Ubuntu mysql停止工作

我在ubuntu 14服务器上安装了vps。我安装了灯组。一切正常，但mysql服务器经常停止，我必须手动重新启动它。这是我的my.cnf mysql配置文件

# 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 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
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address        = 127.0.0.1
#
# * 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        = 100
#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.
# 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
#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/

下面是我的mysqltuner输出

-------- General Statistics ------------------------------------------------
[--] Skipped version check for MySQLTuner script
[OK] Currently running supported MySQL version 5.5.49-0ubuntu0.14.04.1
[OK] Operating on 64-bit architecture

-------- Storage Engine Statistics -------------------------------------------
[--] Status: +Archive -BDB -Federated +InnoDB -ISAM -NDBCluster 
[--] Data in MyISAM tables: 38K (Tables: 34)
[--] Data in PERFORMANCE_SCHEMA tables: 0B (Tables: 17)
[--] Data in InnoDB tables: 11M (Tables: 101)
[!!] Total fragmented tables: 101

-------- Security Recommendations  -------------------------------------------
[OK] All database users have passwords assigned

-------- Performance Metrics -------------------------------------------------
[--] Up for: 1h 13m 27s (2K q [0.464 qps], 130 conn, TX: 5M, RX: 332K)
[--] Reads / Writes: 81% / 19%
[--] Total buffers: 192.0M global + 2.7M per thread (151 max threads)
[!!] Maximum possible memory usage: 597.8M (121% of installed RAM)
[OK] Slow queries: 0% (0/2K)
[OK] Highest usage of available connections: 7% (12/151)
[OK] Key buffer size / total MyISAM indexes: 16.0M/196.0K
[OK] Query cache efficiency: 33.9% (493 cached / 1K selects)
[OK] Query cache prunes per day: 0
[OK] Sorts requiring temporary tables: 0% (0 temp sorts / 77 sorts)
[!!] Temporary tables created on disk: 33% (166 on disk / 498 total)
[OK] Thread cache hit rate: 90% (12 created / 130 connections)
[OK] Table cache hit rate: 94% (178 open / 189 opened)
[OK] Open file limit used: 11% (116/1K)
[OK] Table locks acquired immediately: 100% (1K immediate / 1K locks)
[OK] InnoDB data size / buffer pool: 11.9M/128.0M

-------- Recommendations -----------------------------------------------------
    General recommendations:
    Run OPTIMIZE TABLE to defragment tables for better performance
    MySQL started within last 24 hours - recommendations may be inaccurate
    Reduce your overall MySQL memory footprint for system stability
    Enable the slow query log to troubleshoot bad queries
    When making adjustments, make tmp_table_size/max_heap_table_size equal
    Reduce your SELECT DISTINCT queries without LIMIT clauses
Variables to adjust:
  *** MySQL's maximum memory usage is dangerously high ***
  *** Add RAM before increasing MySQL buffer variables ***
    tmp_table_size (> 16M)
    max_heap_table_size (> 16M)

这是我的记忆

Every 5.0s: free -m                                                         Sun Jul  3 03:12:12 2016

         total       used       free     shared    buffers     cached

成员：490 476 13 64 10 183 -/+缓冲区/高速缓存：281208 掉期：0

---

这里可能有什么问题。my.cnf上是否存在一些错误配置，或者其他什么正在扼杀mysql。请帮我找到问题。

可能是mysql内存不足。当系统缺少交换时会发生这种情况（即当内存耗尽时，程序无法从主内存传输到“交换”文件以防止系统内存故障）

掉期说明来自：

Linux将其物理RAM（随机访问内存）划分为多个磁盘 内存称为页。交换是将一页内存 复制到硬盘上的预配置空间，称为交换 空间，以释放该页内存。组合尺寸的 物理内存和交换空间是虚拟内存的数量 可用

您可以调整“innodb\u buffer\u pool\u size”以减少索引和缓存内存中的内存占用

理想情况下，可以将缓冲池的大小设置为最大值 实用，为服务器上的其他进程保留足够的内存 在没有过多分页的情况下运行。缓冲池越大，容量越大 InnoDB就像内存中的数据库，从磁盘读取数据一次 然后在后续读取期间访问内存中的数据。 使用innodb_Buffer_pool_大小配置缓冲池大小 配置选项

根据：

解决方案：

将此添加到[mysqld]下：

innodb\u buffer\u pool\u size=64M

然后制作一个交换文件：

dd if=/dev/zero of=/swapfile bs=100M计数=40

mkswap/swapfile

swapon/swapfile

并将其添加到

/etc/fstab

：

---

/swapfile none swap sw 0 0

您可以发布

tail/var/log/mysql/error.log的输出吗？error.log文件中没有任何内容。它是空的。我应该在my.cnf innodb_buffer_pool_size=64M上添加这一行吗？你能解释一下交换文件吗。这能做什么？它将帮助其他有类似问题的用户。感谢您将其添加到
my.cnf
文件中。当然，我会在文章中添加额外的解释。希望它能解决你的问题。