All courses
Resource hub
Featured resource
Tech Upskilling Playbook 2025
Tech Upskilling Playbook

Build future-ready tech teams and hit key business milestones with seven proven plays from industry leaders.

Learn more
Hamburger Icon
  • Labs icon Lab
  • Cloud
Google Cloud Platform icon
Labs

Enable Verbose Garbage Collection

Welcome to this hands-on lab, where we will set Tomcat up to use verbose garbage collection. As part of this lab you will also enable parallel garbage collection. It is useful to have verbose garbage collection set, to help you troubleshoot your Tomcat instance and its applications. We are using Apache's Tomcat, a Java-based application platform built around deploying and managing Java Web Applications. The server provided in this lab environment is running Red Hat Enterprise 8 and has Tomcat 9 pre-installed for you. The Tomcat instance is available on port **8080**.

Get started Contact sales
Google Cloud Platform icon
Labs

Path Info

Level
Clock icon Intermediate
Duration
Clock icon 45m
Last updated
Clock icon Aug 29, 2025

Contact sales

By filling out this form and clicking submit, you acknowledge our privacy policy.

Table of Contents

  1. Challenge

    Test to Ensure You Can Access the Preconfigured Tomcat Instances on Port 8080

    Use the Tomcat server's public IP address and port 8080. Connect to the Tomcat GUI and log in. The username and password to use are the same as what's provided for CLI access.

    To access the server, copy the external IP address and test in your browser by using this IP address and appending the :8080 to it.

    For example, if an IP address shown was 3.92.152.3, then you would put the following into your web browser:

    http://3.92.152.3:8080

    You should see the GUI.

    Note: It may take from 3 to 10 mins after the Hands-On Lab has started before you can access the Tomcat servers on Port 8080.

  2. Challenge

    Configure Tomcat to Use Verbose and Parallel Garbage Collection

    You will need to set options for Tomcat's startup routine so that it uses verbose and parallel garbage collection.

    The options to add to the Tomcat startup file (you may need to create the file) are the following:

    • Verbose garbage collection: 
      -verbose:gc
    • Parallel Garbage collection: 
      -XX:-UseParallelGC

    These entries should be exported as CATALINA_OPTS.

  3. Challenge

    Restart Tomcat and Monitor the Logs for GC Messages

    Restart the Tomcat server.

    Check the Tomcat logs for entries relating to garbage collection. The log to look into is the catalina.out log.

    An example verbose log entry might look like the following:

    [2.536s][info][gc] GC(0) Pause Young (Allocation Failure) 66M->7M(1015M) 22.821ms
Pluralsight Skills - Labs - Pluralsight
Author
Pluralsight Skills

Pluralsight Skills gives leaders confidence they have the skills needed to execute technology strategy. Technology teams can benchmark expertise across roles, speed up release cycles and build reliable, secure products. By leveraging our expert content, skill assessments and one-of-a-kind analytics, keep up with the pace of change, put the right people on the right projects and boost productivity. It's the most effective path to developing tech skills at scale.

What's a lab?

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.

Provided environment for hands-on practice

We will provide the credentials and environment necessary for you to practice right within your browser.

Guided walkthrough

Follow along with the author’s guided walkthrough and build something new in your provided environment!

Did you know?

On average, you retain 75% more of your learning if you get time for practice.
Ready to get started?
View individual plans View team plans