我在 Cloud Azure 中开始了一个项目。我的机器是 3.5GB RAM，30Gb 大小。4G os Swap 以防万一。我们运行的应用程序使用 mysqlnd 服务器 5.6.28 和 Apache/2.4.7 (Ubuntu) (preFork)。
我的数据库大小约为 1GB。
问题： 昨天我试图使用 phpmyadmin 将整个数据库复制到另一个名称，并且所有服务器开始减速（mysql）使用大约 100％的 CPU 并使我的 beta 用户对 mysql 的请求开始像地狱一样滞后，我有重新启动mysql服务器。
我不明白出了什么问题。我尝试使用 percona 向导优化 my.cnf 文件。
我在那台机器上只有大约 3 个 beta 用户，每秒的请求数约为 15，正如我的 apache 服务器状态所说。分配给 db 大小为 2GB 的 3.5GB 不能完成这个复制数据库任务！？一个简单的命令...
Parent Server Config. Generation: 5
Parent Server MPM Generation: 4
Server uptime: 12 days 19 hours 47 minutes 6 seconds
Server load: 0.25 0.26 0.27
Total accesses: 598877 - Total Traffic: 2.2 GB
CPU Usage: u697.64 s206.04 cu0 cs0 - .0816% CPU load
.54 requests/sec - 2180 B/second - 4033 B/request
10 requests currently being processed, 39 idle workers
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这是我的.cnf：
# The MySQL database server configuration file.
[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
#
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-messages-dir = /usr/share/mysql
skip-external-locking
skip-name-resolve
#skip-locking
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#disabled to allow remote access
#bind-address = 127.0.0.1
bind-address = 10.0.0.4
#
# * Fine Tuning
#
key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 256K
thread_cache_size = 32
#thread_cache_size=0
host_cache_size=0
# This replaces the startup script and checks MyISAM tables if needed
# the first time they are touched
myisam-recover = BACKUP
max_connections = 800
#table_cache = 64
thread_concurrency = 100
join_buffer_size=128
#
# * Query Cache Configuration
#
query_cache_limit = 128M
#query_cache_size = 64M
#query_cache_size = 128M
#
# * 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 log - should be very few entries.
log_error = /var/log/mysql/error.log
# Here you can see queries with especially long duration
#log_slow_queries = /var/log/mysql/mysql-slow.log
slow-query-log=1
long_query_time = 10
#log-queries-not-using-indexes
#server-id = 1
#log_bin = /var/log/mysql/mysql-bin.log
expire_logs_days = 7
max_binlog_size = 60M
#binlog_do_db = include_database_name
#binlog_ignore_db = include_database_name
#
# * InnoDB
#
innodb_buffer_pool_size=2G
#innodb_log_file_size = 2G
#innodb_buffer_pool_instances=1
# 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/
在那个 conf.d 文件夹上我也有这个（percona 向导）：
#
# The MySQL 5.6 database server configuration file.
#
# This custom MySQL 5.6 specific configuration file
# adds on top of the existing default my.cnf file at
# - /etc/mysql/my.cnf.
#
# Please add any extra MySQL 5.6 options in this file
# for sake of clarity.
#
# You may uncomment any existing option to enable it
#
# sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
# Generated by Percona Configuration Wizard (http://tools.percona.com/) version REL5-20120208
[mysql]
# CLIENT #
#port = 3306
#socket = /var/lib/mysql/mysql.sock
[mysqld]
# GENERAL #
user = mysql
default-storage-engine = InnoDB
#socket = /var/lib/mysql/mysql.sock
#pid-file = /var/lib/mysql/mysql.pid
# MyISAM #
key-buffer-size = 32M
myisam-recover = FORCE,BACKUP
# SAFETY #
max-allowed-packet = 16M
max-connect-errors = 1000000
sql-mode = STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_AUTO_VALUE_ON_ZERO,NO_ENGINE_SUBSTITUTION,NO_ZERO_DATE,NO_ZERO_IN_DATE,ONLY_FULL_GROUP_BY
innodb = FORCE
innodb-strict-mode = 1
# DATA STORAGE #
datadir = /var/lib/mysql/
# BINARY LOGGING #
log-bin = /var/lib/mysql/mysql-bin
expire-logs-days = 14
sync-binlog = 1
# CACHES AND LIMITS #
tmp-table-size = 32M
max-heap-table-size = 32M
query-cache-type = 0
query-cache-size = 0
max-connections = 500
thread-cache-size = 50
open-files-limit = 65535
table-definition-cache = 4096
table-open-cache = 4096
# INNODB #
innodb-flush-method = O_DIRECT
innodb-log-files-in-group = 2
innodb-log-file-size = 128M
innodb-flush-log-at-trx-commit = 1
innodb-file-per-table = 1
innodb-buffer-pool-size = 2G
# LOGGING #
log-error = /var/lib/mysql/mysql-error.log
log-queries-not-using-indexes = 1
slow-query-log = 1
slow-query-log-file = /var/lib/mysql/mysql-slow.log
这是“cron”备份的错误日志，它也创建了这种东西。
2016-04-25 06:42:13 32387 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead.
