Здравствуйте. Нужна помощь по устранение тормозов MySQL.
Имеется VDS (KVM) сервер с 768 mb RAM и 2x2.80 GHz CPU. Стоит связка nginx + php-fpm (с xcache). Страницы сайта грузятся быстро, но примерно раз в каждые ~20 начинаются дикие тормоза - страница может генерироваться от 2-х до 17 сек (в среднем - 3 сек). По логам удалось выяснить причину тормозов - это mysql. Сначала предполагал, что проблема в долгом подключении в БД, но включив slow log MySQL'а, оказалось, что тормозит сам сервер БД. В логе фигурируют различные запросы: select, insert, update, delete.
Баз у меня немного, размер не более 100 МБ. Сервер на ОС Debian 6.
mysql status:
Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Server version 5.5.31-1~dotdeb.0-log
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/run/mysqld/mysqld.sock
Uptime: 11 min 47 sec
Threads: 2 Questions: 15008 Slow queries: 24 Opens: 3789 Flush tables: 1 Open tables: 64 Queries per second avg: 21.227.
Оперативной памяти тоже хватает:
total used free shared buffers cached
Mem: 747 661 85 0 25 393
-/+ buffers/cache: 243 503
Swap: 0 0 0
my.cnf:
#
# The MySQL database server configuration file.
#
# You can copy this to one of:
# - "/etc/mysql/my.cnf" to set global options,
# - "~/.my.cnf" to set user-specific options.
#
# One can use all long options that the program supports.
# Run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# For explanations see
# http://dev.mysql.com/doc/mysql/en/server-system-variables.html
# This will be passed to all mysql clients
# It has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain "#" chars...
# Remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
# Here is entries for some specific programs
# The following values assume you have at least 16M ram
# This was formally known as [safe_mysqld]. Both versions are currently parsed.
[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
# lc-message-dir is unknown to MySQL 5.1
#lc-messages-dir = /usr/share/mysql
skip-name-resolve
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#
# * Fine Tuning
#
key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover = BACKUP
max_connections = 50
table_cache = 64
thread_concurrency = 10
#
# * Query Cache Configuration
#
query_cache_limit = 2M
query_cache_size = 4M
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
# As of 5.1 you can enable the log at runtime!
#general_log_file = /var/log/mysql/mysql.log
#general_log = 1
#
# Error logging goes to syslog due to /etc/mysql/conf.d/mysqld_safe_syslog.cnf.
#
# Here you can see queries with especially long duration
slow_query_log = 1
slow_query_log_file = /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.
# note: if you are setting up a replication slave, see README.Debian about
# other settings you may need to change.
#server-id = 1
#log_bin = /var/log/mysql/mysql-bin.log
expire_logs_days = 10
max_binlog_size = 100M
#binlog_do_db = include_database_name
#binlog_ignore_db = include_database_name
#
# * 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!
#
# * 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
#
# * IMPORTANT: Additional settings that can override those from this file!
# The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/
Простой
