Apache Tomcat is one of the most popular servlet containers for running Java web applications. In this guide, we’ll walk through the installation process on an Amazon EC2 Linux instance, step by step.

✅ Prerequisites:

Before starting, make sure you have:
• Java 1.8 or above (Tomcat 9.x requires at least Java 8; Java 21 works too).
• 1 GB RAM (sufficient for small web applications).
• Linux server (Amazon EC2 is a common choice).

🖥️ Step-by-Step Installation:

Step 1: Launch EC2 Instance
• Create an EC2 machine (Amazon Linux or CentOS recommended).
• Connect to it via SSH.
Step 2: Connect to the Server –> ssh -i your-key.pem ec2-user@<public-ip>

Step 3: Switch to Root User –> sudo su –

Step 4: Install Java
Search for available Java versions –> sudo yum search java | grep OpenJDK,java -version,sudo yum install java-21-openjdk-devel -y

Step 5: Install Required Utilities –>yum install wget unzip tree -y

Step 6: Download Tomcat
Navigate to /opt/ directory –>cd /opt/

wget https://dlcdn.apache.org/tomcat/tomcat-9/v9.0.109/bin/apache-tomcat-9.0.109.zip(use ooficial website for latest links)

Step 7: Extract Tomcat –>unzip apache-tomcat-9.0.109.zip

Step 8: Navigate to bin/ Directory –> cd /opt/apache-tomcat-9.0.109/bin

Step 9: Make Scripts Executable –> chmod u+x *.sh (This ensures startup and shutdown scripts can be executed)

A. ./startup.sh

B. ./shutdown.sh

Note : If you want to start/stop tomcat server from anywhere instead of bin dir?

ln -s /opt/apache-tomcat-9.0.109/bin/startup.sh /usr/bin/startTomcat
ln -s /opt/apache-tomcat-9.0.109/bin/shutdown.sh /usr/bin/stopTomcat

Now you can go and run in any directory.

Access Tomcat in your browser at –> http://<EC2-public-ip>:8080

🧭 Conclusion

With these steps, you’ve successfully installed Apache Tomcat on an EC2 Linux instance. From here, you can deploy your .WAR files into the WEBAPPS/ directory and start serving Java web applications.

Accessing Tomcat Manager & Host Manager:

Even after enabling port 8080, you may find that Server Status, Manager App, and Host Manager are not accessible. This is because Tomcat restricts access by default. You need to configure it.

🔹 Manager App Configuration

1. Navigate to the manager app directory –> cd /opt/apache-tomcat-9.0.109/webapps/manager/META-INF –> vi context.xml –> Comment out the 21st and 22nd lines (which restrict access) –>Refresh the Tomcat main page → it will now ask for credentials –> Add users in tomcat-users.xml (cd /opt/apache-tomcat-9.0.109/conf/
vi tomcat-users.xml –>

<user username=”yourusername” password=”password” roles=”manager-gui,admin-gui”/>

<user username=”mahesh” password=”password” roles=”manager-gui,admin-gui”/> )

Host Manager Configuration:

Follow the same process for Host Manager:
1. Navigate to host-manager directory –>cd /opt/apache-tomcat-9.0.109/webapps/host-manager/META-INF  –> Edit and comment out the restricted lines –> Refresh the page → enter the credentials you added in tomcat-users.xml

Verify Logs:

Finally, check the logs to confirm everything is working

cd /opt/apache-tomcat-9.0.109/logs

Here you’ll find files like:

catalina.log

localhost.log

manager.log

host-manager.log

🎯 Conclusion

By enabling port 8080 in your EC2 security group and configuring Tomcat Manager/Host Manager, you can securely access and manage your Tomcat server from your PC. This setup allows you to deploy applications, monitor server status, and manage hosts directly through the Tomcat web interface.

🔄 How to Change Tomcat Port Number (and Why It’s Needed)

When running multiple applications on the same server, port conflicts are a common issue. By default, Apache Tomcat runs on port 8080. But what if another application—like Jenkins—also uses port 8080? You’ll run into a conflict and see errors such as ” java.net.BindException: Address already in use ” To resolve this, you need to change the port number for one of the applications.

⚠️ Why Change the Port Number?

• Tomcat default port: 8080
• Jenkins default port: 8080
• Running both on the same server → port conflict.
• Solution: Assign a different port (e.g., Tomcat on 8081, Jenkins stays on 8080).

🛠️ Steps to Change Tomcat Port Number
Step 1: Go to the Configuration Directory –> cd /opt/apache-tomcat-9.0.109/conf

Step 2: Edit server.xml –> vi server.xml –> Locate the Connector element (around line 71) –> <Connector port=”8080″ protocol=”HTTP/1.1″
connectionTimeout=”20000″
redirectPort=”8443″ />

Change the port number (example: 8081) –> <Connector port=”8081″ protocol=”HTTP/1.1″
connectionTimeout=”20000″
redirectPort=”8443″ />

Restart Tomcat :

./shutdown.sh
./startup.sh

Access with New Port –> http://:8081

🎯 Conclusion:

Changing Tomcat’s port number is essential when running multiple services like Tomcat and Jenkins on the same server. By editing , you can easily avoid conflicts and keep both applications running smoothly.