2016-04-25 06:42:13 32387 [Note] Plugin 'FEDERATED' is disabled.
2016-04-25 06:42:13 32387 [ERROR] Function 'innodb' already exists
2016-04-25 06:42:13 32387 [Warning] Couldn't load plugin named 'innodb' with soname 'ha_innodb.so'.
2016-04-25 06:42:13 32387 [ERROR] Function 'federated' already exists
2016-04-25 06:42:13 32387 [Warning] Couldn't load plugin named 'federated' with soname 'ha_federated.so'.
2016-04-25 06:42:13 32387 [ERROR] Function 'blackhole' already exists
2016-04-25 06:42:13 32387 [Warning] Couldn't load plugin named 'blackhole' with soname 'ha_blackhole.so'.
2016-04-25 06:42:13 32387 [ERROR] Function 'archive' already exists
2016-04-25 06:42:13 32387 [Warning] Couldn't load plugin named 'archive' with soname 'ha_archive.so'.
2016-04-25 06:42:13 32387 [Note] InnoDB: Using atomics to ref count buffer pool pages
2016-04-25 06:42:13 32387 [Note] InnoDB: The InnoDB memory heap is disabled
2016-04-25 06:42:13 32387 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-04-25 06:42:13 32387 [Note] InnoDB: Memory barrier is not used
2016-04-25 06:42:13 32387 [Note] InnoDB: Compressed tables use zlib 1.2.8
2016-04-25 06:42:13 32387 [Note] InnoDB: Using Linux native AIO
2016-04-25 06:42:13 32387 [Note] InnoDB: Not using CPU crc32 instructions
2016-04-25 06:42:13 32387 [Note] InnoDB: Initializing buffer pool, size = 2.0G
2016-04-25 06:42:13 32387 [Note] InnoDB: Completed initialization of buffer pool
2016-04-25 06:42:14 32387 [Note] InnoDB: Highest supported file format is Barracuda.
2016-04-25 06:42:14 32387 [Note] InnoDB: Log scan progressed past the checkpoint lsn 2666162556
2016-04-25 06:42:14 32387 [Note] InnoDB: Database was not shutdown normally!
2016-04-25 06:42:14 32387 [Note] InnoDB: Starting crash recovery.
2016-04-25 06:42:14 32387 [Note] InnoDB: Reading tablespace information from the .ibd files...
2016-04-25 06:42:22 32387 [Note] InnoDB: Restoring possible half-written data pages
2016-04-25 06:42:22 32387 [Note] InnoDB: from the doublewrite buffer...
InnoDB: Doing recovery: scanned up to log sequence number 2666163324
2016-04-25 19:01:42 35591 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead.
2016-04-25 19:01:42 35591 [Note] Plugin 'FEDERATED' is disabled.
2016-04-25 19:01:42 35591 [ERROR] Function 'innodb' already exists
2016-04-25 19:01:42 35591 [Warning] Couldn't load plugin named 'innodb' with soname 'ha_innodb.so'.
2016-04-25 19:01:42 35591 [ERROR] Function 'federated' already exists
2016-04-25 19:01:42 35591 [Warning] Couldn't load plugin named 'federated' with soname 'ha_federated.so'.
2016-04-25 19:01:42 35591 [ERROR] Function 'blackhole' already exists
2016-04-25 19:01:42 35591 [Warning] Couldn't load plugin named 'blackhole' with soname 'ha_blackhole.so'.
2016-04-25 19:01:42 35591 [ERROR] Function 'archive' already exists
2016-04-25 19:01:42 35591 [Warning] Couldn't load plugin named 'archive' with soname 'ha_archive.so'.
