Have a single thruk-agent that looks to be stuck in an error state loop where it fails hook: update-status. This causes aggregate thruk to lose connection to this instance as it is, I'm assuming, stopping and starting the thruk-agent every 5 mins or so (when hook is triggered). Log is posted below. Output is filled with the same loop.
2019-07-31 17:12:02 DEBUG update-status Hit:1 http://ppa.launchpad.net/canonical-bootstack/thruk/ubuntu bionic InRelease
2019-07-31 17:12:02 DEBUG update-status Ign:2 https://artifacts.elastic.co/packages/5.x/apt stable InRelease
2019-07-31 17:12:02 DEBUG update-status Hit:3 https://artifacts.elastic.co/packages/5.x/apt stable Release
2019-07-31 17:12:02 DEBUG update-status Hit:4 http://archive.ubuntu.com/ubuntu bionic InRelease
2019-07-31 17:12:02 DEBUG update-status Hit:5 http://ppa.launchpad.net/landscape/19.01/ubuntu bionic InRelease
2019-07-31 17:12:02 DEBUG update-status Hit:6 http://archive.ubuntu.com/ubuntu bionic-updates InRelease
2019-07-31 17:12:02 DEBUG update-status Hit:7 http://archive.ubuntu.com/ubuntu bionic-security InRelease
2019-07-31 17:12:02 DEBUG update-status Hit:9 http://ppa.launchpad.net/telegraf-devs/ppa/ubuntu bionic InRelease
2019-07-31 17:12:02 DEBUG update-status Hit:10 http://archive.ubuntu.com/ubuntu bionic-backports InRelease
2019-07-31 17:12:06 DEBUG update-status Reading package lists...
2019-07-31 17:12:07 DEBUG juju-log PGP key found (looks like Radix64 format)
2019-07-31 17:12:07 DEBUG juju-log Importing PGP key from keyserver
2019-07-31 17:12:07 DEBUG update-status Warning: apt-key output should not be parsed (stdout is not a terminal)
2019-07-31 17:12:07 DEBUG update-status Executing: /tmp/apt-key-gpghome.kQWEMfW3Dz/gpg.1.sh --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 7A207542
2019-07-31 17:12:07 DEBUG update-status gpg: key 4B9A81747A207542: "Launchpad PPA for Canonical Bootstack" not changed
2019-07-31 17:12:07 DEBUG update-status gpg: Total number processed: 1
2019-07-31 17:12:07 DEBUG update-status gpg: unchanged: 1
2019-07-31 17:12:08 DEBUG update-status Ign:1 https://artifacts.elastic.co/packages/5.x/apt stable InRelease
2019-07-31 17:12:08 DEBUG update-status Hit:2 https://artifacts.elastic.co/packages/5.x/apt stable Release
2019-07-31 17:12:08 DEBUG update-status Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease
2019-07-31 17:12:08 DEBUG update-status Hit:5 http://ppa.launchpad.net/canonical-bootstack/thruk/ubuntu bionic InRelease
2019-07-31 17:12:08 DEBUG update-status Get:6 http://archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]
2019-07-31 17:12:08 DEBUG update-status Hit:7 http://ppa.launchpad.net/landscape/19.01/ubuntu bionic InRelease
2019-07-31 17:12:08 DEBUG update-status Hit:8 http://ppa.launchpad.net/telegraf-devs/ppa/ubuntu bionic InRelease
2019-07-31 17:12:08 DEBUG update-status Get:9 http://archive.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]
2019-07-31 17:12:09 DEBUG update-status Get:10 http://archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]
2019-07-31 17:12:09 DEBUG update-status Fetched 252 kB in 2s (162 kB/s)
2019-07-31 17:12:10 DEBUG update-status Reading package lists...
2019-07-31 17:12:10 INFO juju-log Installing ['thruk', 'pwgen', 'apache2-utils'] with options: ['--option=Dpkg::Options::=--force-confold']
2019-07-31 17:12:11 DEBUG update-status Reading package lists...
2019-07-31 17:12:11 DEBUG update-status Building dependency tree...
2019-07-31 17:12:11 DEBUG update-status Reading state information...
2019-07-31 17:12:11 DEBUG update-status pwgen is already the newest version (2.08-1).
2019-07-31 17:12:11 DEBUG update-status apache2-utils is already the newest version (2.4.29-1ubuntu4.8).
2019-07-31 17:12:11 DEBUG update-status thruk is already the newest version (2.24-2ubuntu6).
2019-07-31 17:12:11 DEBUG update-status 0 upgraded, 0 newly installed, 0 to remove and 91 not upgraded.
2019-07-31 17:12:11 DEBUG update-status active
2019-07-31 17:12:13 DEBUG juju-log Incomplete relation: NEMRelation
2019-07-31 17:12:13 DEBUG update-status inactive
2019-07-31 17:12:13 DEBUG juju-log Incomplete relation: NEMRelation
2019-07-31 17:12:43 INFO juju-log Writing file /etc/thruk/thruk_local.conf root:root 444
2019-07-31 17:12:43 INFO juju-log thruk-agent starting
As an addition. The problem is that every time update-status is called by juju (every 5 minutes) all kind of interaction with the repository is performed.
Due to bug LP#1311056 this will result in an additional commented out deb source file. Causing the update-status call to become slower and slower every time, and it will eventually bring the machine down and/or nagios will stop functioning for that cloud.
It seems most prominent on xenial deployments, but it feels as a waste of cpu cycles to check every 5 minutes of the sources files are okay, to run an 'apt update' and to make sure that the deb packages are installed. These should a 1 time install only imho.