[Xymon] How to setup a back-up xymon server

[Root, Paul T]

So, here at work, I have a main proxy server, and 2 backup/proxy machines on a fairly isolated network.

The proxies run on port 1984, and then a full server works on port 1985. The clients on that network only report to the backup/proxy servers.
By default the second backup (or tertiary server) doesn't send anything to the primary. We switch tasks.cfg as needed to for it to send.

The clients just send to the proxy servers, that solves the multi-source report problem.

As you say, you don't want the server (gui) to run on the raspberrypi. So there are 2 things you can do for it.

1) make it a proxy not a server, and then have it report only to itself. Then configure the proxy portion to send to your main server.
2) Don't use the server software at all on the rpi, just use the client and turn on msgcache. Then have the client send to itself (127.0.0.1). This will save the data locally, and not even try to send to the xymon server.
        - Then in the xymon server's hosts.cfg file you add in comments pulldata=192.168.178.71 for the rpi. That way when it reaches the machine, it downloads the data.
        - Actually, I have issues, with some of those machines, that I have to do that for. And I have a lot of gaps in the graphs. So the proxy is probably better.

Paul.

-----Original Message-----
From: Xymon [mailto:xymon-bounces at xymon.com] On Behalf Of Wim Nelis
Sent: Wednesday, February 14, 2018 11:01 AM
To: xymon at xymon.com
Subject: [Xymon] How to setup a back-up xymon server

Xymon is also used to monitor my home-network. One of the clients is a raspberry
pi 0 (rpi0, IP address 192.168.178.71), which controls the home ventilation unit
and which will monitor more in the near future as sensors are added. Sometimes
the Wifi-connection is not operational for some time. The obvious results are
that status messages do not reach the xymon server (IP address 192.168.178.72),
and that the associated graphs (RRD's) are not updated.

I would like to be able to check the graphs once the network connection is
operational again. The current solution is to install a (secondary) xymon server,
version 4.3.28, on rpi0 as well. (Note that there is no intention to use this
xymon server for other purposes: there is no web server active on the rpi0, nor
would I like to have a web server on this tiny computer.) The configuration file
/etc/default/xymon-client on rpi0, which is included in file
/usr/lib/xymon/client/etc/xymonclient.cfg, is modified to contain the addresses
of both xymon servers:

XYMONSERVERS="127.0.0.1 192.168.178.72"

The default section and the host section for rpi0 in configuration file
/usr/lib/xymon/server/etc/analysis.cfg is the same on both xymon servers. The
client data arrives at the primary xymon server, resulting in tests and their
associated graphs. When the need arise, the RRD files are copied from rpi0 to the
primary xymon server, and can then be inspected. However, it seems that the data
arrives twice at the primary xymon server. Xymond reports:

Multi-source statuses
   rpi0:conn                 reported by 192.168.178.71 and 127.0.0.1
   rpi0:cpu                  reported by 192.168.178.71 and 127.0.0.1
   rpi0:disk                 reported by 192.168.178.71 and 127.0.0.1
   rpi0:files                reported by 192.168.178.71 and 127.0.0.1
   rpi0:inode                reported by 192.168.178.71 and 127.0.0.1
   rpi0:memory               reported by 192.168.178.71 and 127.0.0.1
   rpi0:msgs                 reported by 192.168.178.71 and 127.0.0.1
   rpi0:ports                reported by 192.168.178.71 and 127.0.0.1
   rpi0:procs                reported by 192.168.178.71 and 127.0.0.1

The associated graphs one the primary xymon server are not complete: quite often
de measurements of 2 or 3 consecutive periods of 5 minutes are missing. The xymon
logfile rrd-status.log shows that multiple RRD updates, with slightly different
values at about the same time, are the root cause of the incomplete graphs.

In this situation I would like to stop the secondary xymon server from sending
the test results to the primary xymon server. How can one achieve that?

Regards,

   Wim Nelis.

_______________________________________________
Xymon mailing list
Xymon at xymon.com
http://lists.xymon.com/mailman/listinfo/xymon
This communication is the property of CenturyLink and may contain confidential or privileged information. Unauthorized use of this communication is strictly prohibited and may be unlawful. If you have received this communication in error, please immediately notify the sender by reply e-mail and destroy all copies of the communication and any attachments.