Why are zombie ssh connections listed in Red Hat Ceph Storage 5.x?

Issue

• In Red Hat Ceph Storage ( RHCS ) nodes running mgr services, there might be zombie ( defunct ) ssh connections listed in the output of a ps command. For instance:

  [root@osds-2 ceph]# ps -ef | grep defunct
  
  ceph     1302109 1301643  0 Jun14 ?        00:00:00 [ssh] <defunct>
  ceph     1302110 1301643  0 Jun14 ?        00:00:00 [ssh] <defunct>
  ceph     1302111 1301643  0 Jun14 ?        00:00:00 [ssh] <defunct>
  ceph     1302112 1301643  0 Jun14 ?        00:00:00 [ssh] <defunct>
  ceph     1302113 1301643  0 Jun14 ?        00:00:00 [ssh] <defunct>
  

• For additional information about what a zombie process is, please take a look at KCS article 1501 - What is a zombie (defunct) process?

• Why are these processes showing up? Is there any way to get rid of them?