In aggregate checks Zabbix server collects aggregate information from items by doing direct database queries.
Aggregate checks do not require any agent running on the host being monitored.
The syntax of the aggregate item key is:
groupfunc["host group","item key",itemfunc,timeperiod]
Supported group functions (groupfunc) are:
|grpsum||Sum of values|
Multiple host groups may be included by inserting a comma-delimited array. Starting with Zabbix 3.2.2, specifying a parent host group will include the parent group and all nested host groups with their items.
All items that are referenced from the aggregate item key must exist and be collecting data. Only enabled items on enabled hosts are included in the calculations.
Supported item functions (itemfunc) are:
|count||Number of values|
|sum||Sum of values|
The timeperiod parameter specifies a time period of latest collected values. Supported unit symbols can be used in this parameter for convenience, for example '5m' (minutes) instead of '300' (seconds) or '1d' (day) instead of '86400' (seconds).
Timeperiod is ignored by the server if the third parameter (item function) is last and can thus be omitted:
groupfunc["host group","item key",last]
An aggregate item may become unsupported in several cases:
Examples of keys for aggregate checks:
Total disk space of host group 'MySQL Servers'.
Average processor load of host group 'MySQL Servers'.
5-minute average of the number of queries per second for host group 'MySQL Servers'.
Average CPU load on all hosts in multiple host groups.
grpavg[["Servers A","Servers B","Servers C"],system.cpu.load,last]