Como ajustar nosso servidor MySQL?

8

O MySQL não é minha opção, mas preciso ajustar um dos nossos servidores.

Aqui estão os requisitos / especificações:

  • O servidor MySQL tem apenas um banco de dados significativo
  • Temos apenas um "tipo" de aplicativo conectado a ele, e não há muitas instâncias ao mesmo tempo conectadas a ele: no máximo 15. (esses aplicativos são bots XMPP)
  • Esse aplicativo tem um bloqueio sem bloqueio OI, o que significa que eles nunca "espera" no servidor de banco de dados e continue lidar com as solicitações recebidas enquanto as consultas do banco de dados estão sendo processadas. Isso implica que em algum momento uma instância desta aplicação pode ter vários (muito!) conexões com o banco de dados servidor (especialmente se algumas consultas forem lento)
    • Todas as consultas estão usando índices
    • Nossa máquina host só executa o MySQL. É uma instância do Xen (@slicehost) com 2 GB de RAM.
    • Usamos a tabela InnoDB porque precisamos de algumas transações básicas, mas provavelmente poderíamos mudar para o MyISAM se isso tivesse um impacto real no desempenho.

Como está configurado no momento, nosso servidor MySQL começa a comer lentamente toda a memória disponível (usamos collectd, aqui está um gráfico). Em algum momento (depois de alguns dias / semanas), ele pára de realizar consultas (ele parou esta noite por 2 horas, e eu tive que reiniciar o servidor MySQL: veja a segunda imagem):

(desculpe, novos usrs não podem postar imagens e apenas 1 hiperlink: /)

  • Semanalmente: link

  • Hoje: i31.tinypic.com/ir53yg.png

Aqui está o meu my.cnf atual

#
# The MySQL database server configuration file.
#
# 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 32M 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
#

#
# * IMPORTANT
#   If you make changes to these settings and your system uses apparmor, you may
#   also need to also adjust /etc/apparmor.d/usr.sbin.mysqld.
#

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
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.
# yann changed this on a friday balbla
#bind-address       = 127.0.0.1
bind-address        = 0.0.0.0
#
# * Fine Tuning
#
key_buffer      = 16M
max_allowed_packet  = 16M
thread_stack        = 128K
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        = 2000
#table_cache            = 64
#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 = 3
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
#
# * 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

# Fine tunig added by JG on 06/03 based on http://www.mysqlperformanceblog.com/2007/11/01/innodb-performance-optimization-basics/
innodb_buffer_pool_size  = 1G
#innodb_log_file_size     = 256M
innodb_log_buffer_size   = 4M
innodb_flush_log_at_trx_commit = 2
innodb_thread_concurrency      = 8
innodb_flush_method            = O_DIRECT
innodb_file_per_table
transaction-isolation          = READ-COMMITTED
innodb_table_locks             = 0         

#
# * Federated
#
# The FEDERATED storage engine is disabled since 5.0.67 by default in the .cnf files
# shipped with MySQL distributions (my-huge.cnf, my-medium.cnf, and so forth).
#
skip-federated
#
# * 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

#
# * NDB Cluster
#
# See /usr/share/doc/mysql-server-*/README.Debian for more information.
#
# The following configuration is read by the NDB Data Nodes (ndbd processes)
# not from the NDB Management Nodes (ndb_mgmd processes).
#
# [MYSQL_CLUSTER]
# ndb-connectstring=127.0.0.1


#
# * 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/

Aqui está um despejo de consultas lentas:

$ mysqldumpslow /var/log/mysql/mysql-slow.log

Reading mysql slow query log from /var/log/mysql/mysql-slow.log
Count: 5  Time=3689348814741910528.00s (-1s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  SET insert_id=N;
  INSERT IGNORE INTO 'feeds' ('url') VALUES ('S')

Count: 41  Time=1349761761490942720.00s (-1s)  Lock=0.12s (5s)  Rows=253.0 (10373), superfeeder[superfeeder]@localhost
  SHOW GLOBAL STATUS

Count: 25  Time=737869762948382080.00s (-1s)  Lock=0.00s (0s)  Rows=18.1 (452), superfeeder[superfeeder]@[172.21.1.158]
  SELECT 'feeds'.* FROM 'feeds' WHERE ('fetch_session_id' = 'S')

