wordpress websites msql errors.

Hi, i have 23 wordpress websites on my droplet (2 GB Memory / 40 GB Disk / NYC3). i take database errors, frequently. And i change my /etc/mysql/my.cnf :

skip-name-resolve max_connections = 500 # cok yogun sitelerde bu deger arttirilabilir thread_cache_size = 128 key_buffer = 128M
query_cache_type = 1 query_cache_size = 32M query_cache_limit = 4M table_cache = 2000 # cok fazla tablolu veritabanlarinda bu deger arttirilabilir low_priority_updates = 1

innodb_buffer_pool_size=256M innodb_additional_mem_pool_size=64M innodb_thread_concurrency=8 innodb_flush_method=O_DIRECT

my error logs: 160330 4:55:36 [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. 160330 4:55:36 [Note] Plugin ‘FEDERATED’ is disabled. 160330 4:55:36 InnoDB: The InnoDB memory heap is disabled 160330 4:55:36 InnoDB: Mutexes and rw_locks use GCC atomic builtins 160330 4:55:36 InnoDB: Compressed tables use zlib 1.2.8 160330 4:55:36 InnoDB: Using Linux native AIO 160330 4:55:36 InnoDB: Initializing buffer pool, size = 64.0M 160330 4:55:36 InnoDB: Completed initialization of buffer pool 160330 4:55:36 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 ib_logfiles! 160330 4:55:37 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… 160330 4:55:37 InnoDB: Waiting for the background threads to start 160330 4:55:38 InnoDB: 5.5.43 started; log sequence number 2320511750 160330 4:55:38 [Note] Server hostname (bind-address): ‘127.0.0.1’; port: 3306 160330 4:55:38 [Note] - ‘127.0.0.1’ resolves to ‘127.0.0.1’; 160330 4:55:38 [Note] Server socket created on IP: ‘127.0.0.1’. 160330 4:55:38 [Warning] ‘user’ entry ‘root@phpmyadmin-build’ ignored in --skip-name-resolve mode. 160330 4:55:38 [Warning] ‘proxies_priv’ entry ‘@ root@phpmyadmin-build’ ignored in --skip-name-resolve mode. 160330 4:55:38 [Note] Event Scheduler: Loaded 0 events 160330 4:55:38 [Note] /usr/sbin/mysqld: ready for connections. Version: ‘5.5.43-0ubuntu0.14.04.1’ socket: ‘/var/run/mysqld/mysqld.sock’ port: 3306 (Ubuntu) 160330 4:55:41 [ERROR] /usr/sbin/mysqld: Table ‘./lisztmuzik/wp_options’ is marked as crashed and should be repaired 160330 4:55:42 [Warning] Checking table: ‘./lisztmuzik/wp_options’ 160330 4:56:21 [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. 160330 4:56:21 [Note] Plugin ‘FEDERATED’ is disabled. 160330 4:56:21 InnoDB: The InnoDB memory heap is disabled 160330 4:56:21 InnoDB: Mutexes and rw_locks use GCC atomic builtins 160330 4:56:21 InnoDB: Compressed tables use zlib 1.2.8 160330 4:56:21 InnoDB: Using Linux native AIO 160330 4:56:21 InnoDB: Initializing buffer pool, size = 64.0M InnoDB: mmap(68681728 bytes) failed; errno 12 160330 4:56:21 InnoDB: Completed initialization of buffer pool 160330 4:56:21 InnoDB: Fatal error: cannot allocate memory for the buffer pool 160330 4:56:21 [ERROR] Plugin ‘InnoDB’ init function returned error. 160330 4:56:21 [ERROR] Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed. 160330 4:56:21 [ERROR] Unknown/unsupported storage engine: InnoDB 160330 4:56:21 [ERROR] Aborting

160330 4:56:21 [Note] /usr/sbin/mysqld: Shutdown complete

160330 4:56:22 [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. 160330 4:56:22 [Note] Plugin ‘FEDERATED’ is disabled. 160330 4:56:22 InnoDB: The InnoDB memory heap is disabled 160330 4:56:22 InnoDB: Mutexes and rw_locks use GCC atomic builtins 160330 4:56:22 InnoDB: Compressed tables use zlib 1.2.8 160330 4:56:22 InnoDB: Using Linux native AIO 160330 4:56:22 InnoDB: Initializing buffer pool, size = 64.0M InnoDB: mmap(68681728 bytes) failed; errno 12 160330 4:56:22 InnoDB: Completed initialization of buffer pool 160330 4:56:22 InnoDB: Fatal error: cannot allocate memory for the buffer pool 160330 4:56:22 [ERROR] Plugin ‘InnoDB’ init function returned error. 160330 4:56:22 [ERROR] Plugin ‘InnoDB’ registration as a STORAGE ENGINE failed. 160330 4:56:22 [ERROR] Unknown/unsupported storage engine: InnoDB 160330 4:56:22 [ERROR] Aborting

160330 4:56:22 [Note] /usr/sbin/mysqld: Shutdown complete

160330 5:07:11 [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. 160330 5:07:11 [Note] Plugin ‘FEDERATED’ is disabled. 160330 5:07:11 InnoDB: The InnoDB memory heap is disabled 160330 5:07:11 InnoDB: Mutexes and rw_locks use GCC atomic builtins 160330 5:07:11 InnoDB: Compressed tables use zlib 1.2.8 160330 5:07:11 InnoDB: Using Linux native AIO 160330 5:07:11 InnoDB: Initializing buffer pool, size = 64.0M 160330 5:07:11 InnoDB: Completed initialization of buffer pool 160330 5:07:11 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 ib_logfiles! 160330 5:07:11 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… 160330 5:07:11 InnoDB: Waiting for the background threads to start 160330 5:07:12 InnoDB: 5.5.43 started; log sequence number 2320513613 160330 5:07:12 [Note] Server hostname (bind-address): ‘127.0.0.1’; port: 3306 160330 5:07:12 [Note] - ‘127.0.0.1’ resolves to ‘127.0.0.1’; 160330 5:07:12 [Note] Server socket created on IP: ‘127.0.0.1’. 160330 5:07:12 [Warning] ‘user’ entry ‘root@phpmyadmin-build’ ignored in --skip-name-resolve mode. 160330 5:07:12 [Warning] ‘proxies_priv’ entry ‘@ root@phpmyadmin-build’ ignored in --skip-name-resolve mode. 160330 5:07:12 [Note] Event Scheduler: Loaded 0 events 160330 5:07:12 [Note] /usr/sbin/mysqld: ready for connections. Version: ‘5.5.43-0ubuntu0.14.04.1’ socket: ‘/var/run/mysqld/mysqld.sock’ port: 3306 (Ubuntu) 160330 5:07:14 [ERROR] /usr/sbin/mysqld: Table ‘./xdnyalsp_taylanc/wp_options’ is marked as crashed and should be repaired 160330 5:07:14 [Warning] Checking table: ‘./xdnyalsp_taylanc/wp_options’