Debugging a Cloud Deployment Issue

Overview

This documentation provides a walkthrough for debugging an HTTP Error 500 encountered on a web server named ws01 deployed in the cloud. The task involves identifying and resolving the issue to restore the web service to a healthy state.

Introduction

As an IT administrator, encountering server errors is a common challenge. This task focuses on the hands-on process of diagnosing a server error and applying the necessary fixes to bring a web service back online.

Steps to Debug the Issue

1. Identify the Error:

   • Access the web server ws01 via its external IP address to confirm the HTTP Error 500.
   • Understanding HTTP status codes is crucial for pinpointing the nature of the issue.

2. Inspect the Web Server Status:

   • Use the systemctl command to check the status of the Apache service:

     sudo systemctl status apache2
     

   • Look for any error messages in the service status output that indicate why the service might have failed.

3. Troubleshooting:

   • Inspect error logs or use the journalctl command to find detailed error messages.
   • If port conflicts are detected, identify which processes are binding to the conflicting ports using the netstat command:

     sudo netstat -nlp
     

   • Identify rogue processes (e.g., a Python test script) that should not be running on the production port.

4. Resolve Port Conflicts:

   • Terminate any unauthorized processes using the kill command.
   • If a rogue service is found, stop and disable it using:

     sudo systemctl stop [service-name] && sudo systemctl disable [service-name]
     

   • Verify that the port is now free and no unauthorized services are running.

5. Restart the Web Server:

   • Once the port conflict is resolved, restart the Apache service:

     sudo systemctl start apache2
     

   • Refresh the web browser to check if the service is back up and running.

Resolution

Upon following these steps, the ws01 web server should be back online, serving the default Apache2 Ubuntu page instead of the HTTP Error 500.

Conclusion

The process detailed above highlights the practical skills needed to debug a live web server issue in a cloud environment. By following systematic troubleshooting steps, the web server was successfully recovered and returned to operational status.