We are trying to upgrade our Jenkins to the latest LTS 2.19.3 and currently doing some testing on it. We found that Jenkins hangs and fails to restart when a multijob is in progress using 32bit java that is used by this Jenkins.

Steps to reproduce:
1. Install this version of jenkins and create some multijobs
2. When the multijob is running, restart jenkins---- observation: Jenkins does not restart and job continues to build.
3. Now do a service restart--- this also does not happen
4. Try step 3 few times to see if it works.
5. Now kill the running java instance and restart the Jenkins service ---- brings back Jenkins

Can we use a 64bit java to solve this problem as the 32bit Java that comes with Jenkins cannot have a heap greater than 1.5GB or is it because of some other reason?