Explanation:

To uninstall PHP

sudo apt-get remove –purge php*
sudo apt-get purge php*
sudo apt-get autoremove
sudo apt-get autoclean
sudo apt-get remove dbconfig-php
sudo apt-get dist-upgrade
Note: The output of the below command will provide you with information the installed package software, version, architecture and short description about the package. grep command is used to find the PHP package
sudo dpkg --get-selections | grep php | cut -f 1
sudo apt-get remove --purge <package name from the previous command output>
sudo whereis php
sudo rm -rf <directory/file path from the previous command output>

To uninstall Apache

sudo service apache2 stop
sudo apt-get purge apache2 apache2-utils apache2.2-bin apache2-common
sudo apt-get autoremove
The output of the below command will provide you with information the installed package software, version, architecture and short description about the package. grep command is used to find the MySQL package
sudo dpkg --get-selections | grep apache | cut -f 1
sudo apt-get remove --purge <package name from the previous command output>
sudo whereis apache
sudo rm -rf <directory/file path from the previous command output>

To uninstall MySQL

sudo apt-get remove –purge mysql*
sudo apt-get purge mysql*
sudo apt-get autoremove.
sudo apt-get autoclean.
sudo apt-get remove dbconfig-php.
sudo apt-get dist-upgrade.
The output of the below command will provide you with information the installed package software, version, architecture and short description about the package. grep command is used to find the MySQL package
sudo dpkg --get-selections | grep mysql | cut -f 1
sudo apt-get remove --purge <package name from the previous command output>
sudo whereis mysql
sudo rm -rf <directory/file path from the previous command output>

Explanation:

The mention exception occurred while granting privileges to the MySQL instance database.

Exception:

mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'10.0.1.14';
ERROR 1045 (28000): Access denied for user 'root'@'10.0.1.14' (using password: YES)

Solution:

Login to the data tier where MYSQL server --> Login to MYSQL --> Execute the following steps.

• Grant privileges to root@10.0.1.14 

        ubuntu@ip-10-0-2-227:~$ sudo mysql -u root -p

        mysql> select current_user();
        +----------------+
        | current_user() |
        +----------------+
        | root@localhost |
        +----------------+
        1 row in set (0.00 sec)

        mysql> SELECT host,user,Grant_priv,Super_priv FROM mysql.user where user = 'root';
        +-----------+------+------------+------------+
        | host | user | Grant_priv | Super_priv |
        +-----------+------+------------+------------+
        | localhost | root | Y | Y |
        | 10.0.1.14 | root | N | Y |
        +-----------+------+------------+------------+
        2 rows in set (0.00 sec)

        mysql> UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';
        Query OK, 1 row affected (0.00 sec)
        Rows matched: 2 Changed: 1 Warnings: 0

        mysql> SELECT host,user,Grant_priv,Super_priv FROM mysql.user where user = 'root';
        +-----------+------+------------+------------+
        | host | user | Grant_priv | Super_priv |
        +-----------+------+------------+------------+
        | localhost | root | Y | Y |
        | 10.0.1.14 | root | Y | Y |
        +-----------+------+------------+------------+
        2 rows in set (0.00 sec)

        mysql> FLUSH PRIVILEGES;
        Query OK, 0 rows affected (0.00 sec)

• Try again

        mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'10.0.1.14';

Explanation:

The mention exception occurred while connecting to MySQL database instance remotely.

Exception:

ubuntu@ip-10-0-1-14:~$ sudo mysql -u root -p -h 10.0.2.227
Enter password:
ERROR 1130 (HY000): Host '10.0.1.14' is not allowed to connect to this MySQL server

Solution:

Login to the data tier where MYSQL server --> Login to MYSQL --> Execute the following steps.

• Create and Grant all privileges to root@10.0.1.14  for remote login

        ubuntu@ip-10-0-2-227:~$ sudo mysql -u root -p

        mysql> SELECT host FROM mysql.user WHERE User = 'root';
        +-----------+
        | host |
        +-----------+
        | localhost |
        +-----------+
        1 row in set (0.00 sec)

        mysql> CREATE USER 'root'@'10.0.1.14' IDENTIFIED BY '*****';
        Query OK, 0 rows affected (0.00 sec)

        mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'10.0.1.14';
        Query OK, 0 rows affected (0.00 sec)

        mysql> FLUSH PRIVILEGES;
        Query OK, 0 rows affected (0.00 sec)

        mysql> SELECT host FROM mysql.user WHERE User = 'root';
        +-----------+
        | host |
        +-----------+
        | 10.0.1.14 |
        | localhost |
        +-----------+
        2 rows in set (0.00 sec)

• Try again

         ubuntu@ip-10-0-1-14:~$ sudo mysql -u root -p -h 10.0.2.227

Explanation:

The mention exception occurred while connecting to MySQL database instance remotely.

Exception:

ubuntu@ip-10-0-1-14:~$ sudo mysql -u root -p -h 10.0.2.227
Enter password:
ERROR 2003 (HY000): Can't connect to MySQL server on '10.0.2.227' (111)

Solution:

Login to the data tier where MYSQL server --> Login to MYSQL --> Execute the following steps.

• Comment the bind-address       

        ubuntu@ip-10-0-2-227:~$ sudo mysql -u root -p
        ubuntu@ip-10-0-2-227:~$ more /etc/mysql/mysql.cnf

        !includedir /etc/mysql/conf.d/
        !includedir /etc/mysql/mysql.conf.d/

        Note: Search for bind-address = 127.0.0.1. in /etc/mysql/mysql.cnf. If not found, search for bind-address = 127.0.0.1 in the files under included directories(!includedir).

        ubuntu@ip-10-0-2-227:~$ sudo vi /etc/mysql/mysql.conf.d/mysqld.cnf

        Comment the bind-address as follows
        # bind-address = 127.0.0.1

        Save the /etc/mysql/mysql.conf.d/mysqld.cnf file

• Restart mysql to load the recent configuration

        ubuntu@ip-10-0-2-227:~$ sudo systemctl restart mysql
        ubuntu@ip-10-0-2-227:~$ sudo systemctl status mysql
        ● mysql.service - MySQL Community Server
         Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: en
        Active: active (running) since Wed 2019-08-21 18:31:49 UTC; 13s ago
        Process: 15835 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/m
        Process: 15813 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exi
        Main PID: 15837 (mysqld)
        Tasks: 27 (limit: 1152)
        CGroup: /system.slice/mysql.service
        ─15837 /usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/mysqld.pi

• Try again

         ubuntu@ip-10-0-1-14:~$ sudo mysql -u root -p -h 10.0.2.227