Agent-receiver: stopped after Update to CEE 2.2.0

2.0.0p23.cee over 2.1.0p28.cee to 2.2.0.cee
debian 11

hi at all, my agent-receiver: stopped after Update to CEE 2.2.0, what can I do?

via journalctl -u cmk-agent-ctl-daemon.service I see this error:
ERROR [cmk_agent_ctl] Failed to listen on TCP socket for incoming pull connections.

but here is everything ok.:
checkmk:~# systemctl status cmk-agent-ctl-daemon.service
● cmk-agent-ctl-daemon.service - Checkmk agent controller daemon
Loaded: loaded (/lib/systemd/system/cmk-agent-ctl-daemon.service; enabled; vendor preset: enabled)
Active: active (running) since Thu 2023-05-25 15:02:33 CEST; 3min 8s ago
Docs: Monitoring Linux - The new agent for Linux in detail
Main PID: 650 (cmk-agent-ctl)
Tasks: 4 (limit: 19153)
Memory: 5.6M
CPU: 1.118s
CGroup: /system.slice/cmk-agent-ctl-daemon.service
└─650 /usr/bin/cmk-agent-ctl daemon

Mai 25 15:02:33 checkmk systemd[1]: Started Checkmk agent controller daemon.
checkmk:~# systemctl | grep cmk
cmk-agent-ctl-daemon.service loaded active running Checkmk agent controller daemon

Kind regards,

The agent receiver runs on the cmk server.

Where do you exactly have an issue? E.g. do you get on omd status a stopped receiver or do you have issues with the agents?

Instead of an installed and running agent he isn’t listinig on port 6556?

And why is the agent receiver not running anymore, do you have an idea?

The agent is working now. I forgot, that i needed to register it.

But what about the stopped agent receiver? why is it stopped and for what do I need it?

On my CRE machine the agent-receiver is ok after the update prcess from 2.0.0 to 2.2?

Agent controller is running on the agent side and is handling the communication.
Agent receiver is running on the Checkmk server and handles the communication coming in from the agent + TLS registration.

The error shown in the log regarding cmk-agent-ctl ERROR … address in use you can ignore.
For the receiver, just to a
omd restart agent-receiver
and check if that fixes it or what error message is then shown.

he says “starting ok”, but…:

This error is shown in the log:
heckmk:~# tail -n 40 /opt/omd/sites/psgmon/var/log/agent-receiver/error.log
[2023-05-25 15:17:45 +0200] [946] [INFO] Worker exiting (pid: 946)
[2023-05-25 15:17:45 +0200] [942] [INFO] Shutting down: Master
[2023-05-25 15:17:45 +0200] [942] [INFO] Reason: Worker failed to boot.
[2023-05-25 18:34:16 +0200] [1418522] [INFO] Starting gunicorn 20.1.0
[2023-05-25 18:34:16 +0200] [1418522] [INFO] Listening at: http://[::]:8000 (1418522)
[2023-05-25 18:34:16 +0200] [1418522] [INFO] Using worker: agent_receiver.worker.ClientCertWorker
[2023-05-25 18:34:16 +0200] [1418529] [INFO] Booting worker with pid: 1418529
[2023-05-25 18:34:16 +0200] [1418529] [ERROR] Exception in worker process
Traceback (most recent call last):
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/”, line 589, in spawn_worker
File “/omd/sites/psgmon/lib/python3.11/site-packages/uvicorn/”, line 66, in init_process
super(UvicornWorker, self).init_process()
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/workers/”, line 134, in init_process
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/workers/”, line 146, in load_wsgi
self.wsgi =
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/app/”, line 67, in wsgi
self.callable = self.load()
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/app/”, line 58, in load
return self.load_wsgiapp()
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/app/”, line 48, in load_wsgiapp
return util.import_app(self.app_uri)
File “/omd/sites/psgmon/lib/python3.11/site-packages/gunicorn/”, line 359, in import_app
mod = importlib.import_module(module)
File “/omd/sites/psgmon/lib/python3.11/importlib/”, line 126, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File “”, line 1206, in _gcd_import
File “”, line 1178, in _find_and_load
File “”, line 1142, in _find_and_load_unlocked
ModuleNotFoundError: No module named ‘agent_receiver.apps’
[2023-05-25 18:34:16 +0200] [1418529] [INFO] Worker exiting (pid: 1418529)
[2023-05-25 18:34:17 +0200] [1418522] [INFO] Shutting down: Master
[2023-05-25 18:34:17 +0200] [1418522] [INFO] Reason: Worker failed to boot.

If you have a support contract, I’d recommend to create a ticket. Looks to me like something which can be much quicker fixed via support. And something which should be fixed.