Count: 12952  Time=1424239042133230.25s (-1s)  Lock=0.00s (1s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  SET insert_id=N;
  INSERT IGNORE INTO 'entries' ('chunks', 'time', 'feed_id', 'unique_id', 'link', 'chunk') VALUES ('S', 'S', N, 'S', 'S', 'S')

Count: 29  Time=656.55s (19040s)  Lock=5.28s (153s)  Rows=0.8 (23), superfeeder[superfeeder]@[172.21.1.175]
  select salt,crypted_password from users where login='S'

Count: 39  Time=505.23s (19704s)  Lock=2.41s (94s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  DELETE FROM 'feeds' WHERE (url LIKE 'S')

Count: 2275  Time=502.50s (1143184s)  Lock=3.48s (7922s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'next_fetch' = 'S', 'fetch_session_id' = 'S' WHERE ('next_fetch' < 'S') LIMIT N

Count: 1  Time=443.00s (443s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'next_fetch' = 'S' WHERE ('feeds'.'url' IN (NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL))

Count: 14  Time=289.43s (4052s)  Lock=0.71s (10s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'next_fetch' = 'S' WHERE ('feeds'.'url' IN ('S','S'))

Count: 2  Time=256.00s (512s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'next_fetch' = 'S' WHERE ('feeds'.'url' IN (NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL))

Count: 1  Time=237.00s (237s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'next_fetch' = 'S' WHERE ('feeds'.'url' IN ('S'))

Count: 24  Time=191.58s (4598s)  Lock=1.12s (27s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'next_fetch' = 'S' WHERE ('feeds'.'id' = 'S')

Count: 5  Time=144.20s (721s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'next_fetch' = 'S' WHERE ('feeds'.'url' IN (NULL,NULL,NULL))

Count: 1  Time=101.00s (101s)  Lock=1.00s (1s)  Rows=1.0 (1), superfeeder[superfeeder]@[172.21.1.158]
  SELECT * FROM 'users' WHERE ('login' = 'S') LIMIT N

Count: 79  Time=35.51s (2805s)  Lock=2.52s (199s)  Rows=0.2 (12), superfeeder[superfeeder]@[172.21.1.184]
  SELECT 'feeds'.id FROM 'feeds' WHERE ('feeds'.'url' = BINARY 'S' AND 'feeds'.id <> N)  LIMIT N

Count: 1  Time=28.00s (28s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  UPDATE 'feeds' SET 'last_maintenance_at' = 'S', 'updated_at' = 'S' WHERE 'id' = N

Count: 51  Time=23.51s (1199s)  Lock=0.12s (6s)  Rows=19.2 (981), superfeeder[superfeeder]@2hosts
  SELECT version FROM schema_migrations

Count: 5  Time=20.60s (103s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  BEGIN

Count: 65  Time=15.86s (1031s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = 'S', 'last_sup_update_id' = NULL, 'updated_at' = 'S', 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = 'S', 'active' = 'S', 'last_fetch' = 'S', 'created_at' = 'S', 'max_period' = 'S' WHERE ('id' = N)

Count: 23  Time=11.52s (265s)  Lock=0.00s (0s)  Rows=231.0 (5313), superfeeder[superfeeder]@2hosts
  #

Count: 132  Time=10.53s (1390s)  Lock=0.02s (2s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = 'S', 'last_sup_update_id' = NULL, 'updated_at' = 'S', 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = 'S', 'active' = 'S', 'last_fetch' = 'S', 'created_at' = NULL, 'max_period' = 'S' WHERE ('id' = N)

Count: 62  Time=9.81s (608s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.184]
  ROLLBACK

Count: 151  Time=8.94s (1350s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@2hosts
  DELETE FROM 'entries' WHERE ('time' < 'S')

Count: 25  Time=8.76s (219s)  Lock=0.00s (0s)  Rows=1.0 (24), superfeeder[superfeeder]@[172.21.1.158]
  SELECT * FROM 'feeds' WHERE ('url' = 'S') LIMIT N

Count: 2  Time=8.50s (17s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  set SQL_AUTO_IS_NULL=N

Count: 8802  Time=8.44s (74319s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  INSERT IGNORE INTO 'entries' ('chunks', 'time', 'feed_id', 'unique_id', 'link', 'chunk') VALUES ('S', 'S', N, 'S', 'S', 'S')

