如何在 Linux (Centos 7) shell 上在后台正确运行 Spring Boot Batch 应用程序？

Question

I have to run a Java Spring Boot application on a Linux machine (Centos 7). I am connecting to a shell via SSH. This application is in jar format and implement a batch application and containins itself its scheduler.

I have to run it in background on a remote server in order that after that I quit the shell it is still run.

I have performed this command in order to run my application in background:

java -Xms256m -Xmx1024m -jar UpdateInfoBatch-0.0.1-SNAPSHOT.jar &

then I clicked on CTRL+C on my keyboard in order to obtain again the keyboard prompt on my shell.

and here the first trange behavior: I obtain again the shell prompt and the possibility to insert command but if the application log something it is appearing on the shell. Why? I expected that my application still run in background.

Anyway I now prompt this command in the my shell in order to check if my application is running:

xxx@xxx.yyy.it [~/zzz-import-data-batch]# ps aux | grep java xxx 23307 15.3 1.6 4871172 418980 pts/0 Sl 10:23 0:22 java -Xms256m -Xmx1024m -jar UpdateInfoBatch-0.0.1-SNAPSHOT.jar webadmin 23522 0.0 0.0 112812 980 pts/0 S+ 10:25 0:00 grep --color=auto java

And yes my application seems to correctly run (the first one).

Then I close the connection to my shell, I log into it again and I perform again the previous command but now I obtain this:

xxx@xxx.spaccount.it [~/zzz-import-data-batch]# ps aux | grep java xxx 23919 0.0 0.0 112812 980 pts/0 S+ 10:27 0:00 grep --color=auto java

As you can see after that I disconnect from the shell, when I do a new login my batch application seems that it is not running (and infact my job application doesn't runned).

What is wrong? What am I missing? What could be a good way to run in background my java jar batch application?

Answer 1

Generally you will want to redirect output, and you can use the nohup command to spawn it to the background. If you don't care about capturing stdout or stderr, you can direct those to /dev/null

nohup java -Xms256m -Xmx1024m -jar UpdateInfoBatch-0.0.1-SNAPSHOT.jar >/dev/null 2>&1 &