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Nagios 4.3.4 and mod-gearman

Posted: Mon Oct 09, 2017 6:14 am
by Pitone_Maledetto
Hi all,
I am writing this because I have tried everything to make Nagios and mod-gearman working but to not avail.
I have installed it several times using the provided .deb files (https://labs.consol.de/repo/stable/debi ... ary-amd64/), I have installed using the apt sources from Debian 9 repositories and finally I have compiled it from source even using the Nagios 4 lib and headers files to make it work.

Now after a couple of successful checks:

Code: Select all

<+++
[2017-10-09 11:40:57][3252][TRACE] 243 --->
type=host
result_queue=check_results
host_name=localhost
start_time=1507545657.0
next_check=1507545657.0
timeout=30
core_time=1507545657.952754
command_line=/usr/local/nagios/libexec/check_ping -H 127.0.0.1 -w 3000.0,80% -c 5000.0,100% -p 5
host_name=localhost
core_start_time=1507545657.0
start_time=1507545657.953982
finish_time=1507545662.40688
return_code=0
exited_ok=1
source=Mod-Gearman Worker @ debian9
output=PING OK - Packet loss = 0%, RTA = 0.07 ms|rta=0.071000ms;3000.000000;5000.000000;0.000000 pl=0%;80;100;0\n

[2017-10-09 11:41:02][3252][TRACE] add_job_to_queue(check_results, (null), 2, 1, 1, 1)
[2017-10-09 11:41:02][3252][TRACE] 287 --->host_name=localhost
core_start_time=1507545657.0
start_time=1507545657.953982
finish_time=1507545662.40688
return_code=0
exited_ok=1
source=Mod-Gearman Worker @ debian9
output=PING OK - Packet loss = 0%, RTA = 0.07 ms|rta=0.071000ms;3000.000000;5000.000000;0.000000 pl=0%;80;100;0\n
Nagios crashes:

Code: Select all

[1507546052] mod_gearman: initialized version 3.0.5 (libgearman 0.33)
[1507546052] Event broker module '/usr/local/lib/mod_gearman/mod_gearman_nagios4.o' initialized successfully.
[1507546052] Successfully launched command file worker with pid 3622
[1507546127] Caught SIGSEGV, shutting down...
In another installation Nagios crashed only when I forced a check via the web console which it makes the set-up useless anyway.
Now if someone has successfully managed to install mod-gearman on Nagios Core 4 using Debian 9 and would like to share the knowledge it would be very appreciated because I can't make it work. I had some pointers from the developers but not really enough to make it work maybe they are not bothered since they decided not to support Nagios.
If not could someone advise me on an alternative for mod-gearman?
Thank you very much in advance.

Re: Nagios 4.3.4 and mod-gearman

Posted: Mon Oct 09, 2017 4:54 pm
by cdienger
It sounds like there may have been a problem compiling or the conflicts with old installs of gearman. How did you run the configure command? Speaking from experience with a recent case, I would suggest compiling on as clean of a system as possible to avoid any conflicts with or references to old installs.

Re: Nagios 4.3.4 and mod-gearman

Posted: Tue Oct 10, 2017 2:51 am
by danjoh
You probably need to compile mod_gearman yourself to match your installation of Nagios.

See my posts in this thread: https://support.nagios.com/forum/viewto ... =7&t=45491
and: https://github.com/sni/mod_gearman/issues/122

Re: Nagios 4.3.4 and mod-gearman

Posted: Tue Oct 10, 2017 3:06 am
by Pitone_Maledetto
Hi cdienger,
I am working with VMWare.
I have a couple of VMs with snapshots of clean Debian 9 with a working instance of Nagios Core 4.3.4 to which I am reverting to whenever I need to re-install mod-gearman again.
So I think my environment might have nothing to do with it. As of now my opinion of mod-gearman is the one of a flaky system also because I have read many people having several problems with it.
It seems very unstable for a production implementation.
This is only my opinion I am waiting and willing to be proven wrong.
I will however re-install for the last time the all lot using the old version of gearmand (Job Server) which is also listed on the repository linked above since I have been using the apt available one (I don't think this has anything to do with the problem).
I am also interested in alternatives if any.
Thank you.

Re: Nagios 4.3.4 and mod-gearman

Posted: Tue Oct 10, 2017 3:18 am
by Pitone_Maledetto
Hi danjoh,
in my first post when I said that I have compiled mod-gearman using the lib and headers files of Nagios 4 I was indeed following your instructions :)
I have read and tried more or less everything before venting here for help.
I will try again.
Do you have yours working fine? Is it on Debian 9?
Thanks

Re: Nagios 4.3.4 and mod-gearman

Posted: Tue Oct 10, 2017 3:46 am
by danjoh
No, we are not using Debian, we are running on RHEL 7.4, with the flowing "components":
  • Nagios 4.3.4 (compiled from source)
    mod_gearman 3.0.5 (compiled from source, with "patched" header-files from Nagios-4.3.4)
    gearmand 0.33 (from labs.consol.de)

Re: Nagios 4.3.4 and mod-gearman

Posted: Tue Oct 10, 2017 12:19 pm
by cdienger
Are you using gearman to divide work amongst different machines? An alternative would be to use a distributed model to divide the work between multiple core machines and then have them forward their check results to a central core server using NRDP. Below are some links to documentation if you want to explore this option more:

https://support.nagios.com/kb/article/n ... ource.html
https://assets.nagios.com/downloads/nrd ... erview.pdf
https://assets.nagios.com/downloads/nag ... ios-XI.pdf

Re: Nagios 4.3.4 and mod-gearman

Posted: Wed Oct 11, 2017 1:34 am
by danjoh
That was what we were doing before,with Nagios 3.x. We decided to move to a gearman approach when we upgraded to 4.x.
The main reason for moving away from multiple Nagios cores to just one was the overhead when managing multiply cores (config changes has to be done on at least two hosts as opposed to just one) and with the "multi-core" you can not (to my knowledge) trigger a forced check from the GUI on a "remote" core.
We are awaiting the previously announced "remote worker" in Nagios Core (it is not on the roadmap any more :cry: ).

Re: Nagios 4.3.4 and mod-gearman

Posted: Wed Oct 11, 2017 3:23 am
by Pitone_Maledetto
It would be great for Nagios to explore an in house "mod-gearman" solution for load distribution and scalable architecture.

Re: Nagios 4.3.4 and mod-gearman

Posted: Wed Oct 11, 2017 4:01 am
by danjoh
+1 for that!