SoFunction
Updated on 2025-04-07

How to implement Tomcat automatic restart and daily scheduled startup

introduction

In web application development, Tomcat is a lightweight web server and is widely used in the deployment of Java Web applications. However, during actual operation, Tomcat may accidentally crash due to various reasons (such as memory overflow, insufficient system resources, etc.). In order to ensure high availability and stability of the service, it is very necessary to achieve automatic restart of Tomcat's downtime and regular start-up daily. This article will explain how to achieve this with simple script configuration.

1. Automatic restart after downtime

1.1 Manage Tomcat with systemd

For Linux systems, systemd can be used to manage Tomcat services, thereby achieving automatic restart. First, create a systemd service file:

sudo nano /etc/systemd/system/

Add the following to the open file:

[Unit]
Description=Apache Tomcat Web Application Container
After= 
 
[Service]
Type=forking
Environment=JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
Environment=CATALINA_PID=/opt/tomcat/temp/
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat
ExecStart=/opt/tomcat/bin/
ExecStop=/opt/tomcat/bin/
User=tomcat
Group=tomcat
RestartSec=10
Restart=always
 
[Install]
WantedBy=
  • ​​Environment​Lines define the environment variables required by Tomcat.
  • ​​ExecStart​and​ExecStop​Specifies the script path to start and stop Tomcat.
  • ​​RestartSec​​Defines the waiting time (seconds) before restart.
  • ​​Restart=always​​ means that no matter the exit status, it is always attempted to restart the service.

After saving and closing the file, reload​systemd​​To make the new service effective:

sudo systemctl daemon-reload

Start the Tomcat service and set the power-on self-start:

sudo systemctl start tomcat
sudo systemctl enable tomcat

1.2 Verify the automatic restart function

You can verify that the automatic restart is valid by manually stopping the Tomcat service:

sudo systemctl stop tomcat

After waiting for a few seconds, check if Tomcat has automatically restarted:

sudo systemctl status tomcat

If you see a status information like "active (running)", it means that the automatic restart function is working normally.

2. Start Tomcat regularly every day

2.1 Using Cron Job

​​​cron is a timed task scheduling tool in Linux systems that can be used to perform periodic tasks. To set up a daily schedule to start Tomcat, you can do it by editing the user's crontab file:

crontab -e

Add a line to the open file, such as starting Tomcat at 2 a.m. every day:

0 2 * * * /opt/tomcat/bin/

This line of command means to execute the specified script at 2:00 AM every day.

2.2 Notes

  • Make sure Tomcat's startup script path is correct.
  • If you need to start Tomcat under certain conditions (for example, only if Tomcat is not running), you can add the corresponding check logic to the script.

Through the above method, we can effectively realize Tomcat's automatic downtime restart and daily scheduled start, which is crucial to ensuring the stability and availability of web applications. Hope this article helps you!

Below I will provide example code for two scenarios: one is to automatically restart when Tomcat goes down, and the other is to start Tomcat regularly every day.

Scene 1: Tomcat automatically restarts when it crashes

We can use a simple shell script to monitor the Tomcat process and automatically restart it when it detects that the Tomcat process does not exist. Assume Tomcat is installed on​/opt/tomcat​​In the directory.

1. Create a monitoring script monitor_tomcat.sh

#!/bin/bash
 
TOMCAT_HOME=/opt/tomcat
PID=$(pgrep -f "catalina")
 
if [ -z "$PID" ]; then
    echo "Tomcat is not running. Restarting..."
    $TOMCAT_HOME/bin/
else
    echo "Tomcat is running with PID: $PID"
fi

2. Set the script to be executable

chmod +x /path/to/monitor_tomcat.sh

3. Run monitoring scripts once a minute using Cron timed tasks

Edit Cron Task:

crontab -e

Add the following line:

* * * * * /path/to/monitor_tomcat.sh

This way, it will check whether Tomcat is running once a minute, and will automatically restart if it is not running.

Scenario 2: Start Tomcat regularly every day

We can also use Cron to start Tomcat regularly every day. Suppose Tomcat is installed in the /opt/tomcat directory.

1. Create the startup script start_tomcat.sh

#!/bin/bash
 
TOMCAT_HOME=/opt/tomcat
$TOMCAT_HOME/bin/

2. Set the script to be executable

chmod +x /path/to/start_tomcat.sh

3. Start Tomcat every day at 6 am using the Cron timed task

Edit Cron Task:

crontab -e

Add the following line:

0 6 * * * /path/to/start_tomcat.sh

In this way, Tomcat will be started every morning at 6 o'clock.

  • Automatic restart of downtime: Check whether the Tomcat process exists by running the monitoring script once a minute, and start Tomcat if it does not exist.
  • Start regularly every day: Start Tomcat at a specified time (for example, every day at 6 am) through the Cron timing task.

When deploying web applications, it is very important to ensure high availability and stability of your application. As a commonly used Java application server, Tomcat may encounter various unexpected situations in actual use, resulting in service interruption. In order to improve the robustness of the system, you can write scripts to automatically restart the downtime and start Tomcat regularly every day.

Automatic restart of downtime

Automatic restart of downtime can be achieved by writing a simple shell script. This script periodically checks whether the Tomcat process exists, and restarts Tomcat if it does not exist.

Script example: restart_tomcat.sh

#!/bin/bash
 
# Tomcat installation pathTOMCAT_HOME=/opt/tomcat
 
# Check whether the Tomcat process existsif ! pgrep -f "" > /dev/null; then
    echo "Tomcat is not running. Attempting to restart..."
    # Start Tomcat    $TOMCAT_HOME/bin/
else
    echo "Tomcat is already running."
fi

Set up timing tasks

To enable this script to run regularly, it can be added to crontab. Edit the crontab file:

crontab -e

Add the following line to indicate whether Tomcat is running every 5 minutes:

*/5 * * * * /path/to/restart_tomcat.sh >> /var/log/restart_tomcat.log 2>&1

Start Tomcat regularly every day

If you need to start Tomcat regularly every day, you can also use crontab to achieve it. Suppose we want to start Tomcat at 1 a.m. every day.

Script example: daily_start_tomcat.sh

#!/bin/bash
 
# Tomcat installation pathTOMCAT_HOME=/opt/tomcat
 
# Stop Tomcat (if running)$TOMCAT_HOME/bin/
 
# Wait for a few seconds to make sure Tomcat stops completelysleep 10
 
# Start Tomcat$TOMCAT_HOME/bin/

Set up timing tasks

Edit the crontab file:

crontab -e

Add the following line to indicate that Tomcat is started at 1 a.m. every day:

0 1 * * * /path/to/daily_start_tomcat.sh >> /var/log/daily_start_tomcat.log 2>&1

Things to note

  1. Permissions issues: Make sure the script has executable permissions and can be used​chmod +x script_name.sh​​ Command.
  2. Logging: It is recommended to redirect the output of the script to the log file to facilitate subsequent troubleshooting.
  3. Environment variables: If Tomcat depends on certain environment variables, make sure these variables are set correctly in the script.
  4. Resource usage: Frequent restart operations may put pressure on system resources, and the inspection interval time is reasonably set.

Through the above methods, the stability and availability of Tomcat services can be effectively improved.

The above is the detailed content of the implementation method of Tomcat automatic restart and daily scheduled startup. For more information about Tomcat automatic restart and scheduled startup, please pay attention to my other related articles!