mysqladmin is used to run commands against mysqld daemon
XREF to this doc for info: http://www.ewhathow.com/2013/09/how-to-check-if-mysql-server-is-running-on-linux/
XREF to this MariaDB doc: https://mariadb.com/kb/en/mariadb/mysqladmin/
Q: How to check if MySQL Process is running?
A: ps aux | grep mysql
mysql     9555  0.0  7.2 774240 133436 ?       Ssl  14:17   0:02 /usr/sbin/mysq d
paul      9713  0.0  0.2 162420  4212 pts/0    T    15:02   0:00 mysql -u root -p
root      9812  0.0  0.0 112640   964 pts/0    S+   15:29   0:00 grep –color=auto mysql
Note: ERROR! MySQL is running but PID file could not be found
Q: Logged in as root, is mysqladmin running?
A: mysqladmin status
Note: mysqladmin: connect to server at ‘localhost’ failed
error: ‘Access denied for user ‘root’@’localhost’ (using password: NO)’
Note: Issue is that syntax requires authentication
Q: How to check mysqladmin running?
A: mysqladmin -u root -p status (Note: Enter password I have for database system)
Uptime: 4748  Threads: 2  Questions: 27  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.005
Q: As an experiment, stop the SQL service, check for mysqladmin running, start the service again
A: sudo systemctl stop mariadb.service
A: mysqladmin -u root -p status
Note: mysqladmin: connect to server at ‘localhost’ failed
error: ‘Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (2 “No such file or directory”)’
Check that mysqld is running and that the socket: ‘/var/lib/mysql/mysql.sock’ exists!
A: sudo systemctl start mariadb.service
A: mysqladmin -u root -p status
Note: Uptime: 7  Threads: 1  Questions: 1  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.142
Summary: Output of “mysqladmin status” will give a definite answer on whether the MySQL service is running.
Q: How to check status of mysql service (because I’m using CentOS)
A: service mysql status
Note: ERROR! MySQL is running but PID file could not be found
Note: Instructions within here to fix this: http://geeksterminal.com/fix-mysql-is-running-but-pid-file-could-not-be-found-error/342/
Q: What is the PID file that it was referring to?
Q: What happens when I enter: mysqladmin -u root -p (and enter the database system password)?
mysqladmin  Ver 9.1 Distrib 10.1.8-MariaDB, for Linux on x86_64
Copyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.
Administration program for the mysqld daemon.
Usage: mysqladmin [OPTIONS] command command….
Default options are read from the following files in the given order:
/etc/my.cnf ~/.my.cnf
The following groups are read: mysqladmin client client-server client-mariadb
The following options may be given as the first argument:
–print-defaults        Print the program argument list and exit.
–no-defaults           Don’t read default options from any option file.
–defaults-file=#       Only read default options from the given file #.
–defaults-extra-file=# Read this file after the global files are read.
  -c, –count=#       Number of iterations to make. This works with -i
                      (–sleep) only.
  –debug-check       Check memory and open file usage at exit.
  –debug-info        Print some debug info at exit.
  -f, –force         Don’t ask for confirmation on drop database; with
                      multiple commands, continue even if an error occurs.
  -C, –compress      Use compression in server/client protocol.
  –character-sets-dir=name
                      Directory for character set files.
  –default-character-set=name
                      Set the default character set.
  -?, –help          Display this help and exit.
  -h, –host=name     Connect to host.
  -b, –no-beep       Turn off beep on error.
  -p, –password[=name]
                      Password to use when connecting to server. If password is
                      not given it’s asked from the tty.
  -P, –port=#        Port number to use for connection or 0 for default to, in
                      order of preference, my.cnf, $MYSQL_TCP_PORT,
                      /etc/services, built-in default (3306).
  –protocol=name     The protocol to use for connection (tcp, socket, pipe,
                      memory).
  -r, –relative      Show difference between current and previous values when
                      used with -i. Currently only works with extended-status.
  -s, –silent        Silently exit if one can’t connect to server.
  -S, –socket=name   The socket file to use for connection.
  -i, –sleep=#       Execute commands repeatedly with a sleep between.
  –ssl               Enable SSL for connection (automatically enabled with
                      other flags).
  –ssl-ca=name       CA file in PEM format (check OpenSSL docs, implies
                      –ssl).
  –ssl-capath=name   CA directory (check OpenSSL docs, implies –ssl).
  –ssl-cert=name     X509 cert in PEM format (implies –ssl).
  –ssl-cipher=name   SSL cipher to use (implies –ssl).
  –ssl-key=name      X509 key in PEM format (implies –ssl).
  –ssl-crl=name      Certificate revocation list (implies –ssl).
  –ssl-crlpath=name  Certificate revocation list path (implies –ssl).
  –ssl-verify-server-cert
                      Verify server’s “Common Name” in its cert against
                      hostname used when connecting. This option is disabled by
                      default.
  -u, –user=name     User for login if not current user.
  -v, –verbose       Write more information.
  -V, –version       Output version information and exit.
  -E, –vertical      Print output vertically. Is similar to –relative, but
                      prints output vertically.
  -w, –wait[=#]      Wait and retry if connection is down.
