Where is data preprocessing defined for a host in Zabbix?

In Zabbix, data preprocessing is defined at the item configuration level. This means that each individual item can have its own specific preprocessing steps applied to the data it collects before the data is used for monitoring or triggering actions.

Preprocessing allows users to manipulate the data collected by an item to ensure it meets their needs. For example, users can format, convert, or filter data points directly within the item settings. This level of customization is crucial for ensuring that the data is in the correct format and is relevant for the specific monitoring tasks.

Though other areas like host configuration or global settings relate to how hosts and items are monitored, they do not provide the same granular control over how data is processed as the item configuration does. This approach aligns with Zabbix's design to keep configurations modular, allowing for tailored data processing for each monitored item on a host.