OPMS defunct processes keep respawning

Products

• CA App Synthetic Monitor
• NIMSOFT CLOUD USER EXPERIENCE MONITOR
• DX Application Performance Management

Issue/Introduction

Following the installation of an OPMS on new server and have observed defunct processes keep respawning 

root      79978 245031  0 09:03 ?        00:00:00 [bash] <defunct>
root      79980 245031  0 09:03 ?        00:00:00 [bash] <defunct>
root      79982 245031  0 09:03 ?        00:00:00 [bash] <defunct>
root      79989 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      79991 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      79994 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      79999 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>

they appear to restart every minute

Cause

This is a known behaviour of the monit process which is used to manage the OPMS system. The defunct process are child processes of the monit process

 

root      79978 245031  0 09:03 ?        00:00:00 [bash] <defunct>
root      79980 245031  0 09:03 ?        00:00:00 [bash] <defunct>
root      79982 245031  0 09:03 ?        00:00:00 [bash] <defunct>
root      79989 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      79991 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      79994 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      79999 245031  0 09:03 ?        00:00:00 [rbtm.sh] <defunct>
root      80073  62960  0 09:03 pts/0    00:00:00 grep --color=auto 245031
root     245031      1  0 Aug24 ?        00:01:36 /usr/bin/monit -I

This is described in the following monit documentation

 

"The asynchronous nature of the program check allows for non-blocking behaviour in the current Monit design, but it comes with a side-effect: when the program has finished executing and is waiting for Monit to collect the result, it becomes a so-called "zombie" process. A zombie process does not consume any system resources (only the PID remains in use) and it is under Monit's control and the zombie process is removed from the system as soon as Monit collects the exit status. This means that every "check program" will be associated with either a running process or a temporary zombie. This unwanted zombie side-effect will be removed in a later release of Monit."

 

Environment

Release : 10.x

Component : NIMSOFT CLOUD USER EXPERIENCE MONITOR

Resolution

No action is required - unless the number of zombie (defunct) processes starts to increase