  –connect-timeout=#
  –shutdown-timeout=#
  –plugin-dir=name   Directory for client-side plugins.
  –default-auth=name Default authentication client-side plugin to use.
Variables (–variable-name=value)
and boolean options {FALSE|TRUE}  Value (after reading options)
——————————— —————————————-
count                             0
debug-check                       FALSE
debug-info                        FALSE
force                             FALSE
compress                          FALSE
character-sets-dir                (No default value)
default-character-set             auto
host                              (No default value)
no-beep                           FALSE
port                              0
relative                          FALSE
socket                            (No default value)
sleep                             0
ssl                               FALSE
ssl-ca                            (No default value)
ssl-capath                        (No default value)
ssl-cert                          (No default value)
ssl-cipher                        (No default value)
ssl-key                           (No default value)
ssl-crl                           (No default value)
ssl-crlpath                       (No default value)
ssl-verify-server-cert            FALSE
user                              root
verbose                           FALSE
vertical                          FALSE
connect-timeout                   43200
shutdown-timeout                  3600
plugin-dir                        (No default value)
default-auth                      (No default value)
Where command is a one or more of: (Commands may be shortened)
  create databasename     Create a new database
  debug                   Instruct server to write debug information to log
  drop databasename       Delete a database and all its tables
  extended-status         Gives an extended status message from the server
  flush-all-statistics    Flush all statistics tables
  flush-all-status        Flush status and statistics
  flush-client-statistics Flush client statistics
  flush-hosts             Flush all cached hosts
  flush-index-statistics  Flush index statistics
  flush-logs              Flush all logs
  flush-privileges        Reload grant tables (same as reload)
  flush-slow-log          Flush slow query log
  flush-status            Clear status variables
  flush-table-statistics  Clear table statistics
  flush-tables            Flush all tables
  flush-threads           Flush the thread cache
  flush-user-statistics   Flush user statistics
  kill id,id,…        Kill mysql threads
  password [new-password] Change old password to new-password in current format
  old-password [new-password] Change old password to new-password in old format
  ping                  Check if mysqld is alive
  processlist           Show list of active threads in server
  reload                Reload grant tables
  refresh               Flush all tables and close and open logfiles
  shutdown              Take server down
  status                Gives a short status message from the server
  start-slave           Start slave
  stop-slave            Stop slave
  variables             Prints variables available
  version               Get version info from server
Q: Why do I have to enter the password each time I run a mysqladmin command?
A: Because that’s the way it is
Note:  mysqladmin -u root -p ping — responds with “mysqld is alive”, but I have to enter password each time
Q: What are some mysqladmin commands I can play with?
A: http://www.tecmint.com/mysqladmin-commands-for-database-administration-in-linux/
Q: How to change the password for root?
A: mysqladmin -u root -p123456 password ‘xyz123’
Note: p123456 was old password and xyz123 is new
Q: How to check if MariaDB/MySQL is running?
A:  mysqladmin -u root -p ping
Note: Comes back with, “mysqld is alive”
Q: How to check which version of MariaDB is running?
A:  mysqladmin -u root -p version
mysqladmin  Ver 9.1 Distrib 10.1.8-MariaDB, for Linux on x86_64
Copyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.
Server version          10.1.8-MariaDB
Protocol version        10
Connection              Localhost via UNIX socket
UNIX socket             /var/lib/mysql/mysql.sock
Uptime:                 16 hours 46 min 1 sec
Threads: 1  Questions: 8  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.000
Q: How to check status of server, so see threads?
A: mysqladmin -u root -p status
Uptime: 60501  Threads: 1  Questions: 9  Slow queries: 0  Opens: 0  Flush tables: 1  Open tables: 11  Queries per second avg: 0.000
Q: How to check all the running processes?
A: mysqladmin -u root -p processlist
+—-+——+———–+—-+———+——+——-+——————+———-+
| Id | User | Host      | db | Command | Time | State | Info             | Progress |
+—-+——+———–+—-+———+——+——-+——————+———-+
| 19 | root | localhost |    | Query   | 0    | init  | show processlist | 0.000    |
+—-+——+———–+—-+———+——+——-+——————+———-+
Q: How to create a database?
A: mysqladmin -u root -p create databasename
Q: How to show databases
A: First, go into MariaDB Monitor with – mysql -u root -p
A: show databases;
— +——————–+
| Database           |
+——————–+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+——————–+
4 rows in set (0.00 sec)
Q: How to Drop (AKA Delete, including all tables) a database?  This should be done with caution as the data is destroyed.
A: mysqladmin -u root -p drop databasename
Q: How to shutdown MariaDB safely?
A:  mysqladmin -u root -p shutdown
Q: Another way of how to shutdown MariaDB?
A: sudo systemctl stop mariadb.service
Q: How to start a server?
A: sudo systemctl start mariadb.service
Q: How to kill a sleeping process?
A: First, find the current processes with — mysqladmin -u root -p processlist
A: mysqladmin -u root -p kill 5,10
Note: The Process ID’s are 5 and 10 — if multiple processes you separate with a comma
Q: How to run multiple commands at same time?
A: mysqladmin -u root -p status version ping
Note: Put a space between each command