如何在 AWS EC2 上自动启动 2 个 Java jar？

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Command to start 2 Java JARs in the same time

I'm learning to deploy Spring Boot apps on AWS EC2. And I know how to automate app launch, when I start the EC2 instance, I don't need to manually use the command java -jar java-service.jar, I just add this command in the /etc/rc.local file and that is all. But I have 2 microservice, and I want to start both of them automatically, but if I try to add both commands in the /etc/rc.local it's not working, only the first service will start, the second service will not start. So I have the commands added like this:

And after I start the EC2 instance only the first service is started:

Thank you!

Answer 1

I recommend to use Systemd. Create a Systemd unit file for every microservice, save it in /etc/systemd/system/my-app.service . Something like that:

[Unit]
Description=My Java app
After=syslog.target network.target

[Service]
EnvironmentFile=/etc/sysconfig/my-app-env
WorkingDirectory=/my/app/home
ExecStart=/usr/bin/java $JAVA_OPTS -jar my-app.jar
KillMode=process
User=my-app-user
Restart=on-failure

[Install]
WantedBy=multi-user.target

Then, run:

systemctl daemon-reload
systemctl enable --now my-app

After that, you can use:

systemctl status my-app
systemctl stop my-app
systemctl start my-app

Answer 2

I am not a unix expert, but I see the only issue in running 2 java commands from terminal is that unless the first command returns, the next command is not executed. So, I think the solution would be run the 1st command in some interactive mode so that the other commands can be executed simultaneously.

There are ways in unix shell to run a command in background. I found this useful link - https://www.maketecheasier.com/run-bash-commands-background-linux/

In bash terminal, a command can be made to run in background by appending it with & . So, I think you should be able to start both jars if you do something like -

java -jar /home/ec2-user/first.jar &
java -jar /home/ec2-user/second.jar

Answer 3

I am not sure which system you are using in starting application: For linux base system, you can use crontab to schedule the task when the server reboot. Follow this steps:

1. Download crontab

   #apt-get install cron

2. Edit the file file to enable the task

   crontab -e

   (Choose Vim or nano to edit the task)

3. Add this code to your server

   @reboot /usr/bin/java -jar XXXXX.jar

4. Save your file

5. Check the result

   crontab -l #systemctl status cron

This method works in my Debian system. For more details, you can refer to How to automatically run program on Linux startup

Answer 4

Another solution is to bundle your jars into Docker images. This of course requires Docker runtime and adds an overhead, but it also has some benefits:

• Complete separation of jar files. Easily use different java versions.
• No need to worry about differences of local and ec2 environment.
• Easily scale to 3 or more jars.
• Use Docker Cli to build and start containers. Works great in a Devops Pipeline.

You can read here to learn how to create Spring Boot Docker images. After you build an image. You start it like this.:

docker run -p 8080:8080 springio/gs-spring-boot-docker

You can run as many docker run commands you need, one after another.

Answer 5

If you are running from bash, then command separator is semicolon ";" so you need to quote the value.

java -jar "/home/ec2-user/first.jar;/home/ec2-user/second.jar"

Answer 6

coupon service

1. Run the command 'java -jar /home/ec2-user/coupon-service-0.0.1-SNAPSHOT.JAR'
2. Press CTRL+Z, type bg, press Enter, type disown, press Enter.

product service

1. Run the command 'java -jar /home/ec2-user/product-service-0.0.1-SNAPSHOT.JAR'
2. Press CTRL+Z, type bg, press Enter, type disown, press Enter.

NOTE : Both services should have different ports.