Mariadb server shuts down itself after some days running on centos 7.

Mariadb : 5.5.44
centos 7
RAM 2 GB (which i see only 50% usage)

following is I see at the last 100 lines of the log.

Complete dump of log here. (http://www.merochord.info/mariadb.log)

160312 20:12:30 mysqldsafe Number of processes running now: 0
160312 20:12:30 mysqldsafe mysqld restarted
160312 20:12:31 [Note] /usr/libexec/mysqld (mysqld 5.5.44-MariaDB-log) starting as process 17041 ...
160312 20:12:31 InnoDB: The InnoDB memory heap is disabled
160312 20:12:31 InnoDB: Mutexes and rw_locks use GCC atomic builtins
160312 20:12:31 InnoDB: Compressed tables use zlib 1.2.7
160312 20:12:31 InnoDB: Using Linux native AIO
160312 20:12:31 InnoDB: Initializing buffer pool, size = 128.0M
InnoDB: mmap(137756672 bytes) failed; errno 12
160312 20:12:31 InnoDB: Completed initialization of buffer pool
160312 20:12:31 InnoDB: Fatal error: cannot allocate memory for the buffer pool
160312 20:12:31 [ERROR] Plugin 'InnoDB' init function returned error.
160312 20:12:31 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
160312 20:12:31 [ERROR] mysqld: Out of memory (Needed 128917504 bytes)
160312 20:12:31 [ERROR] mysqld: Out of memory (Needed 96681984 bytes)
160312 20:12:31 [ERROR] mysqld: Out of memory (Needed 72499200 bytes)
160312 20:12:31 [Note] Plugin 'FEEDBACK' is disabled.
160312 20:12:31 [ERROR] Unknown/unsupported storage engine: InnoDB
160312 20:12:31 [ERROR] Aborting

160312 20:12:31 [Note] /usr/libexec/mysqld: Shutdown complete

160312 20:12:31 mysqldsafe mysqld from pid file /var/run/mariadb/mariadb.pid ended
160313 08:39:00 mysqldsafe Starting mysqld daemon with databases from /var/lib/mysql
160313 8:39:01 [Note] /usr/libexec/mysqld (mysqld 5.5.44-MariaDB-log) starting as process 21981 ...
160313 8:39:01 InnoDB: The InnoDB memory heap is disabled
160313 8:39:01 InnoDB: Mutexes and rwlocks use GCC atomic builtins
160313 8:39:01 InnoDB: Compressed tables use zlib 1.2.7
160313 8:39:01 InnoDB: Using Linux native AIO
160313 8:39:01 InnoDB: Initializing buffer pool, size = 128.0M
160313 8:39:01 InnoDB: Completed initialization of buffer pool
160313 8:39:01 InnoDB: highest supported file format is Barracuda.
InnoDB: The log sequence number in ibdata files does not match
InnoDB: the log sequence number in the iblogfiles!
160313 8:39:01 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
InnoDB: Last MySQL binlog file position 0 9491224, file name /var/lib/mysql/mysql-bin.000064
160313 8:39:04 InnoDB: Waiting for the background threads to start
160313 8:39:05 Percona XtraDB (http://www.percona.com) 5.5.43-MariaDB-37.2 started; log sequence number 6810097075
160313 8:39:05 [Note] Plugin 'FEEDBACK' is disabled.
160313 8:39:05 [Note] Recovering after a crash using /var/lib/mysql/mysql-bin
160313 8:39:05 [Note] Starting crash recovery...
160313 8:39:05 [Note] Crash recovery finished.
160313 8:39:05 [Note] Server socket created on IP: '0.0.0.0'.
160313 8:39:05 [Note] Event Scheduler: Loaded 0 events
160313 8:39:05 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.5.44-MariaDB-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 MariaDB Server
160313 8:39:06 [ERROR] mysqld: Table './sajhamanch@002eorg/news' is marked as crashed and should be repaired
160313 8:39:06 [Warning] Checking table: './sajhamanch@002eorg/news'
160313 9:34:42 [Note] /usr/libexec/mysqld: Normal shutdown

160313 9:34:42 [Note] Event Scheduler: Purging the queue. 0 events
160313 9:34:42 InnoDB: Starting shutdown...
160313 9:34:43 InnoDB: Shutdown completed; log sequence number 6810100584
160313 9:34:43 [Note] /usr/libexec/mysqld: Shutdown complete

160313 09:34:43 mysqldsafe mysqld from pid file /var/run/mariadb/mariadb.pid ended
160313 09:34:43 mysqldsafe Starting mysqld daemon with databases from /var/lib/mysql
160313 9:34:44 [Note] /usr/libexec/mysqld (mysqld 5.5.44-MariaDB-log) starting as process 24842 ...
160313 9:34:44 InnoDB: The InnoDB memory heap is disabled
160313 9:34:44 InnoDB: Mutexes and rw_locks use GCC atomic builtins
160313 9:34:44 InnoDB: Compressed tables use zlib 1.2.7
160313 9:34:44 InnoDB: Using Linux native AIO
160313 9:34:44 InnoDB: Initializing buffer pool, size = 128.0M
160313 9:34:44 InnoDB: Completed initialization of buffer pool
160313 9:34:44 InnoDB: highest supported file format is Barracuda.
160313 9:34:44 InnoDB: Waiting for the background threads to start
160313 9:34:45 Percona XtraDB (http://www.percona.com) 5.5.43-MariaDB-37.2 started; log sequence number 6810100584
160313 9:34:45 [Note] Plugin 'FEEDBACK' is disabled.
160313 9:34:45 [Note] Server socket created on IP: '0.0.0.0'.
160313 9:34:45 [Note] Event Scheduler: Loaded 0 events
160313 9:34:45 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.5.44-MariaDB-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 MariaDB Server