It's quite common, these days, to find tools that use
HTTP as a way to post events in realtime to a remote
web-server as a "callback".

This kind of scenario can be used to integrate zabbix
with other management tools like huawei e-Sight,
to receive alarms and other data in real-time when
the changes happen, thus allowing an integration
where zabbix perform "indirect" monitoring of
devices.

Actually, it's possible to do so using SNMP traps, but
using http as a transport protocol, could allow more
applications and not just specialized devices to POST
their own alarms or data if necessary, being HTTP
widely known and used in a world made of micro-
services and also being a less specialized protocol than
SNMP or IPMI.

Not sure if this could be carried out by the agent instead
of the server