pipes on Windows

# (using the "enable-named-pipe" option) will render mysqld useless!

#skip-networking

server-id = 1

# Uncomment the following if you want to log updates

#log-bin=mysql-bin

# binary logging format - mixed recommended

#binlog_format=mixed

# Causes updates to non-transactional engines using statement format to be

# written directly to binary log. Before using this option make sure that

# there are no dependencies between transactional and non-transactional

# tables such as in the statement INSERT INTO t_myisam SELECT * FROM

# t_innodb; otherwise, slaves may diverge from the master.

#binlog_direct_non_transactional_updates=TRUE

# Uncomment the following if you are using InnoDB tables

#innodb_data_home_dir = @localstatedir@

#innodb_data_file_path = ibdata1:10M:autoextend

#innodb_log_group_home_dir = @localstatedir@

# You can set .._buffer_pool_size up to 50 - 80 %

# of RAM but beware of setting memory usage too high

#innodb_buffer_pool_size = 16M

#innodb_additional_mem_pool_size = 2M

# Set .._log_file_size to 25 % of buffer pool size

#innodb_log_file_size = 5M

#innodb_log_buffer_size = 8M

#innodb_flush_log_at_trx_commit = 1

#innodb_lock_wait_timeout = 50

[mysqldump]

quick

max_allowed_packet = 16M

[mysql]

no-auto-rehash

# Remove the next comment character if you are not familiar with SQL

#safe-updates

[myisamchk]

key_buffer_size = 8M

sort_buffer_size = 8M

[mysqlhotcopy]

interactive-timeout

即使使用方法1解决了不能启动的问题，mysql还是会偶尔因为内存不足而down掉。

解决办法2：

阿里云的主机 不是默认自带swap的 ，增加swap，可以缓解实际内存小的问题，当然性能不如实际物理内存好，但起码不会出现mysql不能启动，或者down掉的情况。增加swap的方法：

1.进入目录 欢迎访问，鄙视采集！

cd /var/ http://www.zrblog.net

2.获取要增加的SWAP文件块(这里以1GB为例)

dd if=/dev/zero of=swapfile bs=1024 count=1038336 欢迎访问，鄙视采集！

 3.创建SWAP文件

/sbin/mkswap swapfile

 4.激活SWAP文件

/sbin/swapon swapfile

 5.查看SWAP信息是否正确

/sbin/swapon –s

 6.添加到fstab文件中让系统引导时自动启动

echo "/var/swapfile swap swap defaults 0 0" >>/etc/fstab

上述2个方法仍然不能完全避免mysql偶尔down掉的情况。

本文转自 h2appy  51CTO博客，原文链接：http://blog.51cto.com/h2appy/1563984，如需转载请自行联系原作者