博客几天不动，今天打开访问不了了，出现数据库没连接的错误。

       登陆后台，想登陆mysql，出现：Can't connect to local MySQL server through socket '/tmp/mysql.sock'。

       重启，关闭失败，打开成功，说明mysql不知什么自己关闭了。

重启mysql.png

        再查看日志，发现前天下午就挂了 


160801 16:48:33 mysqld_safe Number of processes running now: 0
160801 16:48:33 mysqld_safe mysqld restarted
2016-08-01 16:48:33 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2016-08-01 16:48:34 26972 [Note] Plugin 'FEDERATED' is disabled.
2016-08-01 16:48:34 26972 [Note] InnoDB: Using atomics to ref count buffer pool pages
2016-08-01 16:48:34 26972 [Note] InnoDB: The InnoDB memory heap is disabled
2016-08-01 16:48:34 26972 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2016-08-01 16:48:34 26972 [Note] InnoDB: Memory barrier is not used
2016-08-01 16:48:34 26972 [Note] InnoDB: Compressed tables use zlib 1.2.3
2016-08-01 16:48:34 26972 [Note] InnoDB: Using Linux native AIO
2016-08-01 16:48:34 26972 [Note] InnoDB: Using CPU crc32 instructions
2016-08-01 16:48:34 26972 [Note] InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137363456 bytes) failed; errno 12
2016-08-01 16:48:34 26972 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2016-08-01 16:48:34 26972 [ERROR] Plugin 'InnoDB' init function returned error.
2016-08-01 16:48:34 26972 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2016-08-01 16:48:34 26972 [ERROR] Unknown/unsupported storage engine: InnoDB
2016-08-01 16:48:34 26972 [ERROR] Aborting

2016-08-01 16:48:34 26972 [Note] Binlog end
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'partition'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'BLACKHOLE'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_DATAFILES'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_TABLESPACES'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN_COLS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_FIELDS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_COLUMNS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_INDEXES'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_TABLESTATS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_SYS_TABLES'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_FT_INDEX_TABLE'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_FT_INDEX_CACHE'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_FT_CONFIG'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_FT_BEING_DELETED'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_FT_DELETED'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_FT_DEFAULT_STOPWORD'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_METRICS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_BUFFER_POOL_STATS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE_LRU'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX_RESET'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_CMPMEM'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_CMP_RESET'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_CMP'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_LOCK_WAITS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_LOCKS'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'INNODB_TRX'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'ARCHIVE'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'MyISAM'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'CSV'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'MRG_MYISAM'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'MEMORY'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'sha256_password'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'mysql_old_password'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'mysql_native_password'
2016-08-01 16:48:34 26972 [Note] Shutting down plugin 'binlog'
2016-08-01 16:48:34 26972 [Note] /*/*/*/*/mysqld: Shutdown complete

160801 16:48:34 mysqld_safe mysqld from pid file /*/*/mysql/data/iZ28sj5gtwxZ.pid ended

        查看磁盘，空间是足的，还有30G剩余空间。

        什么原因呢？