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Troubleshooting the Zabbix Server

  • Make sure the Database of the Zabbix Server is up and running:
    # systemctl status mariadb
    # ps -ef | grep mariadbd
    # journalctl -xeu mariadb

    Otherwise the Zabbix Web Application will complain and the Zabbix Server will not start.
  • Make sure the Zabbix Server is up and running:
    # systemctl status zabbix-server
    # journalctl -xeu zabbix-server

  • Check the Zabbix Server Log for problems or reasons:
    # tail -n 100 /var/log/zabbix/zabbix_server.log

  • Check if Zabbix Server can connect to its Database. If not, this should be visible in the Zabbix Server Log. In the database you should see some Zabbix Processes connected:

Troubleshooting the Zabbix Web Interface

  • Check if a Webserver (for example Apache) is running so the Zabbix Web Interface can be executed:
    # systemctl status apache2
    # journalctl -xeu apache2

If everything is fine it should look as follows (Zabbix Server is running):


Troubleshooting the Zabbix Agent

  • Make sure the Zabbix Agent is running (check the Zabbix Agent Log).
  • Check if the Status of the Host is Monitored and if Availability is green.
  • If Availability is red and you see the following message:
    Got empty string from []. Assuming that agent dropped connection because of access permissions

    Check if the hostname of the Zabbix Agent matches with the name on the Host in the Zabbix Server (case sensitive, white space etc. matters!).
  • Set DebugLevel = 4 in the Zabbix Agent configuration file, restart the agent and see if you can see any reason in the agent log file (do not forget to set it back afterwards because it becomes very verbose).
  • Try to send a message manually from as the Zabbix Agent to the Zabbix Server:
    # sudo -u zabbix zabbix_sender --zabbix-server= \
    --host=mysql_2_4_2 --key=FromDual.MySQLmysql.Questions \
    --value="123456789" --verbose
    Info from server: "Processed 1 Failed 0 Total 1 Seconds spent 0.000180"
    sent: 1; skipped: 0; total: 1

  • Check under: Monitoring → Latest data if the data have been arriving (timestamp).
  • Try to reach the Zabbix Agent from as the Zabbix Server:
    # sudo -u zabbix zabbix_get --host= --source-address= --key="FromDual.MySQL.check"
    # echo $?

    This typically means that host does not match.
    # sudo -u zabbix zabbix_get --host= --source-address= --key="FromDual.MySQL.check"

    This means that the item FromDual.MySQL.check is not known to the Zabbix Server. Then you have possibly forgotten to ad the fpmmm module template to the host you want to monitor.
  • If you run the process module you should make sure, that the user running the Zabbix Agent has access to the PID file. Ideally you run the Zabbix agent with the same user as the database process runs or you configure MariaDB/MySQL in the way that the PID file located on a location where also other processes have access to it.

Troubleshooting the FromDual Performance Monitor Agent

Our philosophy is, that the fpmmm Agent is running under the O/S user mysql. For the fpmmm Agent, this is necessary because otherwise we do not have access to the PID file of the mysqld.

If all those hints do not help or if you have some comments or feedback please let us know at our FromDual Performance Monitor Forum (we do NOT cover Zabbix problems).