Why can't I start mysql service on ec2 linux instance

Question

I get this error when starting mysql via ssh on my ec2 ami linux instance:

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/libysql/mysql.sock' (2)

Before running "mysql" command i tried to start mysql service:

sudo service mysqld start

but fails.

I checked for mysql.sock in the specified directory but it was missing. What is going on?

EDIT Also i changed permissions to these directories:

/var/lib/mysql/ => 755
all sub-directories in /var/lib/mysql => 700
all files in /var/lib/mysql => 660

EDIT I just uninstalled and re-installed mysql on my redhat ami ec2 instance. And I still can't start mysql service.

EDIT

Here is my mysql log:

    170506 04:31:30 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
    2017-05-06 04:31:30 6516 [Note] Plugin 'FEDERATED' is disabled.
    ^G/usr/libexec/mysql56/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13 - Permission denied)
    2017-05-06 04:31:30 6516 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it.
    2017-05-06 04:31:30 6516 [Note] InnoDB: Using atomics to ref count buffer pool pages
    2017-05-06 04:31:30 6516 [Note] InnoDB: The InnoDB memory heap is disabled
    2017-05-06 04:31:30 6516 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
    2017-05-06 04:31:30 6516 [Note] InnoDB: Memory barrier is not used
    2017-05-06 04:31:30 6516 [Note] InnoDB: Compressed tables use zlib 1.2.8
    2017-05-06 04:31:30 6516 [Note] InnoDB: Using Linux native AIO
    2017-05-06 04:31:30 6516 [Note] InnoDB: Using CPU crc32 instructions
    ^G/usr/libexec/mysql56/mysqld: Can't create/write to file '/var/tmp/ibdSw66G' (Errcode: 13 - Permission denied)
    2017-05-06 04:31:30 7faa567fd840  InnoDB: Error: unable to create temporary file; errno: 13
    2017-05-06 04:31:30 6516 [ERROR] Plugin 'InnoDB' init function returned error.
    2017-05-06 04:31:30 6516 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
    2017-05-06 04:31:30 6516 [ERROR] Unknown/unsupported storage engine: InnoDB
    2017-05-06 04:31:30 6516 [ERROR] Aborting
2017-05-06 04:31:30 6516 [Note] Binlog end
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'partition'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'ARCHIVE'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_DATAFILES'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_TABLESPACES'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN_COLS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_FOREIGN'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_FIELDS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_COLUMNS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_INDEXES'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_TABLESTATS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_SYS_TABLES'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_FT_INDEX_TABLE'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_FT_INDEX_CACHE'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_FT_CONFIG'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_FT_BEING_DELETED'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_FT_DELETED'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_FT_DEFAULT_STOPWORD'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_METRICS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_BUFFER_POOL_STATS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE_LRU'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_BUFFER_PAGE'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX_RESET'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_CMP_PER_INDEX'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_CMPMEM_RESET'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_CMPMEM'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_CMP_RESET'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_CMP'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_LOCK_WAITS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_LOCKS'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'INNODB_TRX'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'PERFORMANCE_SCHEMA'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'BLACKHOLE'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'CSV'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'MEMORY'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'MyISAM'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'MRG_MYISAM'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'sha256_password'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'mysql_old_password'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'mysql_native_password'
2017-05-06 04:31:30 6516 [Note] Shutting down plugin 'binlog'
2017-05-06 04:31:30 6516 [Note] /usr/libexec/mysql56/mysqld: Shutdown complete

EDIT

I also fully uinstalled and re-installed mysql with this command couple of times now:

sudo yum -y remove mysql-server
sudo yum -y install mysql-server

EDIT

Alright, forget it...lol. I just started a new amz ec2 linux instance. THanks!

Solution

'./mysql/plugin.frm' (errno: 13 - Permission denied)

Can't create/write to file '/var/tmp/ibdSw66G ... Permission denied'

Try chown mysql.mysql /var/lib/mysql/ -R; chmod 1777 /var/tmp Also, have you read/tried this:

Can't open the mysql.plugin table. Please run mysql_upgrade to create it.

Comments

[Putnik]

what's the error message after start? what's in netstat -plnt | grep 3306 ?

[Admin]

when i type above command without sudo i get: (No info could be read for "-p": geteuid()=500 but you should be root.). And when i type with sudo, i get nothing, just goes to next commandline.

[Admin]

nope still same issue. and telnet is not found a recognized command on my server.

[Admin]

tried that, still doesn't work.

[Kumaresh Babu N S]

@Dave2345 Have you opened inbound traffic for Port 3306?

[AlexD]

The correct permissions for /var/tmp should be 1777.

[Dave2345]

Yes, in AWS console I set it.

[Dave2345]

I couldn't change permissions/owners of either directories because of "permission denied" error(s).

[Putnik]

@Dave2345 so does it work now?

[Dave2345]

no, i just trashed this instance and started another one lol. thanks tho.