Zabbix has two types of agent checks: Active and Passive. Each type has its own advantages and disadvantages, which we will examine in this article along with how to configure them.
Check types
Active Zabbix Agent Checks are initiated by the Zabbix Server. When monitoring a large number of machines or collecting data at specific intervals, active checks are useful. They are also useful when monitoring data that changes frequently, such as CPU usage or network traffic. Active checks can be scheduled to run at specific intervals, allowing administrators to collect data at regular intervals.
Passive Zabbix Agent Checks are initiated by the Zabbix Agent on the remote machine. When there is a change in the monitored data, the Zabbix Agent sends data to the Zabbix Server. This means that the Zabbix Server does not need to continuously poll the remote machines, reducing network traffic and server load. Passive checks are useful when monitoring data that changes infrequently, such as disk usage or memory usage. Passive checks can also be useful when monitoring machines that are behind firewalls or NATs, as the Zabbix Server does not need to initiate the checks.
Configuring checks
To configure the Zabbix Agent for Active or Passive checks, modify the /etc/zabbix/zabbix_agentd.conf configuration file. Set the "Server" option to the IP address or hostname of the Zabbix Server for Passive checks, and for Active checks, set the "ServerActive" option. Note that you can configure both active and passive modes at the same time.
In the Zabbix web interface, you can configure the type of check for an item. Go to "Configuration" > "Hosts", select the host you want to configure, and go to the "Item" tab. Open the item and set the "Type" to either "Zabbix agent (active)" or "Zabbix agent (passive)" to specify the check type for the item.
Conclusion
To get the most out of Zabbix Agent Checks, it is important to understand the differences between Active and Passive checks and to configure them according to your needs and we looked into these two types and learned how to configure them.