Running a background process in Pipeline job
Any one facing the same problem and using pipeline project, set JENKINS_NODE_COOKIE instead of BUILD_ID.

Dont waste your time setting HUDSON_COOKIE, HUDSON_SERVER_COOKIE, JENKINS_COOKIE or JENKINS_SERVER_COOKIE. None of them work for pipeline project.

Refer to https://issues.jenkins-ci.org/browse/JENKINS-28182 for more details.