Count: 1  Time=8.00s (8s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  INSERT IGNORE INTO 'subscriptions' ('user_id', 'feed_id') VALUES (N, N)

Count: 38  Time=7.92s (301s)  Lock=0.00s (0s)  Rows=1.0 (38), superfeeder[superfeeder]@[172.21.1.184]
  SELECT count(DISTINCT 'users'.id) AS count_users_id FROM 'users'  INNER JOIN 'subscriptions' ON 'users'.id = 'subscriptions'.user_id    WHERE (('subscriptions'.feed_id = N))

Count: 9  Time=7.67s (69s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  INSERT IGNORE INTO 'feeds' ('url') VALUES ('S')

Count: 244  Time=7.20s (1756s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = N, 'last_sup_update_id' = NULL, 'updated_at' = 'S', 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = N, 'active' = 'S', 'last_fetch' = 'S', 'created_at' = 'S', 'max_period' = 'S' WHERE ('id' = N)

Count: 336  Time=6.85s (2301s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = N, 'last_sup_update_id' = NULL, 'updated_at' = 'S', 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = N, 'active' = 'S', 'last_fetch' = 'S', 'created_at' = NULL, 'max_period' = 'S' WHERE ('id' = N)

Count: 16  Time=6.38s (102s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = N, 'last_sup_update_id' = NULL, 'updated_at' = NULL, 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = N, 'active' = 'S', 'last_fetch' = 'S', 'created_at' = NULL, 'max_period' = 'S' WHERE ('id' = N)

Count: 122  Time=5.91s (721s)  Lock=0.00s (0s)  Rows=1.0 (119), superfeeder[superfeeder]@[172.21.1.158]
  SELECT DISTINCT 'users'.* FROM 'users' INNER JOIN 'subscriptions' ON ('subscriptions'.'user_id' = 'users'.'id') WHERE ('subscriptions'.'feed_id' = N)

Count: 299  Time=5.78s (1727s)  Lock=0.00s (0s)  Rows=1.0 (299), superfeeder[superfeeder]@[172.21.1.158]
  SELECT * FROM 'feeds' WHERE ('id' = 'S')

Count: 21  Time=5.48s (115s)  Lock=0.00s (0s)  Rows=1.0 (21), superfeeder[superfeeder]@[172.21.1.158]
  SELECT * FROM 'subscriptions' WHERE (('user_id' = N) AND ('feed_id' = N)) LIMIT N

Count: 27  Time=5.37s (145s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = 'S', 'last_sup_update_id' = NULL, 'updated_at' = NULL, 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = 'S', 'active' = 'S', 'last_fetch' = 'S', 'created_at' = NULL, 'max_period' = 'S' WHERE ('id' = N)

Count: 9  Time=4.33s (39s)  Lock=0.00s (0s)  Rows=0.0 (0), superfeeder[superfeeder]@[172.21.1.158]
  UPDATE 'feeds' SET 'last_error_message' = 'S', 'period' = 'S', 'last_sup_update_id' = NULL, 'updated_at' = NULL, 'modified' = 'S', 'fetch_session_id' = 'S', 'streamed' = 'S', 'last_parse' = 'S', 'etag' = 'S', 'last_entry_time' = 'S', 'min_period' = 'S', 'url' = 'S', 'id' = 'S', 'feed_type' = NULL, 'sup_id' = NULL, 'sup_url_id' = NULL, 'next_fetch' = 'S', 'hashed_content' = 'S', 'last_maintenance_at' = 'S', 'last_ping' = NULL, 'last_http_code' = NULL, 'active' = 'S', 'last_fetch' = 'S', 'created_at' = NULL, 'max_period' = 'S' WHERE ('id' = N)

Count: 1  Time=4.00s (4s)  Lock=0.00s (0s)  Rows=1.0 (1), superfeeder[superfeeder]@[172.21.1.175]
  select id from users where login='S'

Count: 1  Time=3.00s (3s)  Lock=0.00s (0s)  Rows=22.0 (22), debian-sys-maint[debian-sys-maint]@localhost
  select concat("S",
  TABLE_SCHEMA, "S", TABLE_NAME, "S") 
  from information_schema.TABLES where ENGINE="S"

Count: 1056  Time=0.11s (111s)  Lock=0.00s (0s)  Rows=126.9 (133998), superfeeder[superfeeder]@[172.21.1.184]
  SELECT * FROM 'feeds' WHERE (last_maintenance_at < 'S')

Count: 1049  Time=0.00s (1s)  Lock=0.00s (0s)  Rows=3.1 (3303), superfeeder[superfeeder]@[172.21.1.184]
  SELECT * FROM 'users' WHERE (one_week_anniversary_sent = N AND activated_at < 'S')

Count: 21  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=0.0 (0), 0users@0hosts
  administrator command: Ping

Count: 1  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=0.0 (0), debian-sys-maint[debian-sys-maint]@localhost
  select count(*) into @discard from 'information_schema'.'COLUMNS'

Count: 8  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=30.0 (240), superfeeder[superfeeder]@[172.21.1.184]
  SELECT DISTINCT 'feeds'.* FROM 'feeds' INNER JOIN 'subscriptions' ON 'feeds'.id = 'subscriptions'.feed_id WHERE (('subscriptions'.user_id = N)) AND (('subscriptions'.user_id = N))  LIMIT N, N

Count: 31  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=1.0 (31), superfeeder[superfeeder]@2hosts
  SELECT count(*) AS count_all FROM 'feeds'

Count: 1  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=0.0 (0), debian-sys-maint[debian-sys-maint]@localhost
  select count(*) into @discard from 'information_schema'.'TRIGGERS'

Count: 1  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=0.0 (0), debian-sys-maint[debian-sys-maint]@localhost
  select count(*) into @discard from 'information_schema'.'VIEWS'

Count: 52  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=0.7 (34), superfeeder[superfeeder]@[172.21.1.184]
  SELECT * FROM 'users' WHERE ('users'.'remember_token' = 'S')  LIMIT N

Count: 120  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=1.0 (120), superfeeder[superfeeder]@2hosts
  SELECT * FROM 'feeds'  ORDER BY feeds.id DESC LIMIT N

Count: 19  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=15.7 (299), superfeeder[superfeeder]@2hosts
  SELECT count(*) AS count_all, last_http_code AS last_http_code FROM 'feeds'  GROUP BY last_http_code

Count: 1  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=0.0 (0), debian-sys-maint[debian-sys-maint]@localhost
  select count(*) into @discard from 'information_schema'.'ROUTINES'

Count: 1  Time=0.00s (0s)  Lock=0.00s (0s)  Rows=1.0 (1), debian-sys-maint[debian-sys-maint]@localhost
  SELECT count(*) FROM mysql.user WHERE user='S' and password='S'

Definição de tabela para feeds:

+---------------------+--------------+------+-----+---------------------+----------------+
| Field               | Type         | Null | Key | Default             | Extra          |
+---------------------+--------------+------+-----+---------------------+----------------+
| id                  | int(11)      | NO   | PRI | NULL                | auto_increment | 
| url                 | varchar(255) | YES  | UNI | NULL                |                | 
| last_parse          | datetime     | YES  |     | 2009-08-10 14:51:46 |                | 
| etag                | varchar(255) | YES  |     | etag                |                | 
| modified            | datetime     | YES  |     | 2009-08-10 14:51:46 |                | 
| active              | tinyint(1)   | YES  | MUL | 1                   |                | 
| last_fetch          | datetime     | YES  |     | 2009-08-10 14:51:46 |                | 
| next_fetch          | datetime     | YES  | MUL | 2009-08-10 14:51:46 |                | 
| fetch_session_id    | varchar(255) | YES  | MUL |                     |                | 
| period              | int(11)      | YES  |     | 240                 |                | 
| hashed_content      | varchar(255) | YES  |     |                     |                | 
| streamed            | tinyint(1)   | YES  |     | 0                   |                | 
| sup_id              | varchar(255) | YES  | MUL | NULL                |                | 
| last_sup_update_id  | varchar(255) | YES  |     | NULL                |                | 
| last_entry_time     | datetime     | YES  |     | 2009-08-10 14:51:46 |                | 
| last_ping           | datetime     | YES  |     | NULL                |                | 
| last_http_code      | int(11)      | YES  |     | NULL                |                | 
| last_error_message  | varchar(255) | YES  |     |                     |                | 
| sup_url_id          | int(11)      | YES  | MUL | NULL                |                | 
| created_at          | datetime     | YES  |     | NULL                |                | 
| updated_at          | datetime     | YES  |     | NULL                |                | 
| last_maintenance_at | datetime     | YES  |     | 2008-08-10 21:51:50 |                | 
| min_period          | int(11)      | YES  |     | 60                  |                | 
| max_period          | int(11)      | YES  |     | 900                 |                | 
+---------------------+--------------+------+-----+---------------------+----------------+

