Good morning!

I have an advanced SSH Script Sensor in PRTG. It runs a script that has a chance to hang indefinitely. When it runs, I can see on the target server that the sshd process gets created as expected, and we have subprocesses for the script and the commands:

[user@server ~]# ps -ef | grep prtg
root     26698  1553 30 11:22 ?        00:00:00 sshd: prtgadm [priv]
prtgadm  26707 26698  0 11:22 ?        00:00:00 sshd: prtgadm@notty
prtgadm  26708 26707  0 11:22 ?        00:00:00 -bash
prtgadm  26719 26708  0 11:22 ?        00:00:00 /bin/bash /var/prtg/scriptsxml/disk_free.sh
prtgadm  26764 26719  0 11:22 ?        00:00:00 stat -f -c %b /user/prtg_test_monitor
[user@server ~]#

When the script hangs indefinitely, PRTG will try to kill it after the timeout (shell timeout is 10 seconds in my case). I've found that, while the sshd processes get killed correctly, the shell is not killed, but orphaned. The process and it's subprocesses linger: 

[user@server ~]# ps -ef | grep prtg
prtgadm  26708 1      0 11:22 ?        00:00:00 -bash
prtgadm  26719 26708  0 11:22 ?        00:00:00 /bin/bash /var/prtg/scriptsxml/disk_free.sh
prtgadm  26764 26719  0 11:22 ?        00:00:00 stat -f -c %b /user/prtg_test_monitor
[user@server ~]#

Is there a way to get PRTG to correctly kill it's sshd process and all subprocesses?

Article Comments

Attention: This article is a record of a conversation with the Paessler support team. The information in this conversation is not updated to preserve the historical record. As a result, some of the information or recommendations in this conversation might be out of date.

What kind of Linux is that if I may ask? Haven't seen this yet :)

PRTG Scheduler | PRTGapi | Feature Requests | WMI Issues | SNMP Issues

Kind regards,
Stephan Linke, Tech Support Team


Oct, 2018 - Permalink

We first observed the behavior on RHEL 6.10, and I recreated the issue above on Oracle Linux (a RHEL derivative) 7.5.


Oct, 2018 - Permalink