Hi Chris!

As the Debian developer who released 4.3.30-2, I'll try to help here, but I'm not sure, whether I can help, since I didn't try this out on Ubuntu yet but only on Debian 12.

apt-cache policy xymon

xymon: Installed: 4.3.30-2build3

Okay, this should be 4.3.30-2 without changes but only re-build on Ubuntu.

I hope that you have xymon-client installed, too?

Xymon does start and generates the pages which I can view but is missing the client tests (disk, cpu, memory etc..), and the rrd graphs Confirm port 1984 is listening

Okay, just tried this myself on a freshly installed Debian 12 (with 4.3.30-2 backported to Debian 12). I first had to install apache2 first, otherwise enabling mod rewrite and xymon conf may have been done by hand. Then I installed xymon and xymon-client and used 127.0.0.1 as "Xymon server" via debconf (as well as the FQDN of the server as "Client hostname") on installation of xymon-client.

**** snip **** 2024-09-13 14:50:52.967847 Peer not up, flushing message queue *** buffer overflow detected ***: terminated 2024-09-13 14:50:53.187820 Child process 5496 died: Signal 6 2024-09-13 14:51:52.977025 Peer at 0.0.0.0:0 failed: Broken pipe **** snip ****

Hmmm, I doesn't observe these on Debian, maybe Ubuntu uses some other type of hardening, which breaks the package or there is some other build problem?

This is a fresh install and the only change I made in xymonserver.cfg are: XYMONSERVERIP="server ip"

Why do you do so? The idea of the configuration is that you define the Xymon server IP via debconf when installing xymon-client, which sets XYMONSERVERS="127.0.0.1" (or a different IP) in /etc/default/xymon-client This variable is used as the server IP automatically.

With this setup xymon comes up and I see the client tests and after some cycles also some data in the graphs. Works without problems for me.

Maybe I really have to try this out with Ubuntu 24.04...

[...]

Okay, I now have a minimal Ubuntu 24.04 server installed, installed apache2 and xymon (including xymon-client). Again I used 127.0.0.1 as the server IP (which is written to /etc/defaults/xymon-client). And now I can reproduce your issue. I see no local data fields (disk, cpu,...) and I see "buffer overflow detected" messages in the logs.

Comparing "systemctl status xymon" I see, that 2*xymond_rrd, xymond_client, xymond_alert are missing (AKA not running) on the Ubuntu server, seems that this are the processes that had a buffer overflow.

So I tried to re-compile 4.3.30-2 on this server, but the result didn't change (still does not work as expected).

Since you wrote, that 4.3.30-1build3 (from Ubuntu 23.10) worked without problems, I downloaded the source of 4.3.30-1 and did another build but this also doesn't work without problems.

So from my perspective there is some problem with the compile options or hardening in Ubuntu 24.04, which breaks the xymon package, while 4.3.30-1build3 used a different build system (Ubuntu 23.10), which wasn't that strict and didn't run into issues.

Maybe I should compare compiler options between Ubuntu 24.04 and Debian 12 (and/or Debian unstable) and try to reproduce the issue on Debian. Or I should try to find out, where the "buffer overflow detected" messages come from and fix the root cause. But that's a job for another day...

Sorry not to have a solution for you now, but this seems to be harder to fix...

Greetings Roland