Rotate Tomcat Localhost Log: Step-by-Step Guide

If you're running a Tomcat web server on your local machine, you may find that the localhost.log file grows very quickly, taking up valuable disk space. In order to avoid this problem, it's important to rotate the log file on a regular basis. Here's a step-by-step guide to rotating the localhost.log file in Tomcat.

Step 1: Stop Tomcat

The first thing you need to do is stop Tomcat so that it's not actively writing to the log file. You can do this by running the following command:

sudo systemctl stop tomcat

Step 2: Create a Backup of the Log File

Before you rotate the log file, it's a good idea to create a backup of the current file. This will ensure that you don't lose any important data. You can create a backup by running the following command:

sudo cp /var/log/tomcat9/localhost.log /var/log/tomcat9/localhost.log.bak

Step 3: Rotate the Log File

Now that you have a backup of the log file, you can rotate it using the logrotate command. First, create a new configuration file for logrotate by running the following command:

sudo nano /etc/logrotate.d/tomcat

Then, add the following lines to the file:

/var/log/tomcat9/localhost.log {
    copytruncate
    daily
    rotate 7
    compress
    missingok
}

This will rotate the log file daily, keeping a maximum of 7 rotated files. The copytruncate option ensures that the file is copied and then truncated, so that Tomcat can continue writing to the file without interruption.

Step 4: Start Tomcat

Finally, start Tomcat again by running the following command:

sudo systemctl start tomcat

And that's it! You've successfully rotated the localhost.log file in Tomcat. This will help keep your disk space usage under control and ensure that you don't lose any valuable log data.