1.配置环境：
2.问题描述： mysql可以正常启动，但超过一段时间（10到30分钟），从自己的停止; SSH命令行如下所示
# /usr/bin/mysqld_safe: line 183: 9161 Killed nohup /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock < /dev/null > /dev/null 2>&1
mysql停止然后直接启动是不够的，将报告如下：
# service mysqld restart
Stopping mysqld: [ OK ]
MySQL Daemon failed to start.
Starting mysqld: [FAILED]
但首先重启httpd，然后启动mysqld就能正常启动;
# service mysqld restart
Stopping mysqld: [ OK ]
MySQL Daemon failed to start.
Starting mysqld: [FAILED]
[root@localhost ~]# service httpd restart
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
[root@localhost ~]# service mysqld restart
Stopping mysqld: [ OK ]
Starting mysqld: [ OK ]
Mysqld.log：
2017-09-05 23:03:34 10926 [Note] InnoDB: Using atomics to ref count buffer pool pages
2017-09-05 23:03:34 10926 [Note] InnoDB: The InnoDB memory heap is disabled
2017-09-05 23:03:34 10926 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2017-09-05 23:03:34 10926 [Note] InnoDB: Memory barrier is not used
2017-09-05 23:03:34 10926 [Note] InnoDB: Compressed tables use zlib 1.2.3
2017-09-05 23:03:34 10926 [Note] InnoDB: Using Linux native AIO
2017-09-05 23:03:34 10926 [Note] InnoDB: Using CPU crc32 instructions
2017-09-05 23:03:34 10926 [Note] InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137363456 bytes) failed; errno 12
2017-09-05 23:03:34 10926 [ERROR] InnoDB: Cannot allocate memory for the buffer pool
2017-09-05 23:03:34 10926 [ERROR] Plugin 'InnoDB' init function returned error.
2017-09-05 23:03:34 10926 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
2017-09-05 23:03:34 10926 [ERROR] Unknown/unsupported storage engine: InnoDB
2017-09-05 23:03:34 10926 [ERROR] Aborting
2017-09-05 23:03:34 10926 [Note] Binlog end
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'partition'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'FEDERATED'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_DATAFILES'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_TABLESPACES'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN_COLS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_FIELDS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_COLUMNS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_INDEXES'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_TABLESTATS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_SYS_TABLES'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_FT_INDEX_TABLE'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_FT_INDEX_CACHE'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_FT_CONFIG'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_FT_BEING_DELETED'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_FT_DELETED'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_FT_DEFAULT_STOPWORD'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_METRICS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_BUFFER_POOL_STATS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE_LRU'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX_RESET'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_CMPMEM'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_CMP_RESET'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_CMP'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_LOCK_WAITS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_LOCKS'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'INNODB_TRX'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'ARCHIVE'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'BLACKHOLE'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'CSV'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'MEMORY'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'MRG_MYISAM'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'MyISAM'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'sha256_password'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'mysql_old_password'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'mysql_native_password'
2017-09-05 23:03:34 10926 [Note] Shutting down plugin 'binlog'
2017-09-05 23:03:34 10926 [Note] /usr/sbin/mysqld: Shutdown complete
2017-09-05 23:11:21 11670 [Note] InnoDB: Using atomics to ref count buffer pool pages
2017-09-05 23:11:21 11670 [Note] InnoDB: The InnoDB memory heap is disabled
2017-09-05 23:11:21 11670 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2017-09-05 23:11:21 11670 [Note] InnoDB: Memory barrier is not used
2017-09-05 23:11:21 11670 [Note] InnoDB: Compressed tables use zlib 1.2.3
2017-09-05 23:11:21 11670 [Note] InnoDB: Using Linux native AIO
2017-09-05 23:11:21 11670 [Note] InnoDB: Using CPU crc32 instructions
2017-09-05 23:11:21 11670 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2017-09-05 23:11:21 11670 [Note] InnoDB: Completed initialization of buffer pool
2017-09-05 23:11:21 11670 [Note] InnoDB: Highest supported file format is Barracuda.
2017-09-05 23:11:21 11670 [Note] InnoDB: The log sequence numbers 0 and 0 in ibdata files do not match the log sequence number 1600617 in the ib_logfiles!
2017-09-05 23:11:21 11670 [Note] InnoDB: Database was not shutdown normally!
2017-09-05 23:11:21 11670 [Note] InnoDB: Starting crash recovery.
2017-09-05 23:11:21 11670 [Note] InnoDB: Reading tablespace information from the .ibd files...
2017-09-05 23:11:21 11670 [Note] InnoDB: Restoring possible half-written data pages
2017-09-05 23:11:21 11670 [Note] InnoDB: from the doublewrite buffer...
2017-09-05 23:11:21 11670 [Note] InnoDB: 128 rollback segment(s) are active.
2017-09-05 23:11:21 11670 [Note] InnoDB: Waiting for purge to start
2017-09-05 23:11:21 11670 [Note] InnoDB: 5.6.37 started; log sequence number 1600617
2017-09-05 23:11:21 11670 [Note] Server hostname (bind-address): '*'; port: 3306
2017-09-05 23:11:21 11670 [Note] IPv6 is available.
2017-09-05 23:11:21 11670 [Note] - '::' resolves to '::';
2017-09-05 23:11:21 11670 [Note] Server socket created on IP: '::'.
2017-09-05 23:11:21 11670 [Note] Event Scheduler: Loaded 0 events
2017-09-05 23:11:21 11670 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.6.37' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL)
3.尝试过其他方法： 卸载并重新安装mysqld，问题仍然存在;