README.md

CAT 3

Alejandro Pérez Bueno Jan 03, 2024

• Exercise 1
  • Basic VM configuration
  • Set up web service
• Exercise 2
  • Basic VM configuration
  • Frontend setup
  • Workers setup
  • Testing the results
• Exercise 3
  • AWS VM configuration
  • WordPress installation
  • WordPress setup
  • WordPress performance
• Conclusion
• Annexes



Exercise 1

Basic VM configuration

First and foremost, it is necessary to create the EC2 instance that will host our web service, named caa3-ami-1 with the tag aperez-b.

See Figure 1 for more details.

We can then connect to it via ssh from our machine with the private key we downloaded in the creation screen, as follows:

chmod 400 ~/.ssh/keypair-aperez-b.pem
ssh -i ~/.ssh/keypair-aperez-b.pem ec2-user@ec2-3-94-211-15.compute-1.amazonaws.com

Note

In order to properly connect to the remote instance, I had to change the default routing table to allow connection with the internet.

To configure the VM with minimal configuration, one must do the following:

sudo yum update -y
sudo yum upgrade -y
sudo hostnamectl set-hostname aperez-b-master
sudo yum install httpd -y
sudo systemctl enable --now httpd

Lines 1-2
Update the system.

Line 3
Set hostname to aperez-b-master.

Lines 4-5
Install and set up httpd.

Now everything has been set up.

Set up web service

Note

I used the HTML equivalent to the submission I worked on for CAA 2

First, copy the website and its files to the /var/www/html directory:

cp README.html /var/www/html/index.html
cp -r README_files/ /var/www/html/
cp -r img /var/www/html/

Line 1
Main HTML file.

Line 2
Extra files from quarto to make the website pretty.

Line 3
Images from screenshots I took in the previous CAA.

At this point our website is up and running at http://ec2-3-94-211-15.compute-1.amazonaws.com. We can check that it is working with JMeter (see Figure 2 (a)).

You can also simply open a browser on your local machine and enter the IP of the Remote (see Figure 2 (b)).



Exercise 2

Basic VM configuration

Warning

The VM from the previous exercise will NOT be reused in this one.

Three VMs have to be configured:

1. A machine called frontend with a private and a public NIC.
2. A machine called worker1 with a private NIC.
3. A machine called worker2 with a private NIC.

On all of them, we have to do the following:

• Update packages and install httpd.
• Set hostname following the same scheme as in the prior exercise.
• Worker VMs will be called aperez-b-worker1 and aperez-b-worker2.

Here is an example of the code ran on worker1:

sudo hostnamectl set-hostname aperez-b-worker1
sudo yum update -y
sudo yum upgrade -y
sudo yum install httpd -y
sudo systemctl enable --now httpd

Frontend setup

Create the configuration file /etc/httpd/conf.d/balancer.conf adding the following lines:

<VirtualHost *:80>
    ServerName ec2-18-210-13-85.compute-1.amazonaws.com
    ProxyPreserveHost On
    <Proxy balancer://mycluster>
        BalancerMember http://172.31.6.227:80
        BalancerMember http://172.31.6.197:80
        ProxySet lbmethod=byrequests # or ProxySet lbmethod=bytraffic
    </Proxy>
    <Location /balancer-manager>
        SetHandler balancer-manager
    </Location>
    ProxyPass /balancer-manager !
    ProxyPass / balancer://mycluster/
    ProxyPassReverse / balancer://mycluster/
</VirtualHost>

This configuration sets a balancer for the two websites hosted on the worker VMs with a certain balancer algorithm and also enables the use of the balancer-manager extension.

Workers setup

Copy the different websites and their necessary files to each of the worker VMs’ /var/www/html directory. For this I picked the following:

• For worker1 VM: Same site from the previous exercise.
• For worker2 VM: Similar site from another project.

Testing the results

Once all 3 VMs are up and running, let’s make sure that they all three have the httpd service started and updated to the latest changes made in the configuration files. To do so, we will restart the server:

systemctl enable httpd
systemctl restart httpd

See Figure 6 to verify that the websites are served properly from the frontend.

Then, using ab we can benchmark the two balancing algorithms we are to compare:

• byrequests: distributes traffic evenly to every worker. In this case it would be 50/50.
• bytraffic: distributes the workload based on the load of each worker.

We will compare the two algorithms by running the following command:

ab -n 100 -c 10 <FrontendPublicIP>/

• ab: The same apache utility used in exercise 1.
• -n 100: number of petitions made to the server.
• -c 10: number of concurrent requests made to the server at a time.

As can be seen in the screenshots from Figure 3, bytraffic is more efficient at distributing higher workloads, since fewer requests are lost when compared to the byrequests algorithm.

You can also verify that the balancer located at http://<FrontendPublicIP>/balancer-manager is working (see Figure 4), and that both sites are served in the frontend (see Figure 5).



Exercise 3

AWS VM configuration

For this last part I merely followed the 5-module tutorial from the post Deploy WordPress with Amazon RDS carefully to properly install and configure WordPress.

See Figure 7 to check the settings of EC2 and RDS after following the aforementioned tutorial.

WordPress installation

See Figure 8 to see how the WordPress site looked before and after setting up the database and the Wordpress app itself.

Note

At first, I could not upload anything to the media section of the WordPress app. Turns out I was lacking permissions to write in the specific directory. To fix it, I ran the following command from ssh:

sudo chown -R apache:apache /var/www/html/

WordPress setup

After configuring the database and the VM, it is time to log in with a new WordPress user. In my case I created a new user aperez-b with my UOC email address and started adding blog posts to the site. I added a total of six entries, with various types of content and media. Some have lists, images, links, quotes, video, audio, and so on (see Figure 10).

Note

As it is hard to show the WordPress site with just screenshots, I recorded a short video showcasing every post (thus proving that it all works as expected)

WordPress performance

See Figure 9 to view the result of the test performed by PageSpeed Insights.

Warning

In Figure 9, the url appears to be different from all other screenshots from this exercise. This is because I had to enable the site to be accessed by anyone (at first I had set it up so that only my IP could access the website), and as a result a new Public IP address was assigned



Conclusion

In this CAA I have worked with AWS for the first time, and I cannot say it was a piece of cake. Nevertheless, it was a fun journey.The overall experience of working with it to deploy applications has been a valuable learning opportunity. By understanding the technologies for the deployment of cloud computing infrastructures securely and efficiently, I was able to deploy a balanced proxy using Apache2 with a front-end and two workers, as well as a full-fledged WordPress server. Overall, the experience has provided me with a solid foundation in cloud computing that I can build upon in future projects.



Annexes

Figure 2: Website running on browser and in JMeter

Figure 3: Test the command ab -n 100 -c 10 <FrontendPublicIP> with two balancing algorithms

Figure 5: Pages served by each worker balanced from the frontend

Figure 7: EC2 and RDS configuration

Figure 8: WordPress pre-setup and post-setup