+-------+------------+--------------------------------------+--------------+------------------+-----------+-------------+----------+--------+------+------------+---------+
| Table | Non_unique | Key_name                             | Seq_in_index | Column_name      | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment |
+-------+------------+--------------------------------------+--------------+------------------+-----------+-------------+----------+--------+------+------------+---------+
| feeds |          0 | PRIMARY                              |            1 | id               | A         |         166 |     NULL | NULL   |      | BTREE      |         | 
| feeds |          0 | index_feeds_on_url                   |            1 | url              | A         |         166 |     NULL | NULL   | YES  | BTREE      |         | 
| feeds |          1 | index_feeds_on_next_fetch_and_active |            1 | next_fetch       | A         |           1 |     NULL | NULL   | YES  | BTREE      |         | 
| feeds |          1 | index_feeds_on_next_fetch_and_active |            2 | active           | A         |           1 |     NULL | NULL   | YES  | BTREE      |         | 
| feeds |          1 | index_feeds_on_sup_id                |            1 | sup_id           | A         |           1 |     NULL | NULL   | YES  | BTREE      |         | 
| feeds |          1 | index_feeds_on_sup_url_id            |            1 | sup_url_id       | A         |           1 |     NULL | NULL   | YES  | BTREE      |         | 
| feeds |          1 | index_feeds_on_fetch_session_id      |            1 | fetch_session_id | A         |           1 |     NULL | NULL   | YES  | BTREE      |         | 
+-------+------------+--------------------------------------+--------------+------------------+-----------+-------------+----------+--------+------+------------+---------+
    
por Julien Genestoux 12.08.2009 / 17:40

5 respostas

11

Você provavelmente não deve considerar MyISAM, INNODB irá trabalhar para você. O MyISAM é talvez mais rápido quando se trata de SELECT , mas (por exemplo) bloqueia sua tabela completa em atualizações.

Quanto a INNODB:

  • geralmente, considere sempre mais memória RAM antes de entrar em sharding (tamanho do DB = ~ RAM)
  • dê uma olhada nas seguintes variáveis:
    • innodb_buffer_pool_size (usamos cerca de 60-70% da nossa memória)
    • innodb_log_file_size
    • innodb_log_buffer_size
    • innodb_flush_log_at_trx_commit
    • innodb_thread_concurrency
    • innodb_flush_method=O_DIRECT
    • innodb_file_per_table
  • mude de innodb para xtradb (mesma API)
  • use as construções do percona (elas contêm patches de desempenho do Google, etc.)

Ótima leitura:

Em uma nota lateral:

  • uma fatia de 2 GB não é suficiente para executar esta
  • ainda mais achei o armazenamento em slicehost um pouco lento (io é um fator)
  • na nuvem, pode fazer sentido fragmentar mais cedo (causa do limite de RAM)
  • Eu executaria todas consultas por meio de EXPLAIN para garantir que o índice estivesse realmente sendo usado
por 12.08.2009 / 18:19
2

Eu achei que o MySQLTuner era muito eficaz no passado - ele pode fazer sugestões sensatas para alterações de configuração com base no uso do seu servidor. É baseado no script tuning-primer , que também vale a pena tentar.

    
por 12.08.2009 / 17:59
1

Seu aplicativo libera as conexões com o pool quando ele termina suas coisas?

    
por 13.08.2009 / 00:46
0

Se você puder substituir as cláusulas where por IDs específicos (supondo que não haja muitos), isso poderá acelerar essas atualizações.

Usar algo como pesquisa de esfinge, que você pode agrupar com facilidade para encontrar itens antecipadamente, ajudará. Eu ouvi que pode retornar pesquisas mais rápido do que o mysql sabe que tem índices.

link

    
por 12.08.2009 / 17:43
0

Verifique novamente as consultas que estão demorando muito tempo. As tabelas estão indexadas corretamente?

Você também pode executar o MySQL Tuner para ajustar suas configurações de mysql.

    
por 12.08.2009 / 18:00