Unable to run nohup command from jenkins as a background process

Question

UPDATE: Based on below discussion I have edited my answer for more accurate description.

I am trying to run a nohup command from jenkins. The full command is

nohup java -jar /home/.../jar/server-process-0.35.jar prod >> /var/../server-process-prod.log 2>&1 &

This command does not work. I can see status as success in jenkins but no java process in linux. When I do 'ps -ef | grep java'

However when I remove the last '&', that is I change it from run in forground instead of background

It starts working. I can see the java process started.

The original command works fine If I run it on linux console.

I need to run it from jenkins in the original form that is as a backgorund process. So that it is independant of jenkins.

Any clues why is this happening?

Answer 1

In your jenkins shell script try:

  export BUILD_ID=dontKillMe
  nohup java -jar your_java_app.jar &

It worked for me!

Answer 2

Long story short, Jenkins kills all processes spawned by a job once that job finishes. To override this behavior, you need to set an environment variable.

The variable appears to vary from job type to job type. It used to be BUILD_ID , but for Pipeline jobs it is JENKINS_NODE_COOKIE , and there are several others mentioned in this answer .

So if you're running your command in Pipeline, it would look like this:

sh 'JENKINS_NODE_COOKIE=dontKillMe nohup java -jar /home/.../jar/server-process-0.35.jar prod >> /var/../server-process-prod.log 2>&1 &'

See the wiki on ProcessTreeKiller and this comment in the Jenkins Jira for more information.

Answer 3

I tried every possible combination with BUILD_ID but it didn't work. I made it though by putting "nohup command > output.txt&" inside a shell script ran by the execute shell in jenkins, it worked perfectly!

Answer 4

Got the same problem, added:

BUILD_ID=dontKillMe python /var/lib/jenkins/release.py

into Execute Shell -> Command and inside release.py there is:

os.system('nohup java -jar ' + new_jars_on_server + '/' + generated_jar_by_mvn_name + '&')

and it works

Answer 5

Best simple solution is to use "at now" instead of "nohup"

In your job jenkins (execute shell) put :

set +e #so "at now" will run even if java -jar fails
#Run java app in background
echo "java -jar $(ls | grep *.jar | head -n 1)" | at now + 1 min

Answer 6

what worked for me was wrapping the nohup java -jar ... command into sh file inside execute shell command, and running that same sh file right after:

echo "starting java jar..."
cd [some location where jar is]
echo "nohup java -jar [jar_name].jar &" > start-jar-in-background.sh
sh start-jar-in-background.sh
echo "started java jar"

If I had nohup java -jar ... inline with Execute shell command, then it didn't start it from some reasons. I spent quite some time on this, hope it helps to someone ';)

Answer 7

Simplest way :

`nohup java -jar [jar_name].jar >log_file_you_want 2>another_file`&

Answer 8

Hi ALL,
    set +e #so "at now" will run even if java -jar fails
 #Run java app in background
 echo "java -jar $(ls | grep *.jar | head -n 1)" | at now + 1 min
  above command worked for him, thanks @walid, & remove at the end (+ 1 min)