How-To: Check for Listener/ Notifier Service Status

listener
notifier
ucs-4
howto

#1

Howto Check for Listener/ Notifier Service Status

This article will describe how to check if an issue with listener or notifier service on UCS hosts exist.

Step 1

Get state of replication:

/usr/lib/nagios/plugins/check_univention_replication

Hint: This is a monitoring plugin that can (and should) be used with most monitoring solutions. The Nagios Server App from the Univention App Center will use this plugin automatically for all UCS systems joined to the domain.

Result 1

CRITICAL: no change of listener transaction id for last 0 checks (nid=3030 lid=3018)
Repeat the check a couple of seconds later. If it still shows “CRITICAL” proceed to step 2.

Result 2

CRITICAL: failed.ldif exists
Follow troubleshooting guideline in this article.

Result 3

OK: replication complete (nid=3122 lid=3122)
The listener state on this host is fine. Repeat the steps for all hosts in your domain.

Step 2

Your replication seems to be stuck. Restart both services (please keep in mind that univention-directory-notifier only exists on UCS systems with the role Master and Backup):

root@master:~# systemctl start univention-directory-listener
root@master:~# systemctl start univention-directory-notifier

Verify services are running fine:

root@master:~# sv status univention-directory-notifier | sed -n 's/:.*//p'
root@master:~# sv status univention-directory-listener | sed -n 's/:.*//p'

Result 1

run
Service is running.

Result 2

down
Service has been shut down intentionally. Restart the service as shown above. If it still shows down or finished proceed with next step.

Result 3

finished
Service ended due to an error. Proceed with next step.

Step 3

Increase debug level and restart for both services.

root@master:~# ucr set listener/debug/level=4 # default: 2
root@master:~# ucr set notifier/debug/level=4 # default:2
root@master:~# systemctl start univention-directory-listener
root@master:~# systemctl start univention-directory-notifier

You might see more informative messages in the log files. See checks in the next steps.

Step 4

Notifier

Note: You should check notifier on all master and backup servers

Check logfile for details about the error.
The Notifier start is shown in the logfile with the line containing DEBUG_INIT.
In the following you see expected debug messages when everything is fine.
If it shows ERROR you should do further troubleshooting.

root@master:~# tail -f /var/log/univention/notifier.log
11.04.19 09:02:06.194  DEBUG_INIT
11.04.19 09:02:06.194  TRANSFILE   ( ALL     ) : LOCK from notify_transaction_get_last_notify_id
11.04.19 09:02:06.194  TRANSFILE   ( ALL     ) : LOCK /var/lib/univention-ldap/notify/transaction
11.04.19 09:02:06.194  TRANSFILE   ( ALL     ) : FCLOSE start
11.04.19 09:02:06.194  TRANSFILE   ( ALL     ) : FCLOSE end
11.04.19 09:02:06.194  TRANSFILE   ( ALL     ) : UNLOCK /var/lib/univention-ldap/notify/transaction
11.04.19 09:02:06.195  TRANSFILE   ( INFO    ) : Last transaction id = 3122

Listener

Note: You should check listener on all servers

Check logfile for details about the error.
The Listener start is shown in the logfile with the line containing DEBUG_INIT.
In the following you see expected debug messages when everything is fine.
If it shows ERROR you should do further troubleshooting.

root@master:~# tail -f /var/log/univention/listener.log
11.04.19 09:01:45.876  DEBUG_INIT
11.04.19 09:01:45.886  LISTENER    ( WARN    ) : Notifier/LDAP server is master.multi.ucs:7389
11.04.19 09:01:45.886  LDAP        ( PROCESS ) : connecting to ldap://master.multi.ucs:7389
11.04.19 09:01:45.893  LDAP        ( INFO    ) : simple_bind as cn=admin,dc=multi,dc=ucs
11.04.19 09:01:45.893  LISTENER    ( INFO    ) : connecting to notifier master.multi.ucs:6669
11.04.19 09:01:45.894  LISTENER    ( INFO    ) : established connection to 10.250.200.100 port 6669
11.04.19 09:01:45.894  LISTENER    ( ALL     ) : >>>Version: 3

Still failing

If either Notifier or Listener still do not start properly you might need to open a support ticket or use community support.
To check if the notifier/ listener files are corrupted, use this article.


Troubleshooting: Listener-/Notifier
Upgrade to UCS 4.4 failing join script for Radius and Appcenter
Broken Replication
Accessing Samba Shares
[SOLVED] Problem with UDN Replication (Error retrieving notifier ID from the UDN)
Problem: Notifier.log Shows Traceback
[SOLVED] Problem with UDN Replication (Error retrieving notifier ID from the UDN)