2016-04-25 19:01:42 35591 [Note] InnoDB: Using atomics to ref count buffer pool pages
2016-04-25 19:01:42 35591 [Note] InnoDB: The InnoDB memory heap is disabled
2016-04-25 19:01:42 35591 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-04-25 19:01:42 35591 [Note] InnoDB: Memory barrier is not used
2016-04-25 19:01:42 35591 [Note] InnoDB: Compressed tables use zlib 1.2.8
2016-04-25 19:01:42 35591 [Note] InnoDB: Using Linux native AIO
2016-04-25 19:01:42 35591 [Note] InnoDB: Not using CPU crc32 instructions
2016-04-25 19:01:42 35591 [Note] InnoDB: Initializing buffer pool, size = 2.0G
2016-04-25 19:01:42 35591 [Note] InnoDB: Completed initialization of buffer pool
2016-04-25 19:01:42 35591 [Note] InnoDB: Highest supported file format is Barracuda.
2016-04-25 19:01:42 35591 [Note] InnoDB: Log scan progressed past the checkpoint lsn 2666162556
2016-04-25 19:01:42 35591 [Note] InnoDB: Database was not shutdown normally!
2016-04-25 19:01:42 35591 [Note] InnoDB: Starting crash recovery.
2016-04-25 19:01:42 35591 [Note] InnoDB: Reading tablespace information from the .ibd files...
2016-04-25 19:01:42 35591 [Note] InnoDB: Restoring possible half-written data pages
2016-04-25 19:01:42 35591 [Note] InnoDB: from the doublewrite buffer...
InnoDB: Doing recovery: scanned up to log sequence number 2666163324
2016-04-25 19:01:42 35591 [Note] InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percent: 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed
2016-04-25 19:01:43 35591 [Note] InnoDB: 128 rollback segment(s) are active.
2016-04-25 19:01:43 35591 [Note] InnoDB: Waiting for purge to start
2016-04-25 19:01:43 35591 [Note] InnoDB: 5.6.28 started; log sequence number 2666163324
2016-04-25 19:01:43 35591 [Note] Server hostname (bind-address): '10.0.0.4'; port: 3306
2016-04-25 19:01:43 35591 [Note] - '10.0.0.4' resolves to '10.0.0.4';
2016-04-25 19:01:43 35591 [Note] Server socket created on IP: '10.0.0.4'.
2016-04-25 19:01:43 35591 [Warning] 'user' entry 'triconsulte@triconsulte' ignored in --skip-name-resolve mode.
2016-04-25 19:01:43 35591 [Warning] 'proxies_priv' entry '@ root@beautivmazure' ignored in --skip-name-resolve mode.
2016-04-25 19:01:43 35591 [Note] Event Scheduler: Loaded 0 events
2016-04-25 19:01:43 35591 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.6.28-0ubuntu0.14.04.1' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu)
2016-04-25 19:01:44 35591 [ERROR] /usr/sbin/mysqld: Table './beautipt_clean/bea_agenda' is marked as crashed and should be repaired
2016-04-25 19:01:44 35591 [Warning] Checking table: './beautipt_clean/bea_agenda'
2016-04-25 19:01:45 35591 [ERROR] /usr/sbin/mysqld: Table './beautipt_clean/cms_adminlog' is marked as crashed and should be repaired
2016-04-25 19:01:45 35591 [Warning] Checking table: './beautipt_clean/cms_adminlog'
2016-04-25 19:01:45 35591 [ERROR] /usr/sbin/mysqld: Table './beautipt_clean/cms_email_logs' is marked as crashed and should be repaired
2016-04-25 19:01:45 35591 [Warning] Checking table: './beautipt_clean/cms_email_logs'
2016-04-25 19:01:46 35591 [ERROR] /usr/sbin/mysqld: Table './beautipt_clean/cms_siteprefs' is marked as crashed and should be repaired
2016-04-25 19:01:46 35591 [Warning] Checking table: './beautipt_clean/cms_siteprefs'
2016-04-25 19:01:46 35591 [ERROR] /usr/sbin/mysqld: Table './beautipt_clean/ger_apilog' is marked as crashed and should be repaired
2016-04-25 19:01:46 35591 [Warning] Checking table: './beautipt_clean/ger_apilog'