We are talking about 2 different computers, but it depends on what role either of them is playing. Both can either be a program on a computer or the computer itself.
one of them sends a request which is the "client" while the other receives and processes the request which is the "server".
Example: Just like when you browse in the internet. The browser itself is the "client". The program or the software like "Google chrome" is the "client".
Then the "server" will be the website that you are actually trying to access like (facebook).
For example: You go to your browser and type www.ogechukwu.com. it means that your browser is considered the "client". it is sending request to the remote server and in turn would be expecting some kind of response from the remote server.
Your terminal will be the "client" while www.ogechukwu.com will be the "server".
The client/server model
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server -- the central database management program.
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client -- program connect to the server to retrieve or modify data.
A diagram of web client-server architecture.
A diagram of web client-server with database.
Implement a client-server architecture using MySQL Database Management System. (DBMS)
Spin up two virtual server (Ec2 instances in AWS) and name them: "mysql-server" and "mysql-client".
Then We connect to the instances from two seperate ubuntu terminal.
After connecting to the instances on each of the terminals, we edit the /etc/hostname/ file to change the names of each of the server so as to align with the given name on the instance i.e client and server respectively. We do this using the command:
$ sudo hostname server
$ sudo hostname client
Then we refresh the terminal for the changes to reflect.
Results:
On the server and client terminals we run the command.
$ sudo apt update
Results:
We install mysql-server software on the "server" terminal.
$ sudo apt install mysql-server
Results:
We install mysql-client software on the "client" terminal.
Results:
We verify the status of mysql.
$ sudo systemctl status mysql
Results:
By default, both of your EC2 virtual servers are located in the same local virtual network, so they can communicate to each other using local IP addresses. Use mysql server's local IP address to connect from mysql client. MySQL server uses TCP port 3306 by default, so you will have to open it by creating a new entry in ‘Inbound rules’ in ‘mysql server’ Security Groups. For extra security, do not allow all IP addresses to reach your ‘mysql server’ – allow access only to the specific local IP address of your ‘mysql client’.
Results:
You might need to configure mysql server to allow connections from my remote hosts.
$ sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf
Replace this blind-address = 127.0.0.1 to this blind-address = 0.0.0.0.
Results:
In your mysql-server ec2 instance allow the ip address of the mysql-client ec2 instance with port 3306 to access the mysql-server ec2 instance.
curl http://checkip.amazonaws.com
Results:
Note: '18.144.9.57' is the ip address of mysql-client.
set up mysql database in server that the client will be able to connect to:
$ sudo mysql
It will take us into the mysql database.
Results:
Next we run:
Then exit and start interactive script.
We put in the password we specified earlier (Okekeoge@1).To create a validated password, type y. Then choose the strength of the new password you want to create, we put in the new password.
Results:
log into mysql console
$ sudo mysql -p
Result:
Create a new database
$ mysql> CREATE DATABASE test_database;
then create a new user and grant him privilege on the database u just created.
mysql> CREATE USER 'ogechukwu'@'%' IDENTIFIED WITH mysql_native_password BY 'Okekeoge@1';
Give the user ("ogechukwu") permission over the 'test_database' database.
mysql> GRANT ALL ON test_database.* TO 'ogechukwu'@'%';
Then we exit.
Let's test if the new user has the proper permission by logging into mysql console.
mysql -u ogechukwu -p
And put in the password you created
Okekeoge@1
We then go to our client terminal and connect to the mysql server database remotely without using SSH.
$ mysql -u ogechukwu -h <IP-address of the server> -p
we put in our password and run this command:
mysql> SHOW DATABASES